Source: Medicines & Healthcare Products Regulatory Agency (GB) Revision Year: 2018 Publisher: Creo Pharma Limited, Felsted Business Centre, Felsted, Essex, CM6 3LY
Metronidazole is active against a wide range of pathogenic microorganisms, notably species of Bacteroids, Fusobacteria, Clostridia, Eubacteria, anaerobic cocci and Gardnerella vaginalis.
It is also active against Trichomonas vaginalis, Entamoeba histolytica, Giardia lamblia, Balantidium coli and Helicobacter pylori.
Metronidazole is indicated in adults and children for the following indications:
Consideration should be given to official guidance on the appropriate use of antibacterial agents.
Metronidazole Tablets should be taken during or after meals, swallowed with water and not chewed.
Elderly: Caution is advised in the elderly, particularly at high doses, although there is limited information available on modification of dosage.
Hepatic impairment: Caution is advised in patients with hepatic encephalopathy. One third of the daily dose given once a day should be considered (see section 4.4).
Treatment for 7 days should be satisfactory for most patients but, depending upon clinical and bacteriological assessments, the physician may decide to prolong treatment, e.g. for eradication of infection from sites which cannot be drained or are liable to endogenous recontamination by anaerobic pathogens from the gut, oropharynx or genital tract.
Children >8 weeks to 12 years of age: The usual daily dose is 20-30 mg/kg/day as a single dose or divided into 7.5 mg/kg every 8 hours. The daily dose may be increased to 40 mg/kg, depending on the severity of the infection. Duration of treatment is usually 7 days.
Children <8 weeks of age: 15 mg/kg as a single dose daily or divided into 7.5 mg/kg every 12 hours.
In newborns with a gestation age <40 weeks, accumulation of metronidazole can occur during the first week of life, therefore the concentrations of metronidazole in serum should preferably be monitored after a few days therapy.
Children under 10 years: A more suitable dosage form should be used for this age group.
Prophylaxis against anaerobic infection – chiefly in the context of abdominal (especially colorectal) and gynaecological surgery.
Adults: 1g stat dose 24 hours pre-operatively, followed by 400mg at 8 hourly intervals during the 24 hours preceding operation followed by post-operative iv or rectal administration until the patient is able to take tablets.
Children <12 years: 20-30 mg/kg as a single dose given 1-2 hours before surgery.
Newborns with a gestation age <40 weeks: 10 mg/kg body weight as a single dose before operation.
Children under 10 years: A more suitable dosage form should be used for this age group.
Adults and children over 10 years: 800mg followed by 400mg 8 hourly.
Children under 10 years: A more suitable dosage form should be used for this age group.
Where reinfection is likely, sexual partners should be treated concomitantly.
Adults and adolescents: 2000 mg as a single dose or 200 mg 3 times daily for 7 days or 400 mg twice daily for 5-7 days.
Children <10 years: 40 mg/kg orally as a single dose or 15–30 mg/kg/day divided in 2-3 doses for 7 days; not to exceed 2000 mg/dose.
Children under 10 years: A more suitable dosage form should be used for this age group.
Adults: 400mg twice daily for 7 days, or 2g as a single dose for one day only.
Adolescents: 400 mg twice daily for 5-7 days or 2000 mg as a single dose.
Adults >10 years: 400 to 800 mg 3 times daily for 5-10 days.
Children 7 to 10 years: 200 to 400 mg 3 times daily for 5-10 days.
Children 3 to 7 years: 100 to 200 mg 4 times daily for 5-10 days.
Children 1 to 3 years: 100 to 200 mg 3 times daily for 5-10 days.
Alternatively, doses may be expressed by body weight: 35 to 50 mg/kg daily in 3 divided doses for 5 to 10 days, not to exceed 2400 mg/day.
Children under 7 years: A more suitable dosage form should be used for this age group.
Adults >10 years: 2000 mg once daily for 3 days, or 400 mg. three times daily for 5 days, or 500 mg twice daily for 7 to 10 days.
Children 7 to 10 years: 1000 mg once daily for 3 days.
Children 3 to 7 years: 600 to 800 mg once daily for 3 days.
Children 1 to 3 years: 500 mg once daily for 3 days. Alternatively, as expressed in mg per kg of body weight: 15-40 mg/kg/day divided in 2-3 doses.
Children under 7 years: A more suitable dosage form should be used for this age group.
Adults and children over 10 years: 200mg three times daily.
Children under 10 years: A more suitable dosage form should be used for this age.
Adults and children over 10 years: 200mg three times daily.
Adults and children over 10 years: 400mg three times daily.
As a part of a combination therapy, 20 mg/kg/day not to exceed 500 mg twice daily for 7-14 days. Official guidelines should be consulted before initiating therapy.
For oral administration.
Nausea, vomiting, diarrhoea, anorexia, metallic taste, headache, dizziness and occasionally insomnia and drowsiness. Transiently increased liver enzyme activities have been reported rarely.
Transient epileptiform seizures have been reported following intensive or prolonged therapy. Other adverse effects occurring in these circumstances include peripheral motor neuropathy, blood dyscrasias and liver damage.
The combination of alcohol and metronidazole has been said to cause disulfiram type reactions in about 10% of individuals with sudden onset of excitement, giddiness, flushing, nausea, headache, hypotension and dyspnoea. However the mechanism of this reaction has been questioned.
Unlikely to be required.
Disulfiram type reactions should be treated with intravenous fluids and plasma expanders if necessary. Symptomatic and supportive.
36 months.
Keep blister in the outer carton, protected from light.
Blister pack (aluminium (25 µm)/PVC (250 µm)), pack sizes of 21 tablets. Not all pack sizes may be marketed.
Not applicable.
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