BNF for Children 2011-2012

296 5.1.11 Metronidazole BNFC 2011–20125 InfectionsMetronidazole is well absorbed orally and the intravenousroute is normally reserved for severe infections.Metronidazole by the rectal route is an effective alternativeto the intravenous route when oral administrationis not possible. Intravenous metronidazole is used forthe treatment of established cases of tetanus; diazepam(section 10.2.2) and tetanus immunoglobulin (section14.5.2) are also used.Topical metronidazole (section 13.10.1.2) reduces theodour produced by anaerobic bacteria in fungatingtumours; it is also used in the management of rosacea(section 13.6).Oral infections Metronidazole is an alternative to apenicillin for the treatment of many oral infectionswhere the patient is allergic to penicillin or the infectionis due to beta-lactamase-producing anaerobes (Table 1,section 5.1). It is the drug of first choice for the treatmentof acute necrotising ulcerative gingivitis (Vincent’sinfection) and pericoronitis; suitable alternatives areamoxicillin (section 5.1.1.3) and erythromycin (section5.1.5). For these purposes treatment with metronidazolefor 3 days is sufficient, but the duration of treatmentmay need to be longer in pericoronitis. Tinidazole islicensed for the treatment of acute ulcerative gingivitis.METRONIDAZOLECautions disulfiram-like reaction with alcohol, clinicaland laboratory monitoring advised if treatmentexceeds 10 days; interactions: Appendix 1 (metronidazole)Hepatic impairment in severe liver disease reducetotal daily dose to one-third, and give once daily; usewith caution in hepatic encephalopathyPregnancy manufacturer advises avoidance of highdoseregimens; use only if potential benefit outweighsriskBreast-feeding significant amount in milk; manufactureradvises avoid large single doses though otherwisecompatible; may give milk a bitter tasteSide-effects gastro-intestinal disturbances (includingnausea and vomiting), taste disturbances, furred tongue,oral mucositis, anorexia; very rarely hepatitis,jaundice, pancreatitis, drowsiness, dizziness, headache,ataxia, psychotic disorders, darkening of urine,thrombocytopenia, pancytopenia, myalgia, arthralgia,visual disturbances, rash, pruritus, and erythemamultiforme; on prolonged or intensive therapy peripheralneuropathy, transient epileptiform seizures,and leucopeniaIndication and doseProtozoal infections section 5.4.2Anaerobic infections (usually treated for 7 daysand for 10–14 days in Clostridium difficileinfection). By mouthChild 1–2 months 7.5 mg/kg every 12 hoursChild 2 months–12 years 7.5 mg/kg (max.400 mg) every 8 hoursChild 12–18 years 400 mg every 8 hours. By rectumChild 1 month–1 year 125 mg 3 times daily for 3days, then twice daily thereafterChild 1–5 years 250 mg 3 times daily for 3 days,then twice daily thereafterChild 5–10 years 500 mg 3 times daily, for 3 days,then twice daily thereafterChild 10–18 years 1 g 3 times daily for 3 days,then twice daily thereafter. By intravenous infusion over 20–30 minutesNeonate 7.5 mg/kg every 12 hoursChild 1–2 months 7.5 mg/kg every 12 hoursChild 2 months–18 years 7.5 mg/kg (max.500 mg) every 8 hoursPelvic inflammatory disease (see also Table 1,section 5.1). By mouthChild 12–18 years 400 mg twice daily for 14 daysAcute ulcerative gingivitis and other acutedental infections. By mouthChild 1–3 years 50 mg every 8 hoursChild 3–7 years 100 mg every 12 hoursChild 7–10 years 100 mg every 8 hoursChild 10–18 years 200–250 mg every 8 hoursHelicobacter pylori eradication section 1.3Surgical prophylaxis. By mouthChild 1 month–12 years 30 mg/kg (max. 500 mg)2 hours before the procedureChild 12–18 years 400–500 mg 2 hours beforethe procedure; up to 3 further doses of 400–500 mgmay be given every 8 hours for high-risk procedures. By intravenous infusionNeonate under 40 weeks postmenstrual age10 mg/kg up to 30 minutes before the procedureNeonate over 40 weeks postmenstrual age 20–30 mg/kg up to 30 minutes before the procedureChild 1 month–12 years 30 mg/kg (max. 500 mg)up to 30 minutes before the procedureChild 12–18 years 500 mg up to 30 minutesbefore the procedure; up to 3 further doses of500 mg may be given every 8 hours for high-riskprocedures. By rectumChild 5–10 years 500 mg 2 hours before surgery;up to 3 further doses of 500 mg may be given every8 hours for high-risk proceduresChild 10–18 years 1 g 2 hours before surgery; upto 3 further doses of 1 g may be given every 8hours for high-risk procedures