PRAZIQUANTEL
 Common Tradenames (See Complete Tradename Listing)
 BILTRICIDE
 Class
 antihelmintic
 Dosage, Adult (usual)
 Clonorchiasis: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Opisthorchiasis: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Schistosomiasis: 20 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals) (see Administration)
 Intestinal flukes: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 North American liver fluke 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Nanophyetus salmincola: 20 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Paragonimus westermani (lung fluke): 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
for 2 days
 Tapeworm (fish, beef, pork, dog): 5-10 mg/kg ORALLY once
 Hymenolepis nana (dwarf tapeworm): 25 mg/kg ORALLY once
 Dosage, Pediatric, (usual)
 Safety in children less than 4 yr old has not been established
 Clonorchiasis: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Opisthorchiasis: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Schistosomiasis: 20 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals) (see Administration)
 Instestinal flukes: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 North American liver flukes: 25 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Nanophyetus salmincola: 20 mg/kg ORALLY 3 times over 1 day (at 4-6 hr intervals)
 Paragonimus westermani (lung fluke): 25 mg/kg ORALLY 3 times per day (at 4-6 hr intervals) for
2 days
 Tapeworm (fish, beef, pork, dog): 5-10 mg/kg ORALLY once
 Hymenolepis nana (dwarf tapeworm): 25 mg/kg ORALLY once
 Administration
 bitter taste; do not chew; take wtih liquid at meals
 schistosomiasis due to S haematobium or S mansoni may be treated with 40 mg/kg in 2 divided
doses over 1 day
 How Supplied
 600 MG TABLET
 Indications
 FDA labeled indications
 Clonorchiasis sinensis (Chinese liver fluke)
 Opisthorchiasis viverrini (South East Asian liver fluke)
 Schistosomiasis (Bilharziasis; S haematobium, S japonica, S mansoni, S mekongi)
 Non-FDA labeled indications
 Fasciolopsis buski, Heterophyes heterophyes, Metagonimus yokagawai (intestinal
flukes)
 Metorchis conjunctus (North American liver fluke)
 Nanophyetus salmincola
 Paragonimus westermani (lung fluke)
 Tapeworm, (intestinal adult; Diphyllobothrium latum (fish), Taenia saginata (beef),
Taenia solium (pork), Dipylidium caninum (dog), Hymenolepis nana (dwarf tapeworm)

.5 THERAPEUTIC USES
 A. CLONORCHIASIS/OPISTHORCHIASIS
FDA Labeled Indication
 1. OVERVIEW:
FDA APPROVAL: Adult, yes; pediatric, yes (4 years
and
older)
EFFICACY: Adult, effective; pediatric, effective
DOCUMENTATION: Adult, excellent; pediatric, good
 2. SUMMARY:
- PRAZIQUANTEL has produced
Clonorchis/Opisthorchis
(LIVER FLUKES) cure rates of 76% to 100%
- Various dosing regimens have been beneficial,
including 75 to 90 milligrams/kilogram (mg/kg)
in
3 divided doses for 1 to 2 days OR 40 to 50
mg/kg
as a single dose
- Repeat PRAZIQUANTEL dosing has raised the cure
rates
 3. ADULT:
 a. PRAZIQUANTEL is indicated for the treatment of Clonorchis
Sinensis/Opisthorchis Viverrini (approval of this indication was based on
studies in which the two species were not differentiated). Cure rates from a
single treatment course of 75 to 90 milligrams/kilogram (mg/kg) for one day in
three divided doses range from 76% to 100%. In some patients, a second
course may be necessary for complete cure (Pungpak et al, 1997; Mandell et
al, 1990; Yangco et al, 1987; O'Keefe & Edgett, 1986; Jong et al, 1985; Rim et
al, 1981). The recommended dose for clonorchiasis is 75 mg/kg given in 3
divided doses for 1 day (Prod Info Biltricide(R), 1995).
 b. A single dose of PRAZIQUANTEL (40 mg/kg) for the treatment of
Opisthorchis viverrini showed a 98% cure rate in a community study in eastern
Thailand (n=579) (Pungpak et al, 1997). Patients had mild to moderate severity
liver fluke infection. Side effects were minimal (facial edema, 1; maculopapular
rash, 1).
 c. In 8 trials involving 584 patients with Opisthorchis viverrini, 100% cure rates
were associated with the following PRAZIQUANTEL dosage regimens: 50
mg/kg every day X 1 day and 25 mg/kg 3 times a day X 2 days (Wegner,
1984).
 d. Thirty age-matched southeast Asian refugees infected with Clonorchis
sinensis/Opisthorchis viverrini were enrolled in a double-blind, placebo
controlled trial to evaluate the efficacy and safety of PRAZIQUANTEL therapy
(25 mg/kg every 4 hours X 3 doses). Nonresponders from the placebo group
were treated with PRAZIQUANTEL. Of the 22 who received PRAZIQUANTEL
(13 from PRAZIQUANTEL group and 9 from placebo group), seventeen (77%)
were cured after 1 treatment course and the remaining 5 were cured after 2
treatment courses. Common side effects included dizziness, nausea, malaise,
and headache, but these were mild and lasted no longer than 48 hours
(O'Keefe & Edgett, 1986).
 e. In 1 trial involving 5 patients with Opisthorchis felineus infections, a 100%
cure rate was achieved with PRAZIQUANTEL 25 milligrams/kilogram 3 times a
day X 1 day (Wegner, 1984).
 f. Sixty-three patients with known C sinensis infection received
PRAZIQUANTEL in a single blind study. Twenty-eight patients received 40
mg/kg in a single dose on 1 day. Thirty-five patients received 3 doses of 25
mg/kg on a single day. Thirty of 35 who received 3 doses of 25 mg/kg on a
single day were parasitologically cured completely 60 days after therapy. In 4
of 24 patients with moderate infection and 1 of 7 with heavy infection a very
small number of eggs was detected at 1 or 2-month follow-up exam. These
patients were treated again with the same dosage and were completely cured
60 days after the second treatment. Seven of the 28 patients who received 40
milligrams/kilogram were cured 60 days after therapy. The overall egg
reduction rate was 95.5%, however, the 21 uncured patients received an
additional single dose of 40 milligrams/kilogram (mg/kg) and 7 of these 21
were cured. The 14 patients who remained uncured showed egg reduction
rates in excess of 90%. Few adverse effects were observed (Rim et al, 1981).
 g. One study demonstrated a 91% cure rate in 22 patients with
Clonorchiasis/Opisthorchis infections after receiving PRAZIQUANTEL 90
milligrams/kilogram divided into 3 equal doses (one-day therapy) (Horstmann
et al, 1981).
 B. CYSTICERCOSIS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective; pediatric,
possibly effective
DOCUMENTATION: Adult, good; pediatric, good
 2. SUMMARY:
- PRAZIQUANTEL is effective treatment of
cysticercosis and neurocysticercosis in adults
and
children, although some forms of the disease do
not
respond to PRAZIQUANTEL
- Corticosteroids reduce the inflammatory response
to
treatment
 3. ADULT:
 a. The recommended praziquantel dosage for neurocysticercosis is 50
mg/kg/day orally for 14 to 15 days. Praziquantel therapy is recommended for
those with: (1) active cerebral cysticercosis with cysts in the brain parenchyma
or subarachnoid space, (2) cysts in brain parenchyma, subarachnoid space,
and ventricular system (although these patients might need surgery later), (3)
miliary cysticercosis, when many cysts are likely to be too small for detection
by computerized tomography (CT) scanning (Webber, 1994; Nash & Neva,
1984).
 b. For NEUROCYSTICERCOSIS, an alternative dosing regimen has been
suggested which is designed to take advantage of the pharmacokinetics of
the drug. The regimen is a 1-day course including 3 oral doses of 25
milligrams/kilogram at 2-hour intervals, increasing the time the parasite is
exposed to high drug concentrations. The results appeared to attain similar
cysticidal effects to longer courses. Advantages are greater compliance and
lower cost (Sotelo & Jung, 1998).
 c. Fever, headache, nausea, vomiting, meningismus, and increased
intracranial pressure are associated with PRAZIQUANTEL therapy, suggesting
an inflammatory response induced by destruction of cysts. Corticosteroid
administration (prednisone 30 to 40 milligrams (mg)/day or dexamethasone 12
to 16 mg/day) is strongly recommended to reduce these symptoms. Some
forms of the disease, such as intraventricular cysticercosis, do not respond
well to praziquantel and surgical intervention is required. In many cases, the
infection has a fairly benign course (Webbe, 1994). Some clinicians have
questioned the need and efficacy of PRAZIQUANTEL in the treatment of
intraparenchymal neurocysticercosis because the disease is self-limiting and
spontaneous resolutions have occurred in children with supportive treatment
alone (Moodley & Mossa, 1989). In children, this disease is often benign and
self-limiting with epilepsy as the major problem. In adults, however, the course
is more frequently chronic and severe, and PRAZIQUANTEL greatly improves
the prognosis in most of the these patients (Sotelo, 1989).
 d. Six patients with CHRONIC CYSTICERCAL MENINGITIS, a pernicious form
of neurocysticercosis, were treated with 3 to 6-month courses of
PRAZIQUANTEL, corticosteroids, and ventriculoperitoneal shunting. Medical
treatment with PRAZIQUANTEL was unsuccessful in all cases and no
improvement was observed either clinically or in the cerebrospinal fluid (CSF).
The most common clinical sequelae were blindness due to optic atrophy,
dementia, gait ataxia, and urinary incontinence. Several authors have
proposed that chronic cysticercal meningitis may be caused by a specific
form of neurocysticercosis, Cysticercosis racemosis which responds poorly to
treatment. This is in contrast to parenchymal neurocysticercosis, caused by
Cysticercosis cellulosae, which responds quite well to PRAZIQUANTEL
(Joubert, 1990). Two reports (deGhetaldi et al, 1984; Ciferri, 1984) emphasize
the importance of the simultaneous administration of corticosteroids and
PRAZIQUANTEL in patients with cysticercosis of the brain parenchyma. Lifethreatening inflammatory responses induced by the destruction of parasites
with PRAZIQUANTEL can be diminished by the use of corticosteroids.
 e. One study evaluated PRAZIQUANTEL therapy (50 milligrams/kilogram orally
daily for 15 days) in the treatment of active NEUROCYSTICERCOSIS in 35
patients, with follow-up for 1 year (Sotelo et al, 1985). Ninety-one percent of
patients with parenchymal cysts improved with treatment, based upon CT and
CSF analysis; 47% of patients with chronic arachnoiditis experienced
remission. Similar results were found by others (LeBlanc et al, 1986).
 4. PEDIATRIC:
 a. Practitioners treated 6 PEDIATRIC PATIENTS diagnosed with
neurocysticercosis with a 2-week course of PRAZIQUANTEL, 50 milligrams
(mg)/kilogram (kg)/day in 3 divided doses and prednisone, 2 mg/kg/day (Kalra
et al, 1987). All 6 patients showed clinical improvement. Symptoms
disappeared and no recurrence was observed during a follow-up of 18 +/- 3
months. Headache, vomiting and seizures were observed in 2 cases following
PRAZIQUANTEL therapy. These symptoms were controlled with
ACETAZOLAMIDE with or without MANNITOL. CT scans reverted to normal in
5 of 6 patients 6 to 12 weeks after therapy. Similar results were found by others
(Norman & Kapadia, 1986).
 C. DIPHYLLOBOTHRIUM INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Effective in treating diphyllobothrium
infections
 3. ADULT:
 a. Praziquantel was effective in treating DIPHYLLOBOTHRIUM
NIHONKAIENSE infection in 3 Japanese patients. The patients received a
single dose of 7 to 25 milligrams/kilogram of praziquantel. All patients expelled
the tapeworm with scolex 2 to 5 hours after taking praziquantel and no side
effects were noted (Ohnishi & Murata, 1993).
 b. A single dose of praziquantel 5 to 10 milligrams/kilogram is efficacious
(greater than 95% rate of cure) in the treatment of diphyllobothriasis (Schantz,
1996).
 D. ECHINOCOCCUS GRANULOSUS INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Used as adjunct to surgery for hydatid cysts
- Drug activity against the larval stages of the
dog
tapeworm, Echinococcus granulosus
 3. ADULT:
 a. PRAZIQUANTEL failed to kill the germinal layer of HYDATID CYSTS from
which the larvae develop, despite killing the protoscolices in the cyst fluid
(Conlon & Ellis, 1985). Other animal studies have shown similar lack of efficacy
of PRAZIQUANTEL in the treatment of hydatid disease (Wegner, 1984).
PRAZIQUANTEL should not be used as the sole treatment of inoperable
hydatid cysts, but may prove to be of value as an adjunct to surgical excision
if it kills the germinal matter that is spilled from the cysts at operation and is
unprotected by membranes.
 E. FASCIOLOPSIS BUSKI INFECTION
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, poor
 2. SUMMARY:
- PRAZIQUANTEL dosed as 75 milligrams/kilogram/day
in
3 divided doses for 1 day of therapy is
considered
the drug of choice for the treatment of
Fasciolopsis
buski infections (Anon, 1991)
 F. HYMENOLEPIS NANA INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Effective treatment for Hymenolepis infections
 3. PEDIATRIC:
 a. PRAZIQUANTEL was effective in treating H nana infection TAPEWORM
INFECTION in 155 children. Sixty-five children received 25 milligrams/kilogram
in a single dose. Sixty-five children received 15 milligrams/kilogram and 25
received 10 milligrams/kilogram. Parasitological cure as determined by
microscopic stool examination on days 5 to 7, 10 to 20, and 15 to 17 after
dosing demonstrated cure rates in 64 (98.5%) of those children receiving 25
milligrams/kilogram, in 61 of 65 (93.8%) given 15 milligrams/kilogram and 19 of
25 (76%) of those given 10 milligrams/kilogram. The authors reported no side
effects associated with therapy (Schenone, 1980).
