FLAGYL

Posology 1.

Prophylaxis against anaerobic infection:

Chiefly in the context of abdominal (especially colorectal) and gynaecological surgery. Adults: 400 mg 8 hourly during 24 hours immediately preceding operation followed by postoperative intravenous or rectal administration until the patient is able to take tablets.

Paediatric population 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. 2.

Anaerobic infections:

The duration of a course of Flagyl treatment is about 7 days but it will depend upon the seriousness of the patient’s condition as assessed clinically and bacteriologically.

Treatment of established anaerobic infection:

Adults: 800 mg followed by 400 mg 8 hourly. 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. 5 mg/kg every 12 hours. 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 preferable be monitored after a few days therapy.

3.

Protozoal and other infections:

Dosage is given in terms of metronidazole or metronidazole equivalent Children Duration of dosage in days Adults and children over 10 years 7 – 10 years 3 – 7 years 1 – 3 years Urogenital trichomoniasis (Where re-infection is likely, in adults the consort should receive a similar course of treatment concurrently) 7 Or 5 – 7 2000 mg as a single dose Or 200 mg three times daily or 400 mg twice daily 40 mg/kg orally as a single dose Or 15 – 30 mg/kg/day divided in 2 – 3 doses; not to exceed 2000 mg/kg dose Bacterial vaginosis 5 – 7 Or 1 400 mg twice daily Or 2000 mg as a single dose N/A Amoebiasis (a) Invasive intestinal disease in 5 800 mg three times daily 400 mg three 200 mg four times 200 mg three times 4.

Eradication of Helicobacter pylori in paediatric patients: susceptible subjects times daily daily daily (b) Intestinal disease in less susceptible subjects and chronic amoebic hepatitis 5 – 10 (c) Amoebic liver abscess also other forms of extra- intestinal amoebiasis 5 400 mg three times daily 200 mg three times daily 100 mg four times daily 100 mg three times daily 5 – 10 400 – 800 mg three times daily 200 – 400 mg three times daily 100 – 200 mg four times daily 100 – 200 mg three times daily(d) Symptomless cyst passers 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 Giardiasis 3 Or 5 Or 7 – 10 2000mg once daily Or 400 mg three times daily Or 500 mg twice daily 1000 mg once daily 600 – 800 mg once daily 500 mg once daily Alternatively, as expressed in mg per kg of body weight: 15 – 40 mg/kg/day divided in 2 – 3 doses.

The frequency of adverse events listed below is defined using the following convention: very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1,000 to < 1/100); rare (≥ 1/10,000 to < 1/1,000); very rare (< 1/10,000), not known (cannot be estimated from the available data).

Serious adverse reactions occur rarely with standard recommended regimens. Clinicians who contemplate continuous therapy for the relief of chronic conditions, for periods longer than those recommended, are advised to consider the possible therapeutic benefit against the risk of peripheral neuropathy.

Blood and lymphatic system disorders:

Very rare: agranulocytosis, neutropenia, thrombocytopenia, pancytopenia Not known: leucopenia.

Immune system disorders:

Rare: anaphylaxis Not known: angiodema, urticaria, fever.

Metabolism and nutrition disorders:

Not known: anorexia.

Psychiatric disorders:

Very rare: psychotic disorders, including confusion and hallucinations. g. g. ataxia, dysarthria, gait impairment, nystagmus and tremor) which may resolve on discontinuation of the drug • drowsiness, dizziness, convulsions, headaches Not known: • during intensive and/or prolonged metronidazole therapy, peripheral sensory neuropathy or transient epileptiform seizures have been reported.

In most cases neuropathy disappeared after treatment was stopped or when dosage was reduced • aseptic meningitis Eye disorders: Very rare: vision disorders such as diplopia and myopia, which, in most cases, is transient.

Not known: optic neuropathy/neuritis Ear and labyrinth disorders:

Metronidazole has no direct activity against aerobic or facultative anaerobic bacteria. Regular clinical and laboratory monitoring (especially leucocyte count) are advised if administration of Flagyl for more than 10 days is considered to be necessary and patients should be monitored for adverse reactions, such as peripheral or central neuropathy (such as paraesthesia, ataxia, dizziness, convulsive seizures).

Metronidazole should be used with caution in patients with active or chronic severe peripheral and central nervous system disease due to the risk of neurological aggravation. Cases of severe hepatotoxicity/acute hepatic failure, including cases with a fatal outcome with very rapid onset after treatment initiation in patients with Cockayne syndrome have been reported with products containing metronidazole for systemic use.

In this population, metronidazole should therefore be used after careful benefit- risk assessment and only if no alternative treatment is available. Liver function tests must be performed just prior to the start of therapy, throughout and after end of treatment until liver function is within normal ranges, or until the baseline values are reached.

If the liver function tests become markedly elevated during treatment, the drug should be discontinued. Patients with Cockayne syndrome should be advised to immediately report any symptoms of potential liver injury to their physician and stop taking metronidazole.

Cases of severe bullous skin reactions such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) or acute generalised exanthematous pustulosis (AGEP) have been reported with metronidazole. If symptoms or signs of SJS, TEN or AGEP are present, Flagyl treatment must be immediately discontinued.

There is a possibility that after Trichomonas vaginalis has been eliminated a gonococcal infection might persist. The elimination half-life of metronidazole remains unchanged in the presence of renal failure. The dosage of metronidazole therefore needs no reduction.

1.