Antibiotic guidelines
Department of Internal Medicine
PMHC
The guidelines suggested below are aimed to encourage rational, safe, effective and economic use of the
limited number of anti-infective drugs we have available to us. Where possible these guidelines follow the
South African essential drug list guidelines. The choice of antibiotic in each guideline is based on the best
available evidence from international and existing South African guidelines.
The guidelines suggest empirical treatment of common conditions and syndromes. It must be stressed that
taking appropriate samples for culture is of paramount importance both for the individual patient
and for monitoring of resistance. If a patient has a positive culture result their treatment should be
rationalised to the narrowest spectrum of antibiotic possible to prevent resistance occurring. If you are in
doubt about what antibiotic to use please call one of the medical consultants for advice.
The department of internal medicine is currently in the process of auditing microbial isolates from the
medical wards. The sensitivity patterns will be analysed and this may lead to changes in the antibiotic
guidelines. Currently the most common infecting organism is given for each infection.
These guidelines are not compulsory but if you wish to deviate from the guidelines you must be prepared to
justify your decision. These guidelines only apply to adult patients under the care of the department of
medicine.
The guidelines outline antibiotic choices only, other aspects of management will be covered in the
department of internal medicine management protocols.
1.
Upper respiratory tract infections
a. Tonsillitis / pharnygitis – (Streptococcus pyogenes)
i. First line – Pencillin V 500mg 6hrly p.o. for 10 days
ii. If unable to swallow – benzyl penicillin 1.2 g 6 hrly i.v. – until able to swallow
then switch to penicillin V
iii. Penicillin allergry – erythromycin 500mg 6 hrly p.o. for 5 days (can be given i.v.
in necessary)
b. Otitis externa – clean and dry ear with acetic acid – use flucloxacillin 500mg 6 hrly p.o.
for 5 days if evidence of bacterial infection ( for severe infection in diabetic patients use
ciprofloxacin 500mg 12hrly p.o. and gentamicin 5mg/kg daily i.v.i.)
c. Otitis media- (S.pneumoniae)
i. Acute – amoxicillin 500mg 8 hrly p.o. for 5 days
1. Pencillin allergy – erythromycin 500mg 6 hrly p.o. for 5 days
ii. Chronic – dry mopping and refer to ENT
d. Oropharnygeal candadiasis – (Candida albicans)
i. First line – nystatin 100,000 iu 6 hourly p.o. for 7 days
ii. Alternative – fluconazole 750mg stat po.
2.
Lower respiratory tract infections
a. LRTI / Pneumonia – (S.pneumoniae, Heamophilus influenzae)
i. Mild – amoxicillin 500mg 8 hourly p.o. for 5 days
1. Penicillin allergy – use erythromycin 500mg 6 hourly orally.
ii. Severe – Benzyl Penicillin 1.2g 6 hrly i.v.i. until patient improves and can be
changed to oral therapy
iii. In severe pneumonia add gentamicin 5mg/Kg daily..
iv. If atypical pneumonia is suspected add erythromycin 500mg 6 hrly p.o. or 1g
6hrly ivi.
b. Infective exacerbation of chronic obstructive airways disease – (S.pneumoniae,
H.influenzae, Moraxella cattarhalis)
i. Amoxicillin 500mg 8 hrly p.o. for 5 days
1. Penicillin allergic patients use either erythromycin 500mg 6 hrly p.o. or
doxicyclin 100mg daily p.o.
c. Tuberculosis – (Mycobacterium tuberculosis)
d.
i. See EDL – RHZE – remember to choose dose according to weight and also to
prescribe pyridoxine
Pneumocystis pneumonia – Cotrimoxazole 4 tabs 8 hrly p.o or 4 vials 8 hrly ivi. for 21
days then 2 tabs daily for life. Note if oxygen saturation is <93% or PaO2 <8 kPa add
prednisolone 0.5mg/kg 12 hrly p.o. for 7 days then reduce dose over next 2 weeks.
3.
Gastrointestinal tract infections
a. Oesophageal candadiasis – (C. albicans)
i. Fluconazole 200mg daily p.o. for 2 weeks
b. Helicobacter pylori infection – Omeprazole 20mg daily po, amoxicillin 1g 12 hrly p.o.
and metronidazole 400mg 8 hourly p.o. for 7 days
c. Gastroenteritis – (many enteric viruses, Campylobacter jejuni, Esherichia coli,
Salmonella species ) mainstay of treatment is fluid replacement – patients who are
systemically unwell with fever use ciprofloxacin 500mg 12hrly p.o. for 5 days
d. Cholera – (Vibrio cholera) fluid replacement essential – use ciprofloxacin 500mg stat p.o.
to reduce duration of illness and carriage
e. Dysentery
i. Bacterial dysentery – (Shigella species) ciprofloxacin 500mg 12 hrly p.o. 5 days
ii. Amoebic dysentery – (Amoeba histolitica) metronidazole 400mg 8 hrly p.o.