 G. METAGONIMUS YOKOGAWAI INFECTION
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, effective
DOCUMENTATION: Adult, good
 2. SUMMARY:
- PRAZIQUANTEL dosed as 75 milligrams/kilogram/day
in
3 divided doses for 1 day of therapy is
considered
the drug of choice for the treatment of
Metagonimus
yokogawai (INTESTINAL FLUKES) infections
(Anon, 1991)
 H. NANOPHYETIASIS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Limited data suggest that PRAZIQUANTEL may have
efficacy against nanophyetiasis
 3. ADULT:
 a. Nanophyetiasis is a newly described zoonotic disease of the coastal US
Pacific Northwest and is acquired by ingestion of raw, home-smoked, or
incompletely cooked fish, from coastal streams and rivers. Nine patients with
positive stool tests for Nanophyetus salmincola were treated with
PRAZIQUATEL 60 milligrams/kilogram for 1 day, in 3 divided doses. Prior to
treatment, five patients presented with histories of gastrointestinal complaints
and five had eosinophilia. Follow-up stool exams were performed 2 to 12
weeks after treatment, and in all cases, were negative for eggs of
Nanophyetus. Seven of nine patients noted prompt resolution of symptoms
following therapy. Symptoms persisted in 2 patients, who subsequently were
thought to have had pre-existing gastrointestinal tract problems. No adverse
drug reactions were reported. Nanophyetiasis is an underreported zoonotic
disease that may be the most commonly encountered trematodiasis endemic
to North America. The use of PRAZIQUANTEL in its treatment appears to be
efficacious (Fritsche et al, 1989).
 I. PARAGONIMIASIS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, effective; pediatric, effective
DOCUMENTATION: Adult, fair; pediatric, fair
 2. SUMMARY:
- Paragonimiasis is caused by the lung fluke
Paragonimus westermani
- PRAZIQUANTEL is the drug of choice to treat
adult
and pediatric paragonimiasis
- PRAZIQUANTEL has a cure rate of approximately
90% or
greater
 3. ADULT:
 a. Paragonimiasis is endemic in areas of the world where freshwater crab,
crayfish, or shrimp are eaten raw, pickled, or undercooked. The disease is
secondary to the Oriental lung fluke PARAGONIMUS WESTERMANI. One
study reported an 85.7% cure rate in 7 patients at 3 months following an oral
course of PRAZIQUANTEL therapy (75 milligrams/kilogram/day orally for 2
days) (Johnson et al, 1985). A 100% cure rate was observed at 4 months. The
recommended dose for PARAGONIMIASIS is 75 milligrams/kilogram in 3
divided doses for 2 days (Mandell et al, 1990).
 b. In 3 trials involving 83 patients with P westermani infections, a 100% cure
rate was achieved with PRAZIQUANTEL 25 milligrams/kilogram three times a
day for 3 days. In 1 trial of 13 patients with P heterotremus infection, a cure
rate of 76.9% was achieved with 25 milligrams/kilogram three times a day for 1
day. In 6 patients with P uterobilateralis infection, and 19 patients with
Paragonimus spp in Ecuador, 100% cure rates were achieved with
PRAZIQUANTEL 25 milligrams/kilogram three times a day for 2 days. With
regard to susceptibility, Paragonimus spp can be placed between S
japonicum, C sinensis, and O viverrini on the one hand, and F hepatica on the
other. Susceptibility to PRAZIQUANTEL appears to depend on the ease with
which the drug can penetrate into the interior of the parasite. The thickness of
tegument increases remarkably in the order in which these parasites are
mentioned. This explains why a longer exposure to the drug is necessary for
Paragonimiasis (Wegner, 1984).
 c. Practitioners treated 6 patients with documented P uterobilateralis (lung
fluke) with PRAZIQUANTEL 20 milligrams/kilogram 3 times a day for 2 days
(Monson et al, 1983). No side effects were noted in any of the patients. Within
48 hours of treatment hemoptysis stopped and cough completely disappeared
within the next days. Radiographic changes showed improvement as early as
2 weeks after treatment and complete resolution as early as 5 months after
treatment. Long term follow-up at 5 to 8 months showed complete resolution.
 4. PEDIATRIC:
 a. A case report describes pleural paragonimiasis in an 11.5-year-old Laotian
boy who was successfully treated with PRAZIQUANTEL (Heath & Marshall,
1997). Ultrasound examination of the chest showed a massive left pleural
effusion enclosing mobile debris. On thoracotomy, thick fluid, proteinacious
material, and a fluke (P westermani) were found. The boy was administered a
3-day course of praziquantel and discharged.
 J. SCHISTOSOMIASIS
FDA Labeled Indication
 1. OVERVIEW:
FDA APPROVAL: Adult, yes; pediatric, yes (4 years
and
older)
EFFICACY: Adult, effective; pediatric, effective
DOCUMENTATION: Adult, excellent; pediatric,
excellent
 2. SUMMARY:
- Praziquantel is considered mainstay of treatment
and critical for community-based control
programs
-- Cure rates produced by PRAZIQUANTEL range from
75% to 95%
-- Same effectiveness in HIV-infected patients
-- Not appropriate for prophylaxis
-- Resistance may be emerging
(Ross et al, 2002)
- Dosing regimens include 20 milligrams/kilogram
(mg/kg) three times a day for 1 to 3 days OR 40
to
60 mg/kg in 2 divided doses for 1 day OR 40 to
50 mg/kg as a single dose
- Higher single doses have resulted in greater
adverse
effects
- A case of schistosomiasis resistant to 3 courses
of
praziquantel treatment was reported
 3. ADULT:
 a. Clinical trials have shown PRAZIQUANTEL to be very effective in the
treatment of schistosomal infections. Depending on the specific species being
treated, cure rates range from 75% to 95% following single dose or 1-day
divided dose therapy (Stelma et al, 1995; Pollner et al, 1993; Homeida et al,
1988; Watt et al, 1986; Kardaman et al, 1983; Coutinho et al, 1983; Oyediran et
al, 1981; da Silva et al, 1981; Omer, 1981; Katz et al, 1981). For Schistosoma
mansoni or haematobium, the dose of PRAZIQUANTEL for adults and children
over 4 years (greater than 20 kg) is 40 milligrams/kilogram (mg/kg) per day
divided in 2 doses for 1 day; for Schistosoma japonicum or mekongi, the dose
is 60 mg/kg/day in 3 divided doses for 1 day. Doses should be given at least 4
to 6 hours apart. Administration of a single large dose is associated with a
higher incidence of adverse effects (Katz et al,1979).
 b. Three courses of praziquantel, separated by a year or more, failed to cure a
26-year-old British man of schistosomiasis, acquired during a trip to Kenya,
despite the absence of any opportunity for reinfection. A few months after
returning from Kenya, the man was asymptomatic, but serological testing was
strongly positive for schistosomiasis (level 4). He was treated with a single
dose of praziquantel 40 milligrams (mg). Eighteen months later, his serology
was more strongly positive (level 5). He was treated with another dose of
praziquantel 40 mg. In the third year, he experienced non-specific malaise,
intermittent abdominal discomfort, and semi-solid stools. He had mild
peripheral blood eosinophilia, for which no cause (eg, Strongyloides infection
or filariasis) could be found. Stool and urine specimens were negative for ova,
cysts, and parasites, but schistosomiasis serology was elevated (level 5).
Biopsies of bowel mucosa showed inflammation and eggs of S. mansoni. He
was given a third treatment of praziquantel 40 mg. A year later, symptoms and
laboratory tests remained the same. An alternative treatment, oxamniquine,
was unavailable in Britain, and he was therefore treated with praziquantel 40
mg/day for 3 consecutive days. Symptoms abated and serology normalized.
At no time during treatment did the man return to an area with endemic
schistosomiasis (Lawn et al, 2003).
 c. Comparison studies of two dosages (40 mg/kg as a single dose or 60 mg/kg
in 2 divided doses) found little difference in efficacy between the two dosing
regimens; due to practicality, the single-dose regimen was recommended for
treatment of large populations or community-wide programs, while the 2-dose
treatment was recommended for individual treatment as the lower doses were
associated with reduced side effects (Abu-Elyazeed et al, 1997; Guisse et al,
1997). In the former study, 1588 patients between the ages of 5 and 50 years
with Schistosoma mansoni infection were enrolled in 2 Egyptian study sites,
Om El-Laban and Farshout. Failure rates were 14.5% and 4.1% for the single
and 2-dose treatments, respectively. In the latter study, 130 children in
northern Senegal were studied. No significant difference in cure rates was
found between the 1 and 2-dose regimens. Mean egg counts were reduced by
99% in both groups.
 d. Mass PRAZIQUANTEL therapy was an effective method of reducing the
prevalence of Schistosoma haematobium in the village of El Absi in Giza,
Upper Egypt. Prevalence of schistosomiasis at the 1-year follow-up was
reduced by 83.6% from 23.1% to 3.8%. Among the infected residents,
geometric mean egg counts decreased from 12.4 to 3.1 eggs per 10 mL of
urine, a four-fold decrease. At baseline, all residents of the village were offered
praziquantel (40 milligrams/kilogram as a single dose) and screened for S
haematobium ova in the urine. A month later all who had tested positive were
re-examined for schistosomiasis and re-treated with praziquantel if still
positive. At 1 year, all village residents were re-examined, and findings
compared with baseline (Talaat & DeWolfe Miller, 1998).
 e. Researchers treated 352 Senegalese infected with S mansoni, with 40
mg/kg of praziquantel (Stelma et al, 1995). The parasitologic cure rate 12
weeks after therapy was 18%. The frequency of egg counts with more than
1000 eggs per gram (epg), decreased from 41% to 5%. The mean egg count
of those remaining positive was reduced by 86%. The low cure rate may be
due to intense transmission and/or undeveloped immune responses in this
recently exposed population. The authors also demonstrated praziquantel
resistance in at least one S mansoni isolate from this area in Senegal in the
same group. Oxamniquine is a viable treatment alternative, as strains resistant
to praziquantel in animal models respond to this drug.
 f. One report describes the effectiveness of single-dose PRAZIQUANTEL
therapy (60 milligrams/kilogram) in 9 Filipino patients with seizures caused by
cerebral S JAPONICUM infection (Watt et al, 1986). Eight patients were cured
and discharged from the study seizure-free, without anticonvulsants, an
average of 6 months after therapy. Another report describes a rare case of
CEREBRAL SCHISTOSOMIASIS caused by S haematobium in a 30-year-old
male (Pollner et al, 1993). The patient responded to therapy with praziquantel
(20 mg/kg orally 3 times a day x 3 days), dexamethasone, and phenytoin.
 g. Researchers studied the efficacy and tolerance of PRAZIQUANTEL in the
treatment of active S MANSONI infection in 59 patients with SYMMERS'
PERIPORTAL FIBROSIS (Homeida et al, 1988). They compared these results
with a similarly treated group of 238 patients without liver involvement. Patients
were treated with a single dose of 40 milligrams/kilogram (mg/kg) of
PRAZIQUANTEL. Six months after treatment 30 patients (51%) of the Symmers'
group and 138 (58%) of the non-Symmers' group were cured of their infection.
There was no significant difference in side effects or the drug's antischistosomal activity between the 2 groups.
 h. No significant difference was observed between 3 doses of 20 mg/kg or 1
dose of 50 mg/kg. Twenty-five of 26 (96%) patients followed at 1 year were
cured. Others reported a 78.9% cure rate following single doses of 30 mg/kg
and an 86.3% cure rate following doses of 20 mg/kg twice daily at 6-month
follow-up (Coutinho et al, 1983). Noncured patients showed a marked
reduction in the number of eggs eliminated in the feces.
 4. PEDIATRIC:
 a. MONOTHERAPY
 (1) One report describes the case of S haematobium infection in a 7year-old expatriate boy that persisted despite multiple courses of
praziquantel therapy (Herwaldt et al, 1995). The authors address
various host and parasite factors than can cause suboptimal
response to praziquantel. They recommend that physicians caring for
patients unresponsive to praziquantel contact the U.S. Centers for
Disease Control at (404) 488-7760 to discuss further treatment
options.
 (2) Another study showed substantial improvement of PERIPORTAL
FIRBROSIS in 420 S mansoni-infected Sudanese school children
seven months after praziquantel therapy (Mohamed-Ali et al, 1991).
Patients were treated at random with either 20 mg or 40 mg/kg of
praziquantel. No significant difference was found between these two
groups in reducing egg excretion or reversing periportal fibrosis.
Children younger than 11 years of age had a higher rate of complete
reversibility than older ones. Periportal fibrosis was graded into 3
degrees and was based on the degree of hyperechoic periportal
bands in the liver. Periportal fibrosis grade II decreased from 22.9%
to 6.7% and grade III from 5.2% to 1.6%. The percentage of patients
with hepatomegaly also decreased significantly (11.6% to 6.9%;
p=0.001).
 (3) Another study examined the impact of annual PRAZIQUANTEL
therapy (40 mg/kg as a single dose) on Symmers' fibrosis induced by
Schistosoma mansoni (Homeida et al, 1991). Forty-eight Sudanese
villagers, having various degrees of Symmers' fibrosis, were followed
from 1986 to 1989. Results indicated a significant improvement
between the fibrotic status of patients in 1986 and their fibrotic status
in 1989. After 3 years of therapy, 12 of 48 patients (25%) no longer
had detectable fibrosis, while 16 showed a decrease in the amount of
fibrosis in their livers. Therapeutic response was not dependent on
sex, pretreatment egg count, or pretreatment liver or spleen size.
PRAZIQUANTEL appeared to be able to block and reverse the
disease process in Sudanese children and adults.
 (4) PRAZIQUANTEL therapy in children may promote an acquired
immune response that will protect the individual against future
episodes of schistosomiasis (Mutapi et al, 1998). A study in 41
children (5 to 16 years of age) with Schistosoma haematobium found
that after use of praziquantel, predominant antibody responses
switched from an IgA to an IgG1-specific response. IgG1 responses
are more commonly associated with adult immune system reactions
that show acquired resistance to the infecting agent. The mechanism
may be alterations in cytokine concentrations related to the release of
antigens by dead or damaged schistosomes disabled by exposure to
praziquantel.
