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Therapeutic action
- Antiprotozoal, antibacterial (group of nitroimidazoles)
Indications
- Amoebiasis, giardiasis, trichomoniasis
- Bacterial vaginitis, infections due to anaerobic bacteria (e.g. Clostridium sp, Bacteroides sp, etc.)
Forms and strengths
- 250 mg and 500 mg tablets
- 200 mg/5 ml oral suspension
Dosage and duration
Amoebiasis
- Child: 15 mg/kg 3 times daily
- Adult: 500 mg 3 times daily
The treatment lasts 5 days in intestinal amoebiasis and 5 to 10 days in hepatic amoebiasis.
Giardiasis
- Child: 30 mg/kg once daily for 3 days
- Adult: 2 g once daily for 3 days
Trichomoniasis and bacterial vaginitis
- Adult: 2 g single dose
In the event of trichomoniasis, also treat sexual partner.
Infections due to anaerobic bacteria
- Child: 10 mg/kg 3 times daily
- Adult: 500 mg 3 times daily
According to indication, metronidazole may be used in combination with other anti bacterials; treatment duration depends on indication.
Contra-indications, adverse effects, precautions
- Do not administer to patients with hypersensitivity to metronidazole or another nitroimidazole (tinidazole, secnidazole, etc.).
- May cause: gastrointestinal disturbances; rarely: allergic reactions, brownish urine, headache, dizziness. Risk of antabuse reaction when combined with alcohol.
- Administer with caution in patients taking oral anticoagulants (risk of haemorrhage), lithium, phenytoin, ergometrine (increased plasma concentrations of these drugs).
- Reduce total daily dose to one third and give once daily to patients with severe hepatic impairment.
- Pregnancy: no contra-indication; divide into smaller doses, avoid prolonged use.
- Breast-feeding: significantly excreted in milk (risk of gastrointestinal disturbances in breastfed infants); divide into smaller doses, avoid prolonged use.
Storage
For the oral suspension: follow manufacturer’s instructions.