By Satarkulova A.M.
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Human is the primary host for most helminthic
infections.
Most worms produce eggs and larva.
These pass out of human body and infect secondary
host.
Immature forms invade humans via skin or GIT.
1. Worms live in hosts alimentary canal.
2. Worms or larvae live in other tissues of
host body like: muscles , viscera ,
menninges , lungs, subcutaneous tissues.
3
Ascaris lumbricoids ( common round worm)
Filariasis
Hookworm
Tapeworm
Whipworm
Cysticercosis
Elephantiasis
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goal of anthelmintic therapy is to
eradicate the parasite completely.
Anthelmintics should be used only when
clearly indicated (laboratory
documentation of parasitic infestation).
Monitoring of safety and efficacy is
required.
Ascariasis
Fillariasis
Ancylostomiasis
Trichocephaliasis
Enterobiasis
Trichinosis
Strongyliasis
Toxocariasis
Trichuriasis
Pyrantel
Mebendazole
Thiabendazole
Albendazole
Flubendazole
Ivermectine
Diethylcarbamazine
Opisthorchiasis
Clonorchiasis
Praziquantel
Triclabendazole
Paragonomiasis
Bithionol
Fascioliasis
Oxamniquine
Schistosomiasis
Taeniasis
Taeniarhynchiasis
Praziquantel
Diphillobotriasis
Niclosamide
Hymenolepiasis
Echinococcosis
Albendazole
May act by causing :
 paralysis of the worm.
 damaging the worm leading to partial
digestion or rejection by immune
mechanisms.
 interfere with the metabolism of the
worm.
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Broad spectrum.
MOA: Inhibits microtubule synthesis that
irreversibly impairs glucose uptake , intestinal
parasites are immobilized and die slowly.
Given orally , absorption ↑ with a fatty meal.
Metabolized in the liver to the active metabolite
albendazole sulfoxide.
Plasma half life 8-12 hours.
Albendazole sulfoxide is mostly protein bound
distributes well to tissues and enters bile, CSF .
Metabolites are excreted in urine.
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Used on empty stomach when used against
intraluminal parasites, but with a fatty meal
when used against tissue parasites.
In ascariasis , trichuriasis , hookworm, pin worm
infections.
Hydatid diseases .
Neurocysticercosis.
Other infections: drug of choice in cutaneous
and visceral larva migrans , intestinal
capillariasis .
In short term(1-3 days): No adverse effects.
In long term use :
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abdominal pain,
headache, fever,
fatigue, alopecia,
increased liver enzymes,
pancytopenia.
Contraindication:
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pregnancy,
hypersensitive peoples,
children under 2 y. (may cause convulsion)
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Synthetic benzimidazole.
Wide spectrum and safer than albendazole.
MOA, Clinical uses, Adverse effects, Contraindication
as albendazole.
Converted to inactive metabolites .
Half- life 2-6 hrs.
MOA as other benzimidazole.
 Half- life of 1-2 hrs.
 Metabolized in liver and 90% is excreted in urine.
 Can also absorbed through skin.
 Clinical uses:
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Strongyloidal infections.
 In cutaneous larva migrans .
 Adverse effects: Pruritus ,headache, drowsiness ,
irreversible liver failure.
 Contraindication: children , pregnancy, hepatic
and renal diseases.
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Broad spectrum.
Poorly absorbed orally.
Excreted unchanged in the feces.
MOA: Neuromuscular blocking drug leads to paralizes of
worms.
Clinical uses:
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Pin worm.
Ascariasis .
Hookworm.
Adverse effects: mild GI disturbance, drowsiness ,
headache ,insomnia, rash , fever.
Contraindications
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Pregnancy.
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Children under 2 y. of age.
Only for the treatment of ascariasis cure rate 90%
for 2 days treatment.
 Readily absorbed orally.
 Excreted mostly unchanged in urine.
 MOA: Causes paralysis of ascaris by blocking
acetylcholine at myoneural junction , the live worms
expelled by normal peristalsis.
 Adverse effects: GI disturbance, neurotoxicity ,
allergic reactions .
 Contraindications:
 Epilepsy
 Impaired liver or kidney functions
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Pregnancy
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Second-line drug for treatment of tape worm infections.
Given in the morning on empty stomach.
Poorly absorbed from gut & excreted in urine.
MOA: adult worm is rapidly killed by inhibition of
oxidative phosphorylation .
Clinical uses: Treatment of most forms of tapeworms.
Purgative is necessary to purge all dead segments&
prevent liberation of ova.
Adverse effects: Mild GI disturbance.
Contraindication:
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Children under 2 y.
Pregnancy.
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MOA: Immobilizes microfilariae and alters their
surface structure ,displacing them from tissues &
making them susceptible to destruction by host
defense mechanism.
Given orally after meals, rapidly absorbed from GIT.
Half- life is 2-3 hrs.
It is excreted in urine as unchanged or metabolite.
Adverse effects: Fever , rash, headache,
GIT problems, cough, pain, retinal hemorrhage,
encephalopathy, lymphadenopathy.
Contraindication: Hypertension, renal disease,
patient with lymphangitis.
MOA: Paralyze nematodes by intensifying GABAmediated transmission of signals in peripheral
nerves.
 Given only orally, rapidly absorbed.
 Does not cross BBB.
 Half- life is 16 hrs.
 Excretion in urine & feces.
 Clinical uses:
 Cutaneous larva migrans.
 Strongyloidiasis.
 Onchocerciasis.
 Filariasis ( it is microfilaricidal ).
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Adverse effects:
 Fatigue , dizziness, GI disturbance.
 Killing of microfilaria result in a Mazotti reaction:
fever, headache, hypotension , tachycardia,
peripheral edema.
 Corneal opacities & other eye lesions.
 Contraindication:
 Concomitant use with other drugs that enhance
GABA (Barbiturates, bnzodiazepines, valproic
acid).
 Pregnancy.
 Meningitis.
 Children under 5 y.
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MOA: Bithionol interferes with the
neuromuscular physiology of helminths, impairs
egg formation and inhibit oxidative
phosphorylation .
 Given orally & Excreted in urine
 Clinical uses: Drug of choice for the treatment of
fascioliasis ( sheep liver fluke).
 Adverse effects: GI disturbance, dizziness,
headache, skin rashes , urticaria, leucopenia.
 Contraindications and precautions:
 Hepatitis , leucopenia.
 Used with caution in children under 8 y.
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Worms (helminths)
Drug of choice
Tapeworms (cestodes)
Niclosamide or Praziquantel or
Albendazole
Roundworms (nematodes)
•Enterobius vermicularis (pinworm)
•Ascaris lumbricoides
•Trichuris trichiura (whipworm)
•Trichinella spiralis (trichinellosis)
•Strongyloides stercoralis
•Necator americanus (hookworm)
•Ancylostoma duodenale
•Onchocerca volvulus (Onchocercosis)
•Wuchereria bancrofti (Elephantiasis)
Mebendazole or Pyrantel
Mebendazole or Pyrantel
Mebendazole or Albendazole
Mebendazole
and Thiabendazole
Thiabendazole
Mebendazole or Pyrantel
Mebendazole, Pyrantel, or
Albendazole
Ivermectin
Diethylcarbamazine
Flukes (trematodes)
•Schistzoma (Schistozomes)
Praziquantel