 (5) In 151 Zambian school children, 3 different dosage regimens of
PRAZIQUANTEL were tested for efficacy against S HAEMATOBIUM.
Regression analysis indicated that a single dose of 40
milligrams/kilogram proved better than the other two regimens (30
milligrams/kilogram as a single dose and 20 mg/kg X 2 doses) and
produced cure rates of 98% at 3 months, 82% at 7 months, 70% at 1
year, and 58% at 2 years. The authors stated that "failures" up to 7
months could probably be attributed to true drug failures, whereas,
treatment failures between 7 and 24 months most probably were
associated with reinfection rather than drug failure. Cure rates did
vary inversely with the intensity of excretal egg output (Davis et al,
1981).
 b. COMBINATION THERAPY
 (1) Simultaneous OXAMNIQUINE and PRAZIQUANTEL in low single
doses of 7.5 and 15 milligrams/kilogram, respectively, were effective
in treating school age children infected with S MANSONI,
HAEMATOBIUM, or concomitant infection. There was a greater than
93% egg count reduction at 1 month, 3 months, and 6 months after
treatment (Pugh & Teesdale, 1983).
 K. TAENIA INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, poor
 2. SUMMARY:
- A single
milligrams/
kilogram
of
cure) in
1996)
- Close to
was
achieved
kilogram
dose of praziquantel 5 to 10
is efficacious (greater than 95% rate
the treatment of taeniasis (Schantz,
100% efficacy against Taenia saginata
with doses as low as 2.5 milligrams/
(Pawlowski, 1991)
 4.6 COMPARATIVE EFFICACY AND EVALUATION WITH OTHER SIMILAR THERAPEUTIC AGENTS
 A. ARTEMISININ
 1. CLONORCHIASIS
 a. Praziquantel was immediately more efficacious than artemisinin in the
treatment of Clonorchis sinensis (C sinensis) infection, yet this difference was
not maintained at 5-week follow-up, in a randomized, comparative, pilot study.
Patients with confirmed presence of C sinensis eggs in stool samples received
either oral praziquantel 25 milligrams/kilogram (mg/kg) once-daily for 3 days
(n=21), or oral artemisinin 500 mg twice-daily for 5 days (n=21). Stool sample
egg counts were significantly lower after treatment with praziquantel compared
with artemisinin (p less than 0.001 at day 6, and p=0.002 at week 5). The
number of patients without detectable C sinensis eggs in follow-up stool
samples was significantly higher at 6 days post-treatment in the praziquantel
group compared with patients taking artemisinin (71% and 19%, respectively;
p=0.001). The percentage of praziquantel-group patients with egg-free stool
samples decreased to 29% by follow-up week 5, perhaps reflective of a lessthan-effective dosing regimen. Concurrent infection with Trichuris trichiura and
Ascaris lumbricoides was incidentally found in all patients treated; it is notable
that the 2 other intestinal helminths were unaffected by either treatment (Tinga
et al, 1999).
 B. ALBENDAZOLE
 1. SUMMARY
 a. ALBENDAZOLE has a higher rate of eradication of parenchymal brain cysts
compared with PRAZIQUANTEL
 b. ALBENDAZOLE and PRAZIQUANTEL have comparable safety profiles
 c. ALBENDAZOLE attains a higher concentration in cerebrospinal fluid and is
less likely to interact with seizure drugs (eg, phenytoin, carbamazepine)
 2. NEUROCYSTICERCOSIS
 a. SUMMARY: In clinical trials comparing the efficacy of ALBENDAZOLE and
PRAZIQUANTEL in the treatment of NEUROCYSTICERCOSIS, albendazole
shows equal or greater efficacy than praziquantel. Albendazole 15 to 20
milligrams/kilogram (mg/kg) daily for 21 to 30 days compared with
praziquantel 50 mg/kg/day for 14 to 21 days results in clinical improvement
rates of 76% to 88% and 50% to 73%, respectively. Concomitant steroid and
anticonvulsant therapy is usually administered (Takayanagui & Jardim, 1992;
Cruz et al, 1991; Sotelo et al, 1988). The 2 drugs have generally comparable
safety profiles. However, albendazole appears to be the drug of choice over
praziquantel due to its higher concentration in cerebrospinal fluid, greater
eradication rate in parenchymal brain cysts, lower likelihood of interactions
with anticonvulsant medications, and cost advantage (Mehta et al, 1998). The
results of some trials need to be interpreted with caution as some of them are
neither double-blinded nor randomized (Takayanaqui & Jardim, 1992).
 b. Albendazole 15 mg/kg/day orally for 1 month was reported as effective as
praziquantel 50 mg/kg/day orally for 2 weeks in the treatment of parenchymal
brain cysticercosis in a randomized study involving 25 patients. In the 10
patients assigned to albendazole, a 76% remission of lesions was observed,
with a reduction in the number of cysts in 9 cases and disappearance of all
parenchymal cysts in 6. With the 10 patients on praziquantel, a single course
induced a 73% remission of lesions, with a reduction in the number of lesions
in 9 and disappearance of all parenchymal cysts in 7. In 5 control patients who
received only anticonvulsants, steroids, and analgesics, the cystic lesions
remained unchanged (Sotelo et al, 1988).
 c. One study compared albendazole and praziquantel in the treatment of
neurocysticercosis in 100 patients (Cruz et al, 1991). Overall clinical
improvement occurred in 84% of cases treated with albendazole, compared
with 62% of those treated with praziquantel (a statistically significant
difference). Patients in both groups also received concomitant steroid therapy
during treatment. There were no significant side effects with either treatment.
 d. Researchers performed a prospective study with 59 consecutive patients
comparing the efficacy of albendazole (n=21) and praziquantel (n=22) in the
treatment of neurocysticercosis (Takayanagui & Jardim, 1992). Sixteen
patients were treated with symptomatic drugs (dexamethasone and antiseizure medications) and used as controls. Praziquantel was given at a dose
of 50 mg/kg/day for 21 days; albendazole at 20 mg/kg/day for 21 days.
Evaluation of therapeutic response consisted of cyst counts before and 6
months after the end of therapy. Both drugs were effective when compared to
the control group. Comparatively, albendazole showed more efficacy than
praziquantel in reducing the number of cysts in the CT scan (88% vs 50%),
respectively). However, the results of this study need to be interpreted with
caution as the study was neither randomized nor double-blinded. The
population samples were small and the patients in the albendazole group
were, on the average, older and had fewer cysts. The follow-up time for the
control group was also considerably shorter than the two treatment groups,
and therefore, the control group might not have reflected the natural clinical
course of neurocysticercosis.
 C. METRIFONATE
 1. SCHISTOSOMA HAEMATOBIUM INFECTIONS
 a. SUMMARY: Praziquantel is the drug of choice for
infections involving all 5 human schistosome species (S
haematobium, S mansoni, S mekongi, S japonicum, S
intercalatum). Metrifonate is an effective alternative to
praziquantel only for treatment of S haematobium infections.
Several controlled studies have demonstrated the superiority
of praziquantel (30 to 40 milligrams/kilogram/day, single
dose, or for 3 total doses given 2 weeks apart) in the
treatment of S haematobium infections, praziquantel appears
to more effectively reduce S haematobium egg count and
produce higher cure rates than metrifonate.
 b. One study compared the efficacy of praziquantel 40
milligrams (mg)/kilogram (kg), metrifonate 10 mg/kg, and
combined metrifonate 10 mg/kg and niridazole 25 mg/kg in
children from 2 Malawi schools (Pugh & Teesdale, 1983).
Praziquantel was the most effective with a greater than 97%
reduction in egg count demonstrated 6 months after
treatment. Combination niridazole and metrifonate therapy
accounted for a 92% reduction, whereas an 86% reduction
was seen for metrifonate alone. All of the treatments were
well tolerated. Similar results were reported by McMahon
(1983).
 c. Another study evaluated the relationships between
Schistosoma haematobium, hookworm, malaria, hemoglobin
level, splenomegaly, and hepatomegaly, before and 8
months after treatment with a single dose of metrifonate (10
mg/kg) or praziquantel (40 mg/kg) in 312 Kenyan school
children in an area where anemia, Schistosoma
haematobium, hookworm, and malaria infections are
endemic (Stephenson et al, 1989a). Eight months after
treatment, the prevalence of Schistosoma haematobium had
decreased from 100% to 62% in the metrifonate group, and
13% in the praziquantel group. Prevalence was 98% in the
placebo group. Moreover, a modest rise in hemoglobin (0.3
g/dL greater than placebo) occurred only in the metrifonate
group, whereas, the praziquantel group showed no change
in hemoglobin level. This effect on hemoglobin level may
have been due to the ability of metrifonate to decrease both
Schistosoma haematobium and hookworm egg counts,
whereas praziquantel has no effect on hookworm infection.
Both metrifonate and praziquantel in single dose are useful
for large scale chemotherapy where the goal is morbidity
reduction. Praziquantel is more effective in reducing S
haematobium egg counts and can be used for S mansoni,
but is much more costly than metrifonate, and does not
decrease hookworm incidence and anemia, whereas
metrifonate can. Treatment of S haematobium with either
drug, however, appears to have a beneficial effect on
hepatomegaly and splenomegaly in children. In another
study by these same authors, treatment of S. haematobium
infections with single-dose of metrifonate or praziquantel may
improve child growth in areas where protein-energy
malnutrition, and in case of metrifonate, hookworm infections
are endemic. The degree of growth improvement appears to
be equal with either drug regimen (Stephenson et al, 1989b).
 d. Kenya school children with Schistosoma haematobium
(n=2,493) were randomized to receive either metrifonate (10
mg/kg for three doses at 4-month intervals each year) or
praziquantel (40 mg/kg as a single dose each year) for a
period of one to three years. Results indicated significant
long-term suppression of S haematobium infection in this
population. The decrease in prevalence and intensity of
infection was maximal after two years, and suppression of
infection lasted for at least two years after discontinuation of
therapy. Comparison of metrifonate and praziquantel showed
greater suppression of infection and longer infection-free
intervals for some groups treated with praziquantel. Areas
not experiencing decreased transmission had the highest
initial prevalence, higher levels of adult infection, and the
least access to safe water (King et al, 1991).
 D. NIRIDAZOLE
 1. SCHISTOSOMA INFECTIONS
 a. Praziquantel 30 milligrams (mg)/kilogram (kg)
administered as a single oral dose was compared with
metrifonate 10 mg/kg given at 2-week intervals for 3 doses
and niridazole 25 mg/kg each day for 6 days in 90 patients
with Schistosoma haematobium. The evaluation of
therapeutic efficacy was made by parasitological
examination 2 and 4 months after therapy with 3 consecutive
daily urine examinations. Cure rates at 4 months were 27 of
30 (90%), 13 of 22 (59%), and 13 of 20 (65%) for
praziquantel, metrifonate, and niridazole respectively.
Reduction in egg excretion of noncured cases is 99%
(praziquantel), 98% (metrifonate) and 75% (niridazole)
(McMahon, 1983).
 b. Another study compared the efficacy of praziquantel and
niridazole in Schistosoma intercalatum (Feldmeier et al,
1981). Forty-five patients with documented schistosomiasis
were randomly divided into 2 groups. Group A (22 patients)
received praziquantel 30 mg/kg in 2 doses 4 hours apart.
Group B (23 patients) received niridazole in a daily dose of
25 mg/kg for 7 consecutive days. Patients receiving
niridazole also received 3 x 2 mg diazepam to avoid
neurotoxic side effects seen with this drug. Parasitologic
cure was to find the absence of eggs in 3 consecutive stool
examinations 6 weeks after therapy. Thirteen of 19 (68%)
patients treated with praziquantel were cured in contrast to 6
of 17 (35%) treated with niridazole. The incidence of adverse
effects was not significantly different and abdominal
discomfort, nausea, anorexia, diarrhea and vomiting were
only observed transiently.
 E. OXAMNIQUINE
 1. SCHISTOSOMA MANSONI INFECTIONS
 a. Praziquantel 60 milligrams (mg) per kilogram (kg) daily for
3 days was similarly effective as oxamniquine 10 mg/kg
twice daily for 1 day when assessed by 3 different stool
examination techniques (100% versus 90.3%, respectively).
However, rectal mucosa biopsy (oogram) at six months
showed only praziquantel to maintain a similarly high cure
rate (96%), while the cure rate for oxamniquine was reduced
by half (42%). Cure rates for a parallel placebo-control group
were 16% and 0% by stool exam or rectal biopsy methods,
respectively (Ferrari et al, 2003).
 b. Praziquantel provided significantly better relief of clinical
symptoms as well as improved efficacy in reducing egg
excretion than oxamniquine in a randomized, single-blind
comparative trial of single dose praziquantel (40
milligrams/kilogram (mg/kg)) compared to oxamniquine (15
mg/kg) or no treatment in 188 Tanzanian children with
Schistosoma mansoni (Rugemalila et al, 1984). Patients were
monitored 24 hours after treatment and at 1, 2, and 6 months
thereafter. Abdominal discomfort was reported more
commonly in the praziquantel group (71%) than in the
oxamniquine group (45%), however, the incidence of
somnolence, diarrhea, nausea and vomiting were about the
same for both groups. All side effects were mild and resolved
within 1 to 2 hours. Alleviation of disease symptoms was
significantly greater after 6 months in the praziquantel group
(63%) compared to the oxamniquine (32%) and
nontreatment groups (24%).
 c. Among patients who failed treatment with either
praziquantel or oxamniquine, use of the alternative agent
was highly effective resulting in negative stools in 11 of 12
cases examined 1 month after the second round of therapy.