5days
f. Typhoid – Ciprofloxacin 500mg 12 hrly po 10 days, use ceftriaxone 2g daily in severely
ill patients
g. Liver abscess
i. Amoebic – metronidazole 800mg 8 hrly p.o. 7-10 days
ii. Polymicrobial – co-amoxiclav 1.2g 8 hrly i.v.i and metronidazole 500mg 8 hrly
i.v.i. .until improvement seen (will need aspiration)
4.
Cardiac infections
a. Rheumatic fever – (S.pyogenes)
i. Acute attack – benzyl penicillin 1.2 g 6 hourly i.v.i. can change to oral penicillin
v or amoxicillin as soon as patient is well enough – treat for 5 days
ii. Prophylaxis – benzathine penicillin 1.2g monthly i.m.i. or pen VK 250mg 12
hourly
b. Infective endocarditis – (various organisms including S.viridans, Staphlococcus areus,
HACEK etc) initial treatment – benzyl penicillin 1.2g 6 hrly i.v.i. and gentamicin 40mg
12 hrly i.v.i.. Adjust treatment according to blood culture results. (Penicillin allergy use
vancomycin 500mg 12 hrly i.v.i.)
c. Pericarditis – usually tuberculosis – treat with standard antituberculosis treatment and add
prednisolone 60mg daily for one month then taper – see guideline
5.
Central nervous system infections
a. Viral meningitis – no specific antiviral therapy indicated
b. Bacterial meningitis – (Nessiria meningitides, S.pneumoniae, H.influenzae, Listeria
monocytogenes)
i. First line – ceftriaxone 2g 12 hrly i.v.i. – give as soon as the diagnosis of
meningitis is expected. Change therapy as soon as a specific diagnosis (e.g.
benzyl penicillin for pneumococcal meningitis) is made or if meningitis is ruled
out after lumber puncture.
c. Tuberculous meningitis – (M.tuberculosis) see TB treatment guidelines and guideline for
use of dexamethasone in TB meningitis
d. Cryptococcal meningitis – (Cryptococcus neoformans) first line amphoteracin 1.0 mg/kg
daily i.v.i. for 2 weeks followed by fluconazole 400mg daily p.o. for 8 weeks then
fluconazole 200mg daily for life
e. Cerebral toxoplasmosis – (Toxoplasma gondi) cotrimoxazole 4 tabs 12 hourly p.o. for 30
days then 2 tabs daily for life. (or until CD4 count >200 for 6 months)
f.
Viral encephalitis –(H.simplex) if HSV encephalitis suspected use acyclovir 10mg/kg 8
hrly i.v.i. for 21 days (can change to oral acyclovir once the patient responds)
6.
Urinary and genital tract infections
a. Urinary tract infection –(E.coli, Proteus mirabilis, Klebsiella sp, Pseudomonas
auerigenosa)
b. ciprofloxacin 250mg 12 hrly p.o. for 5 days
i. Can give ciprofloxacin 500mg single p.o. dose to non pregnant women
ii. Pregnant women – nitrofurantoin 100mg 6 hrly p.o. for 5 days
c. Pyelonephritis – (E.coli, P. mirabiliss, K. areogenes, P. auerigenosa)
i. First line – ciprofloxacin 500mg 12 hrly p.o.for 5 days
ii. Second line (or in severely ill patients with signs of SIRS or vomiting) –
cefuroxime 1.5g 8 hrly i.v.i. for 5 days or until able to take oral medication then
change to ciprofloxacin 500mg 12 hrly p.o.
d. STI’s – refer to DOH protocols
i. Male discharge – (N. gonorrhoeae, C.trachomatis) cefixime 400mg po. stat,
doxicycline 100mg 12 hrly p.o. for 7 days
ii. Female discharge –(N. gonorrhoeae, C.trachomatis, G.vaginalis, Trichomonas)
ceftriaxone 250mg i.m.i. stat, doxicycline 100mg 12 hrly p.o. for 7 days and
metronidazole 2g stat p.o.
iii. Pelvic inflammatory disease –mild treat as for female discharge severe – admit
and give- cefuroxime 750mg 8 hrly i.v., gentamicin 5mg i.v. daily for 5 days
and doxicycline 100mg 12 hrly p.o. for 7 days.
iv. Genital ulcers – (Treponema pallidum, Cl.trachomatis, H.ducreyi,
C.granulomatis) benzathine penicillin 2.4 mu i.m.i. stat, erythromycin 500mg 6
hrly p.o. for 7 days. ( also consider acyclovir 400mg 8hrly p.o. for 5 days if has
herpes simplex)
7.
