Indication
Metronidazole is indicated in the treatment of following diseases:
The prevention of post-operative infections due to anaerobic bacteria (particularly species of bacteroides and anaerobic streptococci).
The treatment of septicaemia, bacteraemia, peritonitis, brain abscess, pelvic abscess, pelvic cellulitis and post-operative wound infections caused by anaerobes.
In the treatment of urogenital trichomoniasis.
Bacterial vaginosis (also known as non-specific vaginitis).
All forms of amoebiasis (intestinal, extra-intestinal disease and that of symptomless cyst passers).
Giardiasis.
Acute ulcerative gingivitis.
Anaerobically infected leg ulcers and pressure sores.
Acute dental infections due to anaerobic organisms.
Antibiotic associated pseudomembranus colitis.
Pharmacology
Metronidazole is a member of the imidazole class of antibacterial drug and is classified therapeutically as an antiprotozoal agent. The 5-nitro group of Metronidazole is reduced by anaerobes metabolically. Studies have demonstrated that the reduced form of this drug interacts with DNA and gives bactericidal action of Metronidazole.
Dosage
Tablet and Suspension:
Trichomoniasis (Adults & Children over 10 yrs)-
200 mg tid or 400 mg bid for 7 days
800 mg in the morning and 1-2 gm at night for 2 days
2 gm as a single dose for 1 days
Trichomoniasis (Children)-
Children 7-10 yrs: 100 mg tid
Children 3-7 yrs: 100 mg bid
Children 1-3 yrs: 50 mg tid
Intestinal amoebiasis (Adults & Children over 10 yrs)-?ÿ
800 mg tid for 5 days
Intestinal amoebiasis (Children)-
Children 7-10 yrs: 400 mg tid
Children 3-7 yrs: 200 mg qid
Children 1-3 yrs: 200 mg tid
Extra-intestinal & Asymptomatic amoebiasis (Adults & Children over 10 yrs)-
400-800 mg tid for 5-10 days
Extra-intestinal & Asymptomatic amoebiasis (Children)-
Children 7-10 yrs: 200-400 mg tid
Children 3-7 yrs: 100-200 mg qid
Children 1-3 yrs: 100-200 mg tid
Giardiasis (Adults & Children over 10 yrs)-
2 gm once daily for 3 days
Giardiasis (Children)-
Children 7-10 yrs: 1 gm once daily
Children 3-7 yrs: 600-800 mg once daily
Children 1-3 yrs: 500 mg once daily
Acute ulcerative?ÿ gingivitis (Adults & Children over 10 yrs)-
200 mg tid for 3 days
Acute ulcerative?ÿ gingivitis (Children)-
Children 7-10 yrs: 100 mg tid
Children 3-7 yrs: 100 mg bid
Children 1-3 yrs: 50 mg tid
Acute dental infections (Adults & Children over 10 yrs)-
200 mg tid for 3-7 days
Bacterial Vaginosis (Adults & Children over 10 yrs)-
400 mg bid for 7 days
2 gm as a single dose for 1 days
Leg ulcers and pressure sores (Adults & Children over 10 yrs)-
400 mg tid for 7 days
Anaerobic infections (Adults & Children over 10 yrs)-
800 mg initially and then 400 mg tid for 7 days
Anaerobic infections (Children)-
Children 1-10 yrs: 7.5 mg/kg tid
Surgical prophylaxis (Adults & Children over 10 yrs)-
400 mg tid started 24?ÿ hours before?ÿ surgery for 1 days
Surgical prophylaxis (Children)-
Children 1-10 yrs: 7.5 mg/kg tid
Vaginal Gel:
The recommended dose is one applicator full of Metronidazole gel (approximately 5 grams containing approximately 37.5 mg of Metronidazole) intravaginally once or twice a day for 5 days. For once a day dosing, Metronidazole gel should be administered at bedtime.
Suppository:
Anaerobic Infections-
Adults: 1 g every 8 hours for 3 days, then 1 g every 12 hours.
Children: 5-10 years: 500 mg every 8 hours for 3 days, then every 12 hours, Over 10 years adult dose.
Surgical Prophylaxis-
Adults: 1 g 2 hours before surgery; up to 3 further doses of 1 g may be given every 8 hours for high risk procedures.
Children: 5-10 years: 500 mg 2 hours before surgery; up to 3 further doses of 500 mg may be given every 8 hours for high risk procedures.
IV Infusion:
Metronidazole intravenous infusion requires no dilution and should not be mixed with any other drugs prior to administration.
Adults and children over 12 years: Infuse 500 mg 8 hourly at a rate of 5 ml/minute and a maximum of 4 g should not be exceeded during a 24-hour period. Treatment for 7 days is sufficient for most patients, but treatment can be extended, especially for cases where reinfection is likely. For surgical prophylaxis, administration shortly before surgery should be followed by 8-hourly doses for the next 24 hours.
Children under 12 years: 7.5 mg/kg body weight/day every 8 hours at a rate of 5 ml/minute.
Interaction
Metronidazole has been found to interact with alcohol, warfarin, phenytoin, phenobarbitone, fluorouracil, disulfiram, lithium and cimetidine.
Contradiction
Metronidazole is contraindicated in patients with a history of hypersensitivity to Metronidazole or other Nitroimidazole derivatives.
Side Effect
Metallic taste, nausea, vomiting, diarrhoea, drowsiness, rashes may be observed during treatment.
Pregnancy
US FDA Pregnancy Category of Metronidazole is B. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Metronidazole have been shown to be excreted in human milk. So, caution should be exercised when Metronidazole is administered to a nursing woman.
Precaution
Metronidazole should be given with caution in anaemia or other blood disorders, liver disease, disease of the nervous system, seizures etc.
Overdose
Storage
Keep in a dry place away from light and heat. Keep out of the reach of children.