Two hundred children were originally treated with either
oxamniquine 20 milligrams/kilogram (mg/kg) (n=90) or
praziquantel 60 mg/kg (n=110). Cure rates averaging about
85%, were similar in both groups. Children still passing eggs
two to three months after therapy were retreated with the
alternative drug. The authors suggested that patients be
treated with one drug and therapeutic failures with another to
minimize the risk of developing drug resistance (Katz et al,
1991).
 F. TRICLABENDAZOLE
 1. PARAGONIMIASIS - HUMAN
 a. In an open trial of 62 adult patients with human pulmonary
paragonimiasis due to P. mexicanus, oral triclabendazole
was superior to oral praziquantel. The patients were
randomly administered 1 of 4 regimens: triclabendazole 5
milligrams/kilogram (mg/kg) body weight daily for 3 days;
triclabendazole 10 mg/kg body weight twice daily for 1 day;
single dose of triclabendazole 10 mg/kg body weight; or
praziquantel 25 mg/kg 3 times daily for 3 days. All patients
were observed in the hospital for the first 7 days after
treatment, and then as outpatients 30, 90, and 365 days after
treatment. All hematologic, biochemical, and urine analyses
were within normal limits at all post-dose follow-up sessions
for all regimens. Adverse effects for the first 7 days were
fewer and less severe with triclabendazole than with
praziquantel, with the triclabendazole 10 mg/kg twice daily
regimen being best tolerated. Treatment efficacy was
determined by monitoring clinical response to treatment,
sputum volume and color, egg count in sputum, and time
required for patients to cease excreting Paragonimus eggs in
sputum and stool samples. Triclabendazole was superior to
praziquantel for clinical response, clearance rate of eggs
from the sputum, and amount of time before sputum volume
decreased. All patients were cleared of infection at 90 days
after treatment except for 2 of 16 patients who received the
low single-dose regimen of triclabendazole. Treatment was
repeated in these patients and no eggs were found in the
sputum of any of the patients at 365 days. Larger clinical
trials are needed in various geographic areas to determine
the most efficient dose of triclabendazole for the treatment of
human paragonimiasis (Calvopina et al, 1998).
 Contraindications
 hypersensitivity to praziquantel
 ocular cysticercosis
 Precautions
 do not drive/operate machinery day of or day following treatment
 hospitalize patient being treated for shistosomiasis or fluke infection associated with cerebral
cysticercosis

Adverse Effects
 COMMON
 malaise
 headache
 dizziness
 Drug Interactions
 carbamazepine
 fosphenytoin
 phenytoin
 Pregnancy Category
 B
 Breast Feeding
 controversial
 Notes
 each scored tablet section contains 150 mg

3.1 CONTRAINDICATIONS
 A. Hypersensitivity to PRAZIQUANTEL
 B. Treatment of ocular cysticercosis with praziquantel tablets (irreparable lesions of the eye may
occur)
 3.2 PRECAUTIONS
 A. No precautions known at time of review
 3.3 ADVERSE REACTIONS
 3.3.1 BLOOD
 A. HEMATOLOGIC EFFECTS
 1. In G6PD (glucose 6-phosphate dehydrogenase) deficient patients, no
adverse or measurable changes occurred as a result of PRAZIQUANTEL
therapy in any of the dosages given (Wegner, 1984; Qi-Hong et al, 1984).
 2. No BONE MARROW TOXICITY was observed in 30 patients with varying
degrees of liver dysfunction during the 2 weeks after PRAZIQUANTEL, 60
mg/kg orally in divided doses over 1 hour, was given. No decrease in platelet
counts, white blood cells, or red blood cells was noted (Watt et al, 1988).
 3.3.3 CENTRAL NERVOUS SYSTEM
 A. CENTRAL NERVOUS SYSTEM EFFECTS
 1. SUMMARY: In patients taking normal doses of PRAZIQUANTEL, commonly
reported CNS effects include FEVER, DIZZINESS, HEADACHE, DROWSINESS,
and MALAISE. Several cases of DELAYED CSF REACTION SYNDROME
(nuchal rigidity, papilledema, aphasia, seizures) have been reported following
treatment for neurocysticercosis. Neurological symptoms such as headaches
may also occur following single low doses of PRAZIQUANTEL.
 2. FEVER and DIZZINESS have been reported in patients receiving
PRAZIQUANTEL. In 353 patients receiving PRAZIQUANTEL, fever, was
reported in 36 (10%), and dizziness in 126 (36%) patients. These symptoms
resolved by 48 hours after dosing (El-Alamy et al, 1981).
 3. OF 30 patients with varying degrees of liver dysfunction who received 60
mg/kg orally in divided doses over 1 hour, 17 patients experienced
HEADACHE (57%) and 21 patients reported DROWSINESS (70%) (Watt et al,
1988). However, it should be noted that the manufacturer recommends that
the interval between the individual doses should be less than 4 hours and no
greater than 6 hours (Prod Info Biltricide(R), 2000).
 B. NEUROCYSTICERCOSIS
 1. A large CEREBRAL INFARCTION in a patient administered praziquantel for
neurocysticercosis may have resulted from a secondary inflammation reaction
and enhanced endarteritis caused by destruction of the cysts (Bang et al,
1997). The 59-year-old male experienced right hemiplegia, aphasia, abulia,
and weakness in his left extremities after 2 days of praziquantel 50 milligrams
(mg)/kilogram (kg)/day orally (his second course of this agent) and
prednisolone 30 mg/day. Angiography showed complete occlusions of the
right middle cerebral artery and left internal carotid artery. These clinicians
stressed the need for early start of high doses of corticosteroids concurrent
with anti-infective therapy in subarachnoid cysticerci.
 2. One author reported 3 cases of a DELAYED CSF REACTION SYNDROME
which occurred 2 weeks after completing a 14-day treatment course of
PRAZIQUANTEL and DEXAMETHASONE for neurocysticercosis (Ciferri, 1988).
Presenting symptoms included headache, nausea, vomiting, nuchal rigidity,
papilledema, increased seizure activity, transient aphasia and motor
weakness. These symptoms resolved with either conservative or steroid
treatment. Steroid administration before, during, and perhaps after the full
course of PRAZIQUANTEL may prevent this syndrome from occurring (Fong &
Cheung, 1997).
 3. In response to Ciferri's report, another practitioner stated that during and
shortly after PRAZIQUANTEL therapy, many patients experience headaches,
nausea, or seizures as a result of a strong inflammatory reaction in the host in
response to the destruction of cysticerci (Del Brutto, 1988). These symptoms
are mild and transient and usually respond to analgesics, antiemetics, or
antiepileptics, and one need not use steroids, which should be reserved for
transient therapy when severe intracranial hypertension develops. This
complication may be more likely to occur in patients with multiple cysts or
large lesions.
 4. Even low doses of PRAZIQUANTEL may precipitate inflammatory responses
that may lead to NEUROLOGICAL SYMPTOMS in patients with occult
neurocysticercosis. One report describes a case of a 12-year-old who
experienced severe headaches for 10 days following a single low dose of
PRAZIQUANTEL 5 mg/kg for the treatment of taeniasis (Flisser et al, 1993).
 3.3.4 ENDOCRINE/METABOLIC
 A. PORPHYRIA
 1. One report describes treating a 19-year-old youth who had both
schistosomiasis and a history of acute porphyria variegata with
PRAZIQUANTEL (40 mg/kg in 2 divided doses) and PREDNISONE (20
mg/day) for 3 days (Grant & Hesdorffer, 1986). An acute attack of porphyria
was not precipitated in this patient which led the authors to suggest that the
use of PRAZIQUANTEL is safe in porphyria.
 B. HYPERGLYCEMIA
 1. Varying degrees of HYPERGLYCEMIA were found in 33 of 100
neurocysticercosis patients treated with praziquantel (50 mg/kg/d x 15 days).
This hyperglycemia was benign in character, lasted while the drug was
administered, and disappeared thereafter. In one case, the patient was a
diabetic and the symptoms continued for 5 months after the end of
praziquantel therapy (Webbe, 1994).
 3.3.5 GASTROINTESTINAL
 A. GASTROINTESTINAL EFFECTS
 1. PRAZIQUANTEL is well tolerated by humans with self-limiting
gastrointestinal toxicity the most common adverse effect (Pearson & Guerrant,
1983). In a study reporting the results of 353 patients, ABDOMINAL PAIN was
seen in 133 patients, NAUSEA in 130, and VOMITING in 39. These resolved
within 48 hours of treatment (El-Alamy et al, 1981).
 2. In 30 patients with varying degrees of liver dysfunction who were given
PRAZIQUANTEL, 60 mg/kg orally in divided doses over 1 hour, DIARRHEA
was reported in 9 (30%) and the URGE TO DEFECATE was reported in 12
(40%), severe abdominal pain followed by bloody diarrhea was reported in 4
patients (13%). The pain and bloody diarrhea lasted less than 2 hours in each
case. One patient developed symptoms of mild hepatic encephalopathy due
to the bleeding, but symptoms resolved within 24 hours. The syndrome of
bloody diarrhea was not related to peak plasma concentrations of
PRAZIQUANTEL (Watt et al, 1988).
 3.3.6 KIDNEY/GENITOURINARY
 A. NEPHROTOXICITY
 1. No nephrotoxicity was noted in 30 patients with varying degrees of liver
dysfunction during the 2 weeks after PRAZIQUANTEL, 60 mg/kg orally in
divided doses over 1 hour, was given. No elevation in blood urea nitrogen
(BUN) and creatinine levels was observed (Watt et al, 1988).
 3.3.7 LIVER
 A. HEPATOTOXICITY
 1. No hepatotoxicity was observed in 30 patients with varying degrees of liver
dysfunction during the 2 weeks after PRAZIQUANTEL, 60 mg/kg orally in
divided doses over 1 hour, was given. No increase in transaminases was
noted. Mild side effects were associated with high peak concentration of
PRAZIQUANTEL, but a syndrome of severe abdominal pain followed by
bloody diarrhea was not, and its pathogenesis remains unclear (Watt et al,
1988).
 2. Minimal increases in liver enzymes have occurred in some patients
receiving PRAZIQUANTEL (Prod Info Biltricide(R), 2000).
 3.3.9 RESPIRATORY
 A. RESPIRATORY EFFECTS
 1. One report described the case of a 21-year-old male with EXUDATIVE
POLYSEROSITIS following treatment of schistosomiasis with PRAZIQUANTEL
(Azher et al, 1990). The patient received 1.8 grams of PRAZIQUANTEL as a
single dose. Four hours later, he developed a generalized maculopapular rash
with myalgia, fever, abdominal pain, diarrhea, and severe pleuritic chest pain.
He also developed pleural, pericardial, and peritoneal effusions. This was
associated with ACUTE RESPIRATORY FAILURE with ventilation-perfusion
mismatch and symptomatic ASCITES which was relieved by aspiration.
Examination of pleural and peritoneal fluid was negative for all
microorganisms, including mycobacteria. Acute respiratory failure has been
described following treatment with other antischistosomal drugs, such as
OXAMNIQUINE. This has been attributed to either a shifting of worms and ova
to the pulmonary vasculature or allergy to schistosomal antigens released after
worm death. The latter explanation was the most likely reason for this patient's
acute respiratory failure, as no worms or ova were discovered in pleural biopsy
specimens.
 3.3.10 SKIN
 A. DERMATOLOGIC EFFECTS
 1. Two of 30 patients reported a pruritic skin RASH lasting several days
following PRAZIQUANTEL therapy in a dose of 25 mg/kg every 4 to 6 hours for
3 doses (Jong et al, 1985).
 3.3.11 MUSCULOSKELETAL
 A. MUSCULOSKELETAL EFFECTS
 1. MYOSITIS, including FEVER and MYALGIA, occurred in a 26-year-old
woman diagnosed with disseminated muscular cysticercosis and given
PRAZIQUANTIL therapy. At presentation, she had complained of seizures,
headache, and lower limb weakness. On the second day of praziquantel
therapy (50 mg/kg/day), the patient experienced fever and diffuse muscle
aches, mainly of the lower limbs. Dexamethasone 6 mg/day was added to
therapy. Praziquantel was discontinued on day 7; intermittent fever persisted
for 9 additional days and myalgia for 15 more days. Even though
dexamethasone reduces praziquantel plasma concentrations, the authors
recommend its simultaneous administration (Takayanagui & Chimelli, 1998).
 3.3.12 OTHER
 A. HYPERSENSITIVITY
 1. One author describes a case of PRAZIQUANTEL HYPERSENSITIVITY
experienced by a 10-year-old boy while being retreated for neurocysticercosis
(Huang, 1992). After the second dose of a second course of PRAZIQUANTEL
(600 mg orally every 8 hours for 14 days), the patient suffered severe,
generalized urticaria covering the entire body and head, which resolved with
DIPHENHYDRAMINE and DEXAMETHASONE. Desensitization was attempted
by premedicating with steroids and HYDROXYZINE and administering 13
doses of PRAZIQUANTEL at 15-minute intervals. However, 1 hour after the last
dose, the patient experienced generalized urticaria, difficulty swallowing, and
tightness of the chest. Two days later, PRAZIQUANTEL was resumed at 300
mg PO Q8H with HYDROXYZINE and PREDNISONE without further
complications.
 3.4 TERATOGENICITY/EFFECTS IN PREGNANCY
 A. TERATOGENICITY
 1. U.S. Food and Drug Administration's Pregnancy Category B (Prod Info Biltricide(R),
2000).
 See Drug Consult reference: "PREGNANCY RISK CATEGORIES"
 2. Australian Drug Evaluation Committee's (ADEC) Category B1 (ADEC, 1996).
 3. Inadvertent treatment of great numbers of pregnant women with praziquantel has
resulted in no reported cases of adverse birth outcomes. Untreated schistosomiasis
can cause morbidity in pregnant women and their unborn offspring, with some
permanent sequela. Hence, in the opinion of at least one reviewer, praziquantel should
not be withheld from pregnant women with schistosomiasis (Olds, 2003).