Skin infections
a. Impetigo – (S.aureus)
i. flucloxacillin 250mg 6 hrly p.o. 5 days
ii. Penicillin allergy – erythromycin 250mg 6hrly p.o. 5 days
b. Erysipelas – (S.pyogenes / S.aureus)
i. Flucloxacillin 500mg 8 hrly p.o. 5 days
ii. Penicillin allergy – erythromycin 250mg 6 hrly p.o. for 5 days
c. Cellulitis – (S.pyogenes, S.aureus)
i. Mild – flucloxacillin 500mg 6 hourly p.o. for 5 days
1. Penicillin allergy – use erythromycin 500mg 6 hrly p.o. for 5 days
ii. Severe – benzyl pencillin 1.2g 6 hrly i.v. and flucloxacillin 1g 6hrly i.v. until
improved (swap to oral flucloxacillin as soon as improving)
iii. Faliure to improve – consider another diagnosis – use cefuroxime 1.5 8 hrly i.v.
and gentamicin 5mg/kg daily i.v.
iv. MRSA – be guided by sensitivities – use two antibiotics to which organism is
sensitive – ask advice of medical consultant
d. Deep seated skin infection (various Streptococci and other gram negative and positive
organisms) – benzyl penicillin 1.2g 6 hrly,i.v.i. flucloxacillin 1g 6 hrly i.v.i. and
gentamicin 5mg/kg daily i.v. (can also add clindamycin)
e. Herpes simplex – (Herpes simpex virus 1 and 2)
i. Acute attack – try to start during prodrome – acyclovir 200mg 5 times a day p.o.
for 7 days
f. Herpes zoster – (Varicella zoster)
i. Zoster - if diagnosed early with fresh blisters use – acyclovir 800mg 6 hrly p.o.
for 7 days
ii. Chickenpox in adults – use acyclovir 800mg 6 hrly p.o. for 7 days. If patient
severly ill especially with lung involvement use –aciclovir 10mg/kg 8 hrly i.v.i.
until improvement occurs
g.
8.
9.
Scabies – (Sarcoptes scabiii)
i. Use benzyl benzoate one application – remember to treat all family members
Sepsis
a.
General principles of management
i. Try and determine the source of sepsis and use antibiotics appropriate to the
source of infection. Remember malaria can prevent with sepis.
ii. Sepsis source unknown – use ceftriaxone 2g daily i.v. add gentamicin 5 mg/kg
daily i.v. and metronidazole 500mg 8hrly i.v. for intra-abdominal infections.
Check renal function and adjust gentamicin dose as appropriate.
Malaria – (Plasmodium falciparum and other Plasmodium sp.)
i. Co-artem is the treatment of choice for non severe uncomplicated malaria.
The dose regimen is based on weight as shown below. The patient should take a
stat dose then take the next dose after 8 hours then take a dose 12 hourly for the
next two days (i.e. a total of 6 doses are taken).
Weight of patient
Dose (6 doses in total as shown above)
10 – 15 Kg
1tab
15 – 25 Kg
2 tabs
25 – 35 Kg
3 tabs
35 – 65 Kg
4 tabs
>65 Kg
4 tabs as above given with a fatty meal of
milk to ensure absorption
ii. Complicated malaria – Quinine 600mg 8 hrly for 7 days
1. If intravenous quinine used give 20mg/kg over 4 hours then after 8
hours give quinine 10mg/kg over 4 hours every 8 hours until the patient
can take oral quinine. Monitor closely for hypoglycaemia
2. In complicated malaria also give oral doxicycline 100mg 12 hourly for
7 days. In children, pregnant women, and patients who are unconscious
use clindamycin iv 10mg/kg 12 hourly until able to take oral
doxicycline.
10. Surgical and orthopaedic infections
a. Please refer to protocols from the relevant departments
11. HIV infection
a. Please refer to Department of health antiretroviral treatment guidelines
b. Patients admitted to hospital who are taking antiretrovirals should generally have their
treatment continued unless interruption is specifically indicated. If unsure ask advice
from senior medical staff. Please make sure you write up their treatment correctly. There
are many potential interactions between antiretrovirals and other medication. Before
starting new medication in patients on antiretrovirals consider possible drug interactions
and if unsure ask advice.
12. Reserve antibiotics
a. The following antibiotics should be kept in pharmacy for use in specific indications under
consultant physician only direction
Piperacillin, piptazobactam, co-amoxiclav, vancomycin, amikacin meropenem, valaciclovir,
ganciclovir and valganciclovir
Date of guideline December 2008
Date of review December 2009
Signed