 4. One case report of praziquantel use during pregnancy indicated no adverse effects.
At approximately 8 weeks? gestation, a 17-year-old woman began a course of
praziquantel 1050 mg 3 times daily for 21 days. She delivered a normal 2.5-kg girl at
term. Anemia was detected, but no abnormalities or malformations were noted. The
placenta appeared normal. However, because of limited data, the authors recommend
that praziquantel not be used during pregnancy unless the parasite is causing clinical
illness or public health problems (Briggs et al, 1999).
 B. EFFECTS IN PREGNANCY
 1. Mothers should not nurse on the day of PRAZIQUANTEL treatment nor during the
subsequent 72 hours. Praziquantel is present in the milk of nursing women at a
concentration approximately 25% of the concentration in maternal serum (Prod Info
Biltricide(R), 2000).
 3.5 DRUG INTERACTIONS
 3.5.1 DRUG-DRUG COMBINATIONS
 A. ALBENDAZOLE
 1. Summary: Coadministration of praziquantel and albendazole may increase
the mean maximum plasma concentration and area under the plasma
concentration-time curve (AUC) of albendazole sulfoxide (Prod Info
Albenza(R), 1996).
 2. Adverse Effect: an increased risk of albendazole adverse effects
 3. Clinical Management: Monitor patients for excessive albendazole adverse
effects (nausea, vomiting, dizziness, and abnormal liver function tests).
 4. Severity: minor
 5. Onset: delayed
 6. Documentation: fair
 7. Probable Mechanism: unknown
 8. Literature Reports:
 a. A study in 10 healthy volunteers demonstrated a mean increase of
50% in mean maximum plasma concentration and AUC of
albendazole sulfoxide when praziquantel was administered
concurrently. The pharmacokinetics of praziquantel did not change
following coadministration with albendazole and, mean Tmax and
mean plasma elimination half life of albendazole (400 mg) remained
the same (Prod Info Albenza(R), 2001).
 B. CARBAMAZEPINE
 1. Summary: A controlled study demonstrated that carbamazepine reduced
the AUC of praziquantel by 90% and the peak plasma level by 92%
(Bittencourt et al, 1992). Phenytoin also significantly reduced praziquantel
AUC and peak plasma concentration in the same study. Because seizure
disorders commonly accompany neurocysticercosis, combined therapy with
these agents may frequently be necessary. Cimetidine (an enzyme inhibitor)
has been successfully employed in one patient to counteract the enzyme
induction caused by phenytoin and phenobarbital (Dachman et al, 1994),
however these results have not been confirmed by controlled prospective
study.
 2. Adverse Effect: decreased praziquantel effectiveness
 3. Clinical Management: If concomitant use is necessary, an increased dose of
praziquantel may be required to be clinically effective.
 4. Severity: moderate
 5. Onset: delayed
 6. Documentation: fair
 7. Probable Mechanism: increased praziquantel metabolism
 C. CHLOROQUINE
 1. Summary: Chloroquine has been shown to decrease the bioavailability and
the maximum serum concentration of praziquantel in humans. A large amount
of interindividual variation did occur in this study, possibly because
praziquantel undergoes extensive first-pass metabolism. Dose increases of
praziquantel may be necessary in patients receiving chloroquine
(Masimirembwa et al, 1994).
 2. Adverse Effect: decreased praziquantel bioavailability
 3. Clinical Management: Dose increases of praziquantel should be considered
in patients receiving chloroquine, especially if the patient does not respond to
initial treatment with praziquantel.
 4. Severity: moderate
 5. Onset: rapid
 6. Documentation: poor
 7. Probable Mechanism: unknown
 8. Literature Reports:
 a. Because of the possibility of dual infections with malaria and
schistosomiasis, the effect of chloroquine on the pharmacokinetics of
praziquantel were studied in eight healthy male volunteers. Each
participant received an oral dose of praziquantel 40 mg/kg alone and
in combination with chloroquine 600 mg. Mean maximum
concentrations (Cmax) of praziquantel alone were 2.13 mcg/mL and
decreased to 0.88 mcg/mL in the presence of chloroquine. Area
under the concentration-time curve (AUC) of praziquantel also
significantly decreased from 11.75 mcg/h/mL to 4.17 mcg/h/mL when
given with chloroquine. However, one of the eight volunteers did not
have any significant pharmacokinetic alterations, suggesting that a
large interindividual variation exists. This has been explained by the
wide variation in the metabolism of praziquantel, which undergoes
extensive first-pass metabolism. Chloroquine may decrease the
curative rate of praziquantel, especially in individuals who appear to
metabolize praziquantel more quickly than others. Clinicians should
be aware that patients also receiving chloroquine may need
increased praziquantel doses (Masimirembwa et al, 1994).
 D. CIMETIDINE
 1. Summary: Significant increases in praziquantel AUC (300%), peak plasma
concentration (136%), and half-life (90%) were reported in a patient receiving
concurrent cimetidine 400 mg four times daily and combined anticonvulsant
therapy (Dachman et al, 1994). Because baseline therapy in this patient
included phenytoin and phenobarbital (enzyme inducers which increase
metabolism of praziquantel), cimetidine (an enzyme inhibitor) was being used
in hope of improving the praziquantel response. The resulting praziquantel
AUC during treatment with all four drugs approximated that reported for
praziquantel alone. The extent to which cimetidine might elevate praziquantel
concentrations without the presence of enzyme inducers and cause clinical
toxicity is not known, but this should be considered during concurrent use.
 2. Adverse Effect: increased praziquantel concentrations
 3. Clinical Management: Monitor for signs of praziquantel toxicity (eg,
drowsiness, dizziness, nausea & vomiting) and adjust the dose accordingly. If
concurrent use cannot be avoided, select another H2-antagonist (eg,
ranitidine or famotidine) that has less potential to alter drug metabolism.
 4. Severity: minor
 5. Onset: delayed
 6. Documentation: poor
 7. Probable Mechanism: decreased praziquantel metabolism
 E. DEXAMETHASONE
 1. Summary: Concomitant administration of praziquantel and dexamethasone
has been reported to result in significant reductions in praziquantel serum
concentrations in patients with neurocysticercosis (Vazquez et al, 1987).
Combined therapy in eight patients resulted in 50% reductions in praziquantel
serum concentrations as compared to levels achieved when praziquantel was
administered alone. Because the therapeutic levels of praziquantel have not
been clearly defined, it is not possible to evaluate the effect of this interaction
on therapeutic response. It is suggested that dexamethasone be avoided with
praziquantel therapy as preventative treatment in these patients.
Dexamethasone should be reserved for transient therapy of adverse
inflammatory reactions.
 2. Severity: not specified
 3. Onset: not specified
 4. Documentation: poor
 F. ETHINYL ESTRADIOL
 1. Severity: none
 2. Onset: not specified
 3. Documentation: poor
 4. Literature Reports:
 a. Concomitant administration of praziquantel or metrifonate with oral
contraceptives (Ovral(R)) was reported to result in no significant effect
on plasma hormone concentrations in healthy volunteers (El-Raghy et
al, 1986).
 G. ETONOGESTREL
 1. Severity: none
 2. Onset: not specified
 3. Documentation: poor
 4. Literature Reports:
 a. Concomitant administration of praziquantel or metrifonate with oral
contraceptives (Ovral(R)) was reported to result in no significant effect
on plasma hormone concentrations in healthy volunteers (El-Raghy et
al, 1986).
 H. FOSPHENYTOIN
 1. Summary: Fosphenytoin is a prodrug of phenytoin and the same interactions
that occur with phenytoin are expected to occur with fosphenytoin (Prod Info
Cerebyx(R), 1999). A controlled study demonstrated that phenytoin reduced
the area under the concentration-time curve (AUC) of praziquantel by 74%
and the peak plasma level by 76% (Bittencourt et al, 1992). Carbamazepine
also significantly reduced praziquantel AUC and peak plasma concentration in
the same study. Because seizure disorders commonly accompany
neurocysticercosis, combined therapy with these agents may frequently be
necessary. Cimetidine (an enzyme inhibitor) has been successfully employed
in one patient to counteract the enzyme induction caused by phenytoin and
phenobarbital (Dachman et al, 1994), however these results have not been
confirmed by controlled prospective study.
 2. Adverse Effect: decreased praziquantel effectiveness
 3. Clinical Management: If concomitant use is necessary, an increased dose of
praziquantel may be required to be clinically effective.
 4. Severity: moderate
 5. Onset: delayed
 6. Documentation: fair
 7. Probable Mechanism: increased praziquantel metabolism
 I. MESTRANOL
 1. Severity: none
 2. Onset: not specified
 3. Documentation: poor
 4. Literature Reports:
 a. Concomitant administration of praziquantel or metrifonate with oral
contraceptives (Ovral(R)) was reported to result in no significant effect
on plasma hormone concentrations in healthy volunteers (El-Raghy et
al, 1986).
 J. NORETHINDRONE




1. Severity: none
2. Onset: not specified
3. Documentation: poor
4. Literature Reports:
 a. Concomitant administration of praziquantel or metrifonate with oral
contraceptives (Ovral(R)) was reported to result in no significant effect
on plasma hormone concentrations in healthy volunteers (El-Raghy et
al, 1986).
 K. NORGESTREL
 1. Severity: none
 2. Onset: not specified
 3. Documentation: poor
 4. Literature Reports:
 a. Concomitant administration of praziquantel or metrifonate with oral
contraceptives (Ovral(R)) was reported to result in no significant effect
on plasma hormone concentrations in healthy volunteers (El-Raghy et
al, 1986).
 L. PHENYTOIN
 1. Summary: A controlled study demonstrated that phenytoin reduced the area
under the concentration-time curve (AUC) of praziquantel by 74% and the
peak plasma level by 76% (Bittencourt et al, 1992). Carbamazepine also
significantly reduced praziquantel AUC and peak plasma concentration in the
same study. Because seizure disorders commonly accompany
neurocysticercosis, combined therapy with these agents may frequently be
necessary. Cimetidine (an enzyme inhibitor) has been successfully employed
in one patient to counteract the enzyme induction caused by phenytoin and
phenobarbital (Dachman et al, 1994), however these results have not been
confirmed by controlled prospective study.
 2. Adverse Effect: decreased praziquantel effectiveness
 3. Clinical Management: If concomitant use is necessary, an increased dose of
praziquantel may be required to be clinically effective.
 4. Severity: moderate
 5. Onset: delayed
 6. Documentation: fair
 7. Probable Mechanism: increased praziquantel metabolism
 3.5.3 DRUG-LAB MODIFICATIONS
 A. No alterations in laboratory tests were observed in several double-blind studies with
healthy volunteers and infected patients (Wegner, 1984). The specific tests were not
defined.
4.0 CLINICAL APPLICATIONS
 4.3 PLACE IN THERAPY
 A. PRAZIQUANTEL is an effective anthelmintic agent which is considered the drug of choice in
the treatment of all species of schistosomes that infect man (Anon, 1988). PRAZIQUANTEL is
also an agent of first choice for treating cestode (tapeworm), trematode (fluke), and liver fluke
(Clonorchis sinensis/Opisthorchis viverrini) infections (Anon, 1988; Gilman et al, 1985; Prod Info
Biltricide(R), 2000).
 B. NICLOSAMIDE is considered an alternative to PRAZIQUANTEL for some tapeworm and fluke
infections; however, comparative trials are needed. PRAZIQUANTEL belongs on hospital
formularies for the treatment of schistosomiasis and cestode and trematode infections.
 4.4 MECHANISM OF ACTION/PHARMACOLOGY
 A. MECHANISM OF ACTION
 1. PRAZIQUANTEL is an pyrazinoisoquinoline derivative which is effective in the
treatment of schistosomiasis as well as infections caused by other flukes (trematodes
and cestodes). PRAZIQUANTEL is rapidly taken up by the parasites which are unable
to transform it metabolically. It appears to cause a rapid muscular contraction in the
schistosomes by altering the permeability of the plasma membrane to calcium ions.
This results in loss of intracellular calcium which activates the contractile process and
causes the worm to lose anchorage on blood vessels (Pax et al, 1978; Anon, 1993).
Vacuolization and disintegration of the tegument follows (Andrews, 1981). A
considerable disturbance in glucose metabolism, with depletion of lactase and alanine,
has been observed in the parasites (Wegner, 1984).
 2. PRAZIQUANTEL is active against both larval and adult tapeworms. It is effective in
all forms of schistosomiasis, both in the acute stage and in patients with extensive
hepatosplenic involvement. Taenia saginata, T solium, Hymenolepis nana, and
Diphyllobothrium latum have been eliminated (Schantz, 1996; Conlon & Ellis, 1985;
Anon, 1993). Trematodes pathogenic to man and susceptible to PRAZIQUANTEL
include: Schistosoma haematobium, S intercalatum, S japonicum, S mansoni, S
mattheei, S mekongi, Clonorchis sinensis, Opisthorchis viverrini, O felineus,
Paragonimus westermani, P heterotremus, P africanus, P uterobilateralis and
Paragonimus spp in Ecuador. Information on efficacy in infections with Heterophyes,
Clonorchis guayaquilensis and Fasciola hepatica is still limited (Wegner, 1984).
 B. REVIEW ARTICLES
 1. A review of the pharmacology, efficacy, and toxicity of PRAZIQUANTEL is presented
(King & Mahmoud, 1989).
 2. One author has provided a comprehensive review of the mechanism of the antischistosomal activity of PRAZIQUANTEL (Andrews, 1985).
 3. A review of tapeworm epidemiology, morphology, and clinical pathology is
presented (Schantz, 1996), as well as a comprehensive review of schistosomiasis in
particular (Ross et al, 2002).
 4. A review of neurocysticercosis and its treatment protocols, including praziquantel,
has been published (White, 1997).
 4.5 THERAPEUTIC USES
 A. CLONORCHIASIS/OPISTHORCHIASIS
FDA Labeled Indication
 1. OVERVIEW:
FDA APPROVAL: Adult, yes; pediatric, yes (4 years
and
older)
EFFICACY: Adult, effective; pediatric, effective
DOCUMENTATION: Adult, excellent; pediatric, good
 2. SUMMARY:
- PRAZIQUANTEL has produced
Clonorchis/Opisthorchis
(LIVER FLUKES) cure rates of 76% to 100%
- Various dosing regimens have been beneficial,
including 75 to 90 milligrams/kilogram (mg/kg)
in
3 divided doses for 1 to 2 days OR 40 to 50
mg/kg
as a single dose
- Repeat PRAZIQUANTEL dosing has raised the cure
rates
 3. ADULT:




 a. PRAZIQUANTEL is indicated for the treatment of Clonorchis
Sinensis/Opisthorchis Viverrini (approval of this indication was based on
studies in which the two species were not differentiated). Cure rates from a
single treatment course of 75 to 90 milligrams/kilogram (mg/kg) for one day in
three divided doses range from 76% to 100%. In some patients, a second
course may be necessary for complete cure (Pungpak et al, 1997; Mandell et
al, 1990; Yangco et al, 1987; O'Keefe & Edgett, 1986; Jong et al, 1985; Rim et
al, 1981). The recommended dose for clonorchiasis is 75 mg/kg given in 3
divided doses for 1 day (Prod Info Biltricide(R), 1995).
 b. A single dose of PRAZIQUANTEL (40 mg/kg) for the treatment of
Opisthorchis viverrini showed a 98% cure rate in a community study in eastern
Thailand (n=579) (Pungpak et al, 1997). Patients had mild to moderate severity
liver fluke infection.
c. In 8 trials involving 584 patients with Opisthorchis viverrini, 100% cure rates were
associated with the following PRAZIQUANTEL dosage regimens: 50 mg/kg every day X
1 day and 25 mg/kg 3 times a day X 2 days (Wegner, 1984).
d. Thirty age-matched southeast Asian refugees infected with Clonorchis
sinensis/Opisthorchis viverrini were enrolled in a double-blind, placebo controlled trial
to evaluate the efficacy and safety of PRAZIQUANTEL therapy (25 mg/kg every 4 hours
X 3 doses). Nonresponders from the placebo group were treated with PRAZIQUANTEL.
Of the 22 who received PRAZIQUANTEL (13 from PRAZIQUANTEL group and 9 from
placebo group), seventeen (77%) were cured after 1 treatment course and the
remaining 5 were cured after 2 treatment courses. Common side effects included
dizziness, nausea, malaise, and headache, but these were mild and lasted no longer
than 48 hours (O'Keefe & Edgett, 1986).
e. In 1 trial involving 5 patients with Opisthorchis felineus infections, a 100% cure rate
was achieved with PRAZIQUANTEL 25 milligrams/kilogram 3 times a day X 1 day
(Wegner, 1984).
f. Sixty-three patients with known C sinensis infection received PRAZIQUANTEL in a
single blind study. Twenty-eight patients received 40 mg/kg in a single dose on 1 day.
Thirty-five patients received 3 doses of 25 mg/kg on a single day. Thirty of 35 who
received 3 doses of 25 mg/kg on a single day were parasitologically cured completely
60 days after therapy. In 4 of 24 patients with moderate infection and 1 of 7 with heavy
infection a very small number of eggs was detected at 1 or 2-month follow-up exam.
These patients were treated again with the same dosage and were completely cured
60 days after the second treatment. Seven of the 28 patients who received 40
milligrams/kilogram were cured 60 days after therapy. The overall egg reduction rate
was 95.5%, however, the 21 uncured patients received an additional single dose of 40
milligrams/kilogram (mg/kg) and 7 of these 21 were cured. The 14 patients who
remained uncured showed egg reduction rates in excess of 90%. Few adverse effects
were observed (Rim et al, 1981).
 g. One study demonstrated a 91% cure rate in 22 patients with
Clonorchiasis/Opisthorchis infections after receiving PRAZIQUANTEL 90
milligrams/kilogram divided into 3 equal doses (one-day therapy) (Horstmann et al,
1981).
 B. CYSTICERCOSIS
 1. OVERVIEW:


FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective;
pediatric,
possibly effective
DOCUMENTATION: Adult, good; pediatric,
good
 2. SUMMARY:
- PRAZIQUANTEL is effective treatment
of
cysticercosis and neurocysticercosis
in adults and
children, although some forms of the
disease do not
respond to PRAZIQUANTEL
- Corticosteroids reduce the
inflammatory response to
treatment
 3. ADULT:
 a. The recommended praziquantel dosage for
neurocysticercosis is 50 mg/kg/day orally for 14 to 15 days.
Praziquantel therapy is recommended for those with: (1)
active cerebral cysticercosis with cysts in the brain
parenchyma or subarachnoid space, (2) cysts in brain
parenchyma, subarachnoid space, and ventricular system
(although these patients might need surgery later), (3) miliary
cysticercosis, when many cysts are likely to be too small for
detection by computerized tomography (CT) scanning
(Webber, 1994; Nash & Neva, 1984).
 b. For NEUROCYSTICERCOSIS, an alternative dosing
regimen has been suggested which is designed to take
advantage of the pharmacokinetics of the drug. The regimen
is a 1-day course including 3 oral doses of 25
milligrams/kilogram at 2-hour intervals, increasing the time
the parasite is exposed to high drug concentrations. The
results appeared to attain similar cysticidal effects to longer
courses. Advantages are greater compliance and lower cost
(Sotelo & Jung, 1998).
 c. Fever, headache, nausea, vomiting, meningismus, and
increased intracranial pressure are associated with
PRAZIQUANTEL therapy, suggesting an inflammatory
response induced by destruction of cysts. Corticosteroid
administration (prednisone 30 to 40 milligrams (mg)/day or
dexamethasone 12 to 16 mg/day) is strongly recommended
to reduce these symptoms. Some forms of the disease, such
as intraventricular cysticercosis, do not respond well to
praziquantel and surgical intervention is required. In many
cases, the infection has a fairly benign course (Webbe,
1994). Some clinicians have questioned the need and
efficacy of PRAZIQUANTEL in the treatment of
intraparenchymal neurocysticercosis because the disease is
self-limiting and spontaneous resolutions have occurred in
children with supportive treatment alone (Moodley & Mossa,
1989). In children, this disease is often benign and selflimiting with epilepsy as the major problem. In adults,
however, the course is more frequently chronic and severe,
and PRAZIQUANTEL greatly improves the prognosis in most
of the these patients (Sotelo, 1989).
 d. Six patients with CHRONIC CYSTICERCAL MENINGITIS, a
pernicious form of neurocysticercosis, were treated with 3 to
6-month courses of PRAZIQUANTEL, corticosteroids, and
ventriculoperitoneal shunting. Medical treatment with
PRAZIQUANTEL was unsuccessful in all cases and no
improvement was observed either clinically or in the
cerebrospinal fluid (CSF). The most common clinical
sequelae were blindness due to optic atrophy, dementia, gait
ataxia, and urinary incontinence. Several authors have
proposed that chronic cysticercal meningitis may be caused
by a specific form of neurocysticercosis, Cysticercosis
racemosis which responds poorly to treatment. This is in
contrast to parenchymal neurocysticercosis, caused by
Cysticercosis cellulosae, which responds quite well to
PRAZIQUANTEL (Joubert, 1990). Two reports (deGhetaldi et
al, 1984; Ciferri, 1984) emphasize the importance of the
simultaneous administration of corticosteroids and
PRAZIQUANTEL in patients with cysticercosis of the brain
parenchyma. Life-threatening inflammatory responses
induced by the destruction of parasites with PRAZIQUANTEL
can be diminished by the use of corticosteroids.
 e. One study evaluated PRAZIQUANTEL therapy (50
milligrams/kilogram orally daily for 15 days) in the treatment
of active NEUROCYSTICERCOSIS in 35 patients, with followup for 1 year (Sotelo et al, 1985). Ninety-one percent of
patients with parenchymal cysts improved with treatment,
based upon CT and CSF analysis; 47% of patients with
chronic arachnoiditis experienced remission. Similar results
were found by others (LeBlanc et al, 1986).
 4. PEDIATRIC:
 a. Practitioners treated 6 PEDIATRIC PATIENTS diagnosed
with neurocysticercosis with a 2-week course of
PRAZIQUANTEL, 50 milligrams (mg)/kilogram (kg)/day in 3
divided doses and prednisone, 2 mg/kg/day (Kalra et al,
1987). All 6 patients showed clinical improvement.
Symptoms disappeared and no recurrence was observed
during a follow-up of 18 +/- 3 months. Headache, vomiting
and seizures were observed in 2 cases following
PRAZIQUANTEL therapy. These symptoms were controlled
with ACETAZOLAMIDE with or without MANNITOL. CT scans
reverted to normal in 5 of 6 patients 6 to 12 weeks after
therapy. Similar results were found by others (Norman &
Kapadia, 1986).
 C. DIPHYLLOBOTHRIUM INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Effective in treating
diphyllobothrium infections
 3. ADULT:
 a. Praziquantel was effective in treating
DIPHYLLOBOTHRIUM NIHONKAIENSE infection in 3
Japanese patients. The patients received a single dose of 7
to 25 milligrams/kilogram of praziquantel. All patients
expelled the tapeworm with scolex 2 to 5 hours after taking
praziquantel and no side effects were noted (Ohnishi &
Murata, 1993).
 b. A single dose of praziquantel 5 to 10 milligrams/kilogram
is efficacious (greater than 95% rate of cure) in the treatment
of diphyllobothriasis (Schantz, 1996).
 D. ECHINOCOCCUS GRANULOSUS INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Used as adjunct to surgery for
hydatid cysts
- Drug activity against the larval
stages of the dog
tapeworm, Echinococcus granulosus
 3. ADULT:
 a. PRAZIQUANTEL failed to kill the germinal layer of
HYDATID CYSTS from which the larvae develop, despite
killing the protoscolices in the cyst fluid (Conlon & Ellis,
1985). Other animal studies have shown similar lack of
efficacy of PRAZIQUANTEL in the treatment of hydatid
disease (Wegner, 1984). PRAZIQUANTEL should not be
used as the sole treatment of inoperable hydatid cysts, but
may prove to be of value as an adjunct to surgical excision if
it kills the germinal matter that is spilled from the cysts at
operation and is unprotected by membranes.
 E. FASCIOLOPSIS BUSKI INFECTION
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, poor
 2. SUMMARY:
- PRAZIQUANTEL dosed as 75
milligrams/kilogram/day in
3 divided doses for 1 day of therapy
is considered
the drug of choice for the treatment
of Fasciolopsis
buski infections (Anon, 1991)
 F. HYMENOLEPIS NANA INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Effective treatment for Hymenolepis
infections
 3. PEDIATRIC:
 a. PRAZIQUANTEL was effective in treating H nana infection
TAPEWORM INFECTION in 155 children. Sixty-five children
received 25 milligrams/kilogram in a single dose. Sixty-five
children received 15 milligrams/kilogram and 25 received 10
milligrams/kilogram. Parasitological cure as determined by
microscopic stool examination on days 5 to 7, 10 to 20, and
15 to 17 after dosing demonstrated cure rates in 64 (98.5%)
of those children receiving 25 milligrams/kilogram, in 61 of 65
(93.8%) given 15 milligrams/kilogram and 19 of 25 (76%) of
those given 10 milligrams/kilogram. The authors reported no
side effects associated with therapy (Schenone, 1980).
 G. METAGONIMUS YOKOGAWAI INFECTION
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, effective
DOCUMENTATION: Adult, good
 2. SUMMARY:
- PRAZIQUANTEL dosed as 75
milligrams/kilogram/day in
3 divided doses for 1 day of therapy
is considered
the drug of choice for the treatment
of Metagonimus
yokogawai (INTESTINAL FLUKES)
infections
(Anon, 1991)
 H. NANOPHYETIASIS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, fair
 2. SUMMARY:
- Limited data suggest that
PRAZIQUANTEL may have
efficacy against nanophyetiasis
 3. ADULT:
 a. Nanophyetiasis is a newly described zoonotic disease of
the coastal US Pacific Northwest and is acquired by
ingestion of raw, home-smoked, or incompletely cooked fish,
from coastal streams and rivers. Nine patients with positive
stool tests for Nanophyetus salmincola were treated with
PRAZIQUATEL 60 milligrams/kilogram for 1 day, in 3 divided
doses. Prior to treatment, five patients presented with
histories of gastrointestinal complaints and five had
eosinophilia. Follow-up stool exams were performed 2 to 12
weeks after treatment, and in all cases, were negative for
eggs of Nanophyetus. Seven of nine patients noted prompt
resolution of symptoms following therapy. Symptoms
persisted in 2 patients, who subsequently were thought to
have had pre-existing gastrointestinal tract problems. No
adverse drug reactions were reported. Nanophyetiasis is an
underreported zoonotic disease that may be the most
commonly encountered trematodiasis endemic to North
America. The use of PRAZIQUANTEL in its treatment
appears to be efficacious (Fritsche et al, 1989).
 I. PARAGONIMIASIS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, effective; pediatric,
effective
DOCUMENTATION: Adult, fair; pediatric,
fair
 2. SUMMARY:
- Paragonimiasis is caused by the lung
fluke
Paragonimus westermani
- PRAZIQUANTEL is the drug of choice
to treat adult
and pediatric paragonimiasis
- PRAZIQUANTEL has a cure rate of
approximately 90% or
greater
 3. ADULT:
 a. Paragonimiasis is endemic in areas of the world where
freshwater crab, crayfish, or shrimp are eaten raw, pickled,
or undercooked. The disease is secondary to the Oriental
lung fluke PARAGONIMUS WESTERMANI. One study
reported an 85.7% cure rate in 7 patients at 3 months
following an oral course of PRAZIQUANTEL therapy (75
milligrams/kilogram/day orally for 2 days) (Johnson et al,
1985). A 100% cure rate was observed at 4 months. The
recommended dose for PARAGONIMIASIS is 75
milligrams/kilogram in 3 divided doses for 2 days (Mandell et
al, 1990).
 b. In 3 trials involving 83 patients with P westermani
infections, a 100% cure rate was achieved with
PRAZIQUANTEL 25 milligrams/kilogram three times a day for
3 days. In 1 trial of 13 patients with P heterotremus infection,
a cure rate of 76.9% was achieved with 25
milligrams/kilogram three times a day for 1 day. In 6 patients
with P uterobilateralis infection, and 19 patients with
Paragonimus spp in Ecuador, 100% cure rates were
achieved with PRAZIQUANTEL 25 milligrams/kilogram three
times a day for 2 days. With regard to susceptibility,
Paragonimus spp can be placed between S japonicum, C
sinensis, and O viverrini on the one hand, and F hepatica on
the other. Susceptibility to PRAZIQUANTEL appears to
depend on the ease with which the drug can penetrate into
the interior of the parasite. The thickness of tegument
increases remarkably in the order in which these parasites
are mentioned. This explains why a longer exposure to the
drug is necessary for Paragonimiasis (Wegner, 1984).
 c. Practitioners treated 6 patients with documented P
uterobilateralis (lung fluke) with PRAZIQUANTEL 20
milligrams/kilogram 3 times a day for 2 days (Monson et al,
1983). No side effects were noted in any of the patients.
Within 48 hours of treatment hemoptysis stopped and cough
completely disappeared within the next days. Radiographic
changes showed improvement as early as 2 weeks after
treatment and complete resolution as early as 5 months after
treatment. Long term follow-up at 5 to 8 months showed
complete resolution.
 4. PEDIATRIC:
 a. A case report describes pleural paragonimiasis in an 11.5year-old Laotian boy who was successfully treated with
PRAZIQUANTEL (Heath & Marshall, 1997). Ultrasound
examination of the chest showed a massive left pleural
effusion enclosing mobile debris. On thoracotomy, thick fluid,
proteinacious material, and a fluke (P westermani) were
found. The boy was administered a 3-day course of
praziquantel and discharged.
 J. SCHISTOSOMIASIS
FDA Labeled Indication
 1. OVERVIEW:
FDA APPROVAL: Adult, yes; pediatric,
yes (4 years and
older)
EFFICACY: Adult, effective; pediatric,
effective
DOCUMENTATION: Adult, excellent;
pediatric,
excellent
 2. SUMMARY:
- Praziquantel is considered mainstay
of treatment
and critical for community-based
control programs
-- Cure rates produced by
PRAZIQUANTEL range from
75% to 95%
-- Same effectiveness in HIV-infected
patients
-- Not appropriate for prophylaxis
-- Resistance may be emerging
(Ross et al, 2002)
- Dosing regimens include 20
milligrams/kilogram
(mg/kg) three times a day for 1 to 3
days OR 40 to
60 mg/kg in 2 divided doses for 1
day OR 40 to
50 mg/kg as a single dose
- Higher single doses have resulted in
greater adverse
effects
- A case of schistosomiasis resistant
to 3 courses of
praziquantel treatment was reported
 3. ADULT:
 a. Clinical trials have shown PRAZIQUANTEL to be very
effective in the treatment of schistosomal infections.
Depending on the specific species being treated, cure rates
range from 75% to 95% following single dose or 1-day
divided dose therapy (Stelma et al, 1995; Pollner et al, 1993;
Homeida et al, 1988; Watt et al, 1986; Kardaman et al, 1983;
Coutinho et al, 1983; Oyediran et al, 1981; da Silva et al,
1981; Omer, 1981; Katz et al, 1981). For Schistosoma
mansoni or haematobium, the dose of PRAZIQUANTEL for
adults and children over 4 years (greater than 20 kg) is 40
milligrams/kilogram (mg/kg) per day divided in 2 doses for 1
day; for Schistosoma japonicum or mekongi, the dose is 60
mg/kg/day in 3 divided doses for 1 day. Doses should be
given at least 4 to 6 hours apart. Administration of a single
large dose is associated with a higher incidence of adverse
effects (Katz et al,1979).
 b. Three courses of praziquantel, separated by a year or
more, failed to cure a 26-year-old British man of
schistosomiasis, acquired during a trip to Kenya, despite the
absence of any opportunity for reinfection. A few months
after returning from Kenya, the man was asymptomatic, but
serological testing was strongly positive for schistosomiasis
(level 4). He was treated with a single dose of praziquantel
40 milligrams (mg). Eighteen months later, his serology was
more strongly positive (level 5). He was treated with another
dose of praziquantel 40 mg. In the third year, he experienced
non-specific malaise, intermittent abdominal discomfort, and
semi-solid stools. He had mild peripheral blood eosinophilia,
for which no cause (eg, Strongyloides infection or filariasis)
could be found. Stool and urine specimens were negative for
ova, cysts, and parasites, but schistosomiasis serology was
elevated (level 5). Biopsies of bowel mucosa showed
inflammation and eggs of S. mansoni. He was given a third
treatment of praziquantel 40 mg. A year later, symptoms and
laboratory tests remained the same. An alternative treatment,
oxamniquine, was unavailable in Britain, and he was
therefore treated with praziquantel 40 mg/day for 3
consecutive days. Symptoms abated and serology
normalized. At no time during treatment did the man return to
an area with endemic schistosomiasis (Lawn et al, 2003).
 c. Comparison studies of two dosages (40 mg/kg as a single
dose or 60 mg/kg in 2 divided doses) found little difference
in efficacy between the two dosing regimens; due to
practicality, the single-dose regimen was recommended for
treatment of large populations or community-wide programs,
while the 2-dose treatment was recommended for individual
treatment as the lower doses were associated with reduced
side effects (Abu-Elyazeed et al, 1997; Guisse et al, 1997). In
the former study, 1588 patients between the ages of 5 and
50 years with Schistosoma mansoni infection were enrolled in
2 Egyptian study sites, Om El-Laban and Farshout. Failure
rates were 14.5% and 4.1% for the single and 2-dose
treatments, respectively. In the latter study, 130 children in
northern Senegal were studied. No significant difference in
cure rates was found between the 1 and 2-dose regimens.
Mean egg counts were reduced by 99% in both groups.
 d. Mass PRAZIQUANTEL therapy was an effective method of
reducing the prevalence of Schistosoma haematobium in the
village of El Absi in Giza, Upper Egypt. Prevalence of
schistosomiasis at the 1-year follow-up was reduced by
83.6% from 23.1% to 3.8%. Among the infected residents,
geometric mean egg counts decreased from 12.4 to 3.1
eggs per 10 mL of urine, a four-fold decrease. At baseline,
all residents of the village were offered praziquantel (40
milligrams/kilogram as a single dose) and screened for S
haematobium ova in the urine. A month later all who had
tested positive were re-examined for schistosomiasis and retreated with praziquantel if still positive. At 1 year, all village
residents were re-examined, and findings compared with
baseline (Talaat & DeWolfe Miller, 1998).
 e. Researchers treated 352 Senegalese infected with S
mansoni, with 40 mg/kg of praziquantel (Stelma et al, 1995).
The parasitologic cure rate 12 weeks after therapy was 18%.
The frequency of egg counts with more than 1000 eggs per
gram (epg), decreased from 41% to 5%. The mean egg
count of those remaining positive was reduced by 86%. The
low cure rate may be due to intense transmission and/or
undeveloped immune responses in this recently exposed
population. The authors also demonstrated praziquantel
resistance in at least one S mansoni isolate from this area in
Senegal in the same group. Oxamniquine is a viable
treatment alternative, as strains resistant to praziquantel in
animal models respond to this drug.
 f. One report describes the effectiveness of single-dose
PRAZIQUANTEL therapy (60 milligrams/kilogram) in 9 Filipino
patients with seizures caused by cerebral S JAPONICUM
infection (Watt et al, 1986). Eight patients were cured and
discharged from the study seizure-free, without
anticonvulsants, an average of 6 months after therapy.
Another report describes a rare case of CEREBRAL
SCHISTOSOMIASIS caused by S haematobium in a 30-yearold male (Pollner et al, 1993). The patient responded to
therapy with praziquantel (20 mg/kg orally 3 times a day x 3
days), dexamethasone, and phenytoin.
 g. Researchers studied the efficacy and tolerance of
PRAZIQUANTEL in the treatment of active S MANSONI
infection in 59 patients with SYMMERS' PERIPORTAL
FIBROSIS (Homeida et al, 1988). They compared these
results with a similarly treated group of 238 patients without
liver involvement. Patients were treated with a single dose of
40 milligrams/kilogram (mg/kg) of PRAZIQUANTEL. Six
months after treatment 30 patients (51%) of the Symmers'
group and 138 (58%) of the non-Symmers' group were cured
of their infection. There was no significant difference in side
effects or the drug's anti-schistosomal activity between the 2
groups.
 h. No significant difference was observed between 3 doses
of 20 mg/kg or 1 dose of 50 mg/kg. Twenty-five of 26 (96%)
patients followed at 1 year were cured. Others reported a
78.9% cure rate following single doses of 30 mg/kg and an
86.3% cure rate following doses of 20 mg/kg twice daily at 6month follow-up (Coutinho et al, 1983). Noncured patients
showed a marked reduction in the number of eggs
eliminated in the feces.
 4. PEDIATRIC:
 a. MONOTHERAPY
 (1) One report describes the case of S
haematobium infection in a 7-year-old expatriate
boy that persisted despite multiple courses of
praziquantel therapy (Herwaldt et al, 1995). The
authors address various host and parasite factors
than can cause suboptimal response to
praziquantel. They recommend that physicians
caring for patients unresponsive to praziquantel
contact the U.S. Centers for Disease Control at (404)
488-7760 to discuss further treatment options.
 (2) Another study showed substantial improvement
of PERIPORTAL FIRBROSIS in 420 S mansoniinfected Sudanese school children seven months
after praziquantel therapy (Mohamed-Ali et al,
1991). Patients were treated at random with either
20 mg or 40 mg/kg of praziquantel. No significant
difference was found between these two groups in
reducing egg excretion or reversing periportal
fibrosis. Children younger than 11 years of age had
a higher rate of complete reversibility than older
ones. Periportal fibrosis was graded into 3 degrees
and was based on the degree of hyperechoic
periportal bands in the liver. Periportal fibrosis grade
II decreased from 22.9% to 6.7% and grade III from
5.2% to 1.6%. The percentage of patients with
hepatomegaly also decreased significantly (11.6%
to 6.9%; p=0.001).
 (3) Another study examined the impact of annual
PRAZIQUANTEL therapy (40 mg/kg as a single
dose) on Symmers' fibrosis induced by Schistosoma
mansoni (Homeida et al, 1991). Forty-eight
Sudanese villagers, having various degrees of
Symmers' fibrosis, were followed from 1986 to 1989.
Results indicated a significant improvement
between the fibrotic status of patients in 1986 and
their fibrotic status in 1989. After 3 years of therapy,
12 of 48 patients (25%) no longer had detectable
fibrosis, while 16 showed a decrease in the amount
of fibrosis in their livers. Therapeutic response was
not dependent on sex, pretreatment egg count, or
pretreatment liver or spleen size. PRAZIQUANTEL
appeared to be able to block and reverse the
disease process in Sudanese children and adults.
 (4) PRAZIQUANTEL therapy in children may
promote an acquired immune response that will
protect the individual against future episodes of
schistosomiasis (Mutapi et al, 1998). A study in 41
children (5 to 16 years of age) with Schistosoma
haematobium found that after use of praziquantel,
predominant antibody responses switched from an
IgA to an IgG1-specific response. IgG1 responses
are more commonly associated with adult immune
system reactions that show acquired resistance to
the infecting agent. The mechanism may be
alterations in cytokine concentrations related to the
release of antigens by dead or damaged
schistosomes disabled by exposure to praziquantel.
 (5) In 151 Zambian school children, 3 different
dosage regimens of PRAZIQUANTEL were tested
for efficacy against S HAEMATOBIUM. Regression
analysis indicated that a single dose of 40
milligrams/kilogram proved better than the other two
regimens (30 milligrams/kilogram as a single dose
and 20 mg/kg X 2 doses) and produced cure rates
of 98% at 3 months, 82% at 7 months, 70% at 1
year, and 58% at 2 years. The authors stated that
"failures" up to 7 months could probably be
attributed to true drug failures, whereas, treatment
failures between 7 and 24 months most probably
were associated with reinfection rather than drug
failure. Cure rates did vary inversely with the
intensity of excretal egg output (Davis et al, 1981).
 b. COMBINATION THERAPY
 (1) Simultaneous OXAMNIQUINE and
PRAZIQUANTEL in low single doses of 7.5 and 15
milligrams/kilogram, respectively, were effective in
treating school age children infected with S
MANSONI, HAEMATOBIUM, or concomitant
infection. There was a greater than 93% egg count
reduction at 1 month, 3 months, and 6 months after
treatment (Pugh & Teesdale, 1983).
 K. TAENIA INFECTIONS
 1. OVERVIEW:
FDA APPROVAL: Adult, no; pediatric, no
EFFICACY: Adult, possibly effective
DOCUMENTATION: Adult, poor
 2. SUMMARY:
- A single
10 milligrams/
kilogram
than 95% rate of
cure) in
(Schantz, 1996)
- Close to
Taenia saginata was
achieved
milligrams/
kilogram
dose of praziquantel 5 to
is efficacious (greater
the treatment of taeniasis
100% efficacy against
with doses as low as 2.5
(Pawlowski, 1991)
 4.6 COMPARATIVE EFFICACY AND EVALUATION WITH OTHER SIMILAR THERAPEUTIC AGENTS
 A. ARTEMISININ
 1. CLONORCHIASIS
 a. Praziquantel was immediately more efficacious than artemisinin in the
treatment of Clonorchis sinensis (C sinensis) infection, yet this difference was
not maintained at 5-week follow-up, in a randomized, comparative, pilot study.
Patients with confirmed presence of C sinensis eggs in stool samples received
either oral praziquantel 25 milligrams/kilogram (mg/kg) once-daily for 3 days
(n=21), or oral artemisinin 500 mg twice-daily for 5 days (n=21). Stool sample
egg counts were significantly lower after treatment with praziquantel compared
with artemisinin (p less than 0.001 at day 6, and p=0.002 at week 5). The
number of patients without detectable C sinensis eggs in follow-up stool
samples was significantly higher at 6 days post-treatment in the praziquantel
group compared with patients taking artemisinin (71% and 19%, respectively;
p=0.001). The percentage of praziquantel-group patients with egg-free stool
samples decreased to 29% by follow-up week 5, perhaps reflective of a lessthan-effective dosing regimen. Concurrent infection with Trichuris trichiura and
Ascaris lumbricoides was incidentally found in all patients treated; it is notable
that the 2 other intestinal helminths were unaffected by either treatment (Tinga
et al, 1999).
 B. ALBENDAZOLE
 1. SUMMARY
 a. ALBENDAZOLE has a higher rate of eradication of parenchymal brain cysts
compared with PRAZIQUANTEL
 b. ALBENDAZOLE and PRAZIQUANTEL have comparable safety profiles
 c. ALBENDAZOLE attains a higher concentration in cerebrospinal fluid and is
less likely to interact with seizure drugs (eg, phenytoin, carbamazepine)
 2. NEUROCYSTICERCOSIS
 a. SUMMARY: In clinical trials comparing the efficacy of ALBENDAZOLE and
PRAZIQUANTEL in the treatment of NEUROCYSTICERCOSIS, albendazole
shows equal or greater efficacy than praziquantel. Albendazole 15 to 20
milligrams/kilogram (mg/kg) daily for 21 to 30 days compared with
praziquantel 50 mg/kg/day for 14 to 21 days results in clinical improvement
rates of 76% to 88% and 50% to 73%, respectively. Concomitant steroid and
anticonvulsant therapy is usually administered (Takayanagui & Jardim, 1992;
Cruz et al, 1991; Sotelo et al, 1988). The 2 drugs have generally comparable
safety profiles. However, albendazole appears to be the drug of choice over
praziquantel due to its higher concentration in cerebrospinal fluid, greater
eradication rate in parenchymal brain cysts, lower likelihood of interactions
with anticonvulsant medications, and cost advantage (Mehta et al, 1998). The
results of some trials need to be interpreted with caution as some of them are
neither double-blinded nor randomized (Takayanaqui & Jardim, 1992).
 b. Albendazole 15 mg/kg/day orally for 1 month was reported as effective as
praziquantel 50 mg/kg/day orally for 2 weeks in the treatment of parenchymal
brain cysticercosis in a randomized study involving 25 patients. In the 10
patients assigned to albendazole, a 76% remission of lesions was observed,
with a reduction in the number of cysts in 9 cases and disappearance of all
parenchymal cysts in 6. With the 10 patients on praziquantel, a single course
induced a 73% remission of lesions, with a reduction in the number of lesions
in 9 and disappearance of all parenchymal cysts in 7. In 5 control patients who
received only anticonvulsants, steroids, and analgesics, the cystic lesions
remained unchanged (Sotelo et al, 1988).
 c. One study compared albendazole and praziquantel in the treatment of
neurocysticercosis in 100 patients (Cruz et al, 1991). Overall clinical
improvement occurred in 84% of cases treated with albendazole, compared
with 62% of those treated with praziquantel (a statistically significant
difference). Patients in both groups also received concomitant steroid therapy
during treatment. There were no significant side effects with either treatment.
 d. Researchers performed a prospective study with 59 consecutive patients
comparing the efficacy of albendazole (n=21) and praziquantel (n=22) in the
treatment of neurocysticercosis (Takayanagui & Jardim, 1992). Sixteen
patients were treated with symptomatic drugs (dexamethasone and antiseizure medications) and used as controls. Praziquantel was given at a dose
of 50 mg/kg/day for 21 days; albendazole at 20 mg/kg/day for 21 days.
Evaluation of therapeutic response consisted of cyst counts before and 6
months after the end of therapy. Both drugs were effective when compared to
the control group. Comparatively, albendazole showed more efficacy than
praziquantel in reducing the number of cysts in the CT scan (88% vs 50%),
respectively). However, the results of this study need to be interpreted with
caution as the study was neither randomized nor double-blinded. The
population samples were small and the patients in the albendazole group
were, on the average, older and had fewer cysts. The follow-up time for the
control group was also considerably shorter than the two treatment groups,
and therefore, the control group might not have reflected the natural clinical
course of neurocysticercosis.
 C. METRIFONATE
 1. SCHISTOSOMA HAEMATOBIUM INFECTIONS
 a. SUMMARY: Praziquantel is the drug of choice for
infections involving all 5 human schistosome species (S
haematobium, S mansoni, S mekongi, S japonicum, S
intercalatum). Metrifonate is an effective alternative to
praziquantel only for treatment of S haematobium infections.
Several controlled studies have demonstrated the superiority
of praziquantel (30 to 40 milligrams/kilogram/day, single
dose, or for 3 total doses given 2 weeks apart) in the
treatment of S haematobium infections, praziquantel appears
to more effectively reduce S haematobium egg count and
produce higher cure rates than metrifonate.
 b. One study compared the efficacy of praziquantel 40
milligrams (mg)/kilogram (kg), metrifonate 10 mg/kg, and
combined metrifonate 10 mg/kg and niridazole 25 mg/kg in
children from 2 Malawi schools (Pugh & Teesdale, 1983).
Praziquantel was the most effective with a greater than 97%
reduction in egg count demonstrated 6 months after
treatment. Combination niridazole and metrifonate therapy
accounted for a 92% reduction, whereas an 86% reduction
was seen for metrifonate alone. All of the treatments were
well tolerated. Similar results were reported by McMahon
(1983).
 c. Another study evaluated the relationships between
Schistosoma haematobium, hookworm, malaria, hemoglobin
level, splenomegaly, and hepatomegaly, before and 8
months after treatment with a single dose of metrifonate (10
mg/kg) or praziquantel (40 mg/kg) in 312 Kenyan school
children in an area where anemia, Schistosoma
haematobium, hookworm, and malaria infections are
endemic (Stephenson et al, 1989a). Eight months after
treatment, the prevalence of Schistosoma haematobium had
decreased from 100% to 62% in the metrifonate group, and
13% in the praziquantel group. Prevalence was 98% in the
placebo group. Moreover, a modest rise in hemoglobin (0.3
g/dL greater than placebo) occurred only in the metrifonate
group, whereas, the praziquantel group showed no change
in hemoglobin level. This effect on hemoglobin level may
have been due to the ability of metrifonate to decrease both
Schistosoma haematobium and hookworm egg counts,
whereas praziquantel has no effect on hookworm infection.
Both metrifonate and praziquantel in single dose are useful
for large scale chemotherapy where the goal is morbidity
reduction. Praziquantel is more effective in reducing S
haematobium egg counts and can be used for S mansoni,
but is much more costly than metrifonate, and does not
decrease hookworm incidence and anemia, whereas
metrifonate can. Treatment of S haematobium with either
drug, however, appears to have a beneficial effect on
hepatomegaly and splenomegaly in children. In another
study by these same authors, treatment of S. haematobium
infections with single-dose of metrifonate or praziquantel may
improve child growth in areas where protein-energy
malnutrition, and in case of metrifonate, hookworm infections
are endemic. The degree of growth improvement appears to
be equal with either drug regimen (Stephenson et al, 1989b).
 d. Kenya school children with Schistosoma haematobium
(n=2,493) were randomized to receive either metrifonate (10
mg/kg for three doses at 4-month intervals each year) or
praziquantel (40 mg/kg as a single dose each year) for a
period of one to three years. Results indicated significant
long-term suppression of S haematobium infection in this
population. The decrease in prevalence and intensity of
infection was maximal after two years, and suppression of
infection lasted for at least two years after discontinuation of
therapy. Comparison of metrifonate and praziquantel showed
greater suppression of infection and longer infection-free
intervals for some groups treated with praziquantel. Areas
not experiencing decreased transmission had the highest
initial prevalence, higher levels of adult infection, and the
least access to safe water (King et al, 1991).
 D. NIRIDAZOLE
 1. SCHISTOSOMA INFECTIONS
 a. Praziquantel 30 milligrams (mg)/kilogram (kg)
administered as a single oral dose was compared with
metrifonate 10 mg/kg given at 2-week intervals for 3 doses
and niridazole 25 mg/kg each day for 6 days in 90 patients
with Schistosoma haematobium. The evaluation of
therapeutic efficacy was made by parasitological
examination 2 and 4 months after therapy with 3 consecutive
daily urine examinations. Cure rates at 4 months were 27 of
30 (90%), 13 of 22 (59%), and 13 of 20 (65%) for
praziquantel, metrifonate, and niridazole respectively.
Reduction in egg excretion of noncured cases is 99%
(praziquantel), 98% (metrifonate) and 75% (niridazole)
(McMahon, 1983).
 b. Another study compared the efficacy of praziquantel and
niridazole in Schistosoma intercalatum (Feldmeier et al,
1981). Forty-five patients with documented schistosomiasis
were randomly divided into 2 groups. Group A (22 patients)
received praziquantel 30 mg/kg in 2 doses 4 hours apart.
Group B (23 patients) received niridazole in a daily dose of
25 mg/kg for 7 consecutive days. Patients receiving
niridazole also received 3 x 2 mg diazepam to avoid
neurotoxic side effects seen with this drug. Parasitologic
cure was to find the absence of eggs in 3 consecutive stool
examinations 6 weeks after therapy. Thirteen of 19 (68%)
patients treated with praziquantel were cured in contrast to 6
of 17 (35%) treated with niridazole. The incidence of adverse
effects was not significantly different and abdominal
discomfort, nausea, anorexia, diarrhea and vomiting were
only observed transiently.
 E. OXAMNIQUINE
 1. SCHISTOSOMA MANSONI INFECTIONS
 a. Praziquantel 60 milligrams (mg) per kilogram (kg) daily for
3 days was similarly effective as oxamniquine 10 mg/kg
twice daily for 1 day when assessed by 3 different stool
examination techniques (100% versus 90.3%, respectively).
However, rectal mucosa biopsy (oogram) at six months
showed only praziquantel to maintain a similarly high cure
rate (96%), while the cure rate for oxamniquine was reduced
by half (42%). Cure rates for a parallel placebo-control group
were 16% and 0% by stool exam or rectal biopsy methods,
respectively (Ferrari et al, 2003).
 b. Praziquantel provided significantly better relief of clinical
symptoms as well as improved efficacy in reducing egg
excretion than oxamniquine in a randomized, single-blind
comparative trial of single dose praziquantel (40
milligrams/kilogram (mg/kg)) compared to oxamniquine (15
mg/kg) or no treatment in 188 Tanzanian children with
Schistosoma mansoni (Rugemalila et al, 1984). Patients were
monitored 24 hours after treatment and at 1, 2, and 6 months
thereafter. Abdominal discomfort was reported more
commonly in the praziquantel group (71%) than in the
oxamniquine group (45%), however, the incidence of
somnolence, diarrhea, nausea and vomiting were about the
same for both groups. All side effects were mild and resolved
within 1 to 2 hours. Alleviation of disease symptoms was
significantly greater after 6 months in the praziquantel group
(63%) compared to the oxamniquine (32%) and
nontreatment groups (24%).
 c. Among patients who failed treatment with either
praziquantel or oxamniquine, use of the alternative agent
was highly effective resulting in negative stools in 11 of 12
cases examined 1 month after the second round of therapy.
Two hundred children were originally treated with either
oxamniquine 20 milligrams/kilogram (mg/kg) (n=90) or
praziquantel 60 mg/kg (n=110). Cure rates averaging about
85%, were similar in both groups. Children still passing eggs
two to three months after therapy were retreated with the
alternative drug. The authors suggested that patients be
treated with one drug and therapeutic failures with another to
minimize the risk of developing drug resistance (Katz et al,
1991).
 F. TRICLABENDAZOLE
 1. PARAGONIMIASIS - HUMAN
 a. In an open trial of 62 adult patients with human pulmonary
paragonimiasis due to P. mexicanus, oral triclabendazole
was superior to oral praziquantel. The patients were
randomly administered 1 of 4 regimens: triclabendazole 5
milligrams/kilogram (mg/kg) body weight daily for 3 days;
triclabendazole 10 mg/kg body weight twice daily for 1 day;
single dose of triclabendazole 10 mg/kg body weight; or
praziquantel 25 mg/kg 3 times daily for 3 days. All patients
were observed in the hospital for the first 7 days after
treatment, and then as outpatients 30, 90, and 365 days after
treatment. All hematologic, biochemical, and urine analyses
were within normal limits at all post-dose follow-up sessions
for all regimens. Adverse effects for the first 7 days were
fewer and less severe with triclabendazole than with
praziquantel, with the triclabendazole 10 mg/kg twice daily
regimen being best tolerated. Treatment efficacy was
determined by monitoring clinical response to treatment,
sputum volume and color, egg count in sputum, and time
required for patients to cease excreting Paragonimus eggs in
sputum and stool samples. Triclabendazole was superior to
praziquantel for clinical response, clearance rate of eggs
from the sputum, and amount of time before sputum volume
decreased. All patients were cleared of infection at 90 days
after treatment except for 2 of 16 patients who received the
low single-dose regimen of triclabendazole. Treatment was
repeated in these patients and no eggs were found in the
sputum of any of the patients at 365 days. Larger clinical
trials are needed in various geographic areas to determine
the most efficient dose of triclabendazole for the treatment of
human paragonimiasis (Calvopina et al, 1998).