Metra 400 mg Tablet

Metronidazole 400 mg


Metra Tablet-400: Each film coated tablet contains Metronidazole BP 400mg.

Metra Suspension: Each 5ml contains Benzoyl Metronidazole equivalent to Metronidazole BP 200mg.


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.

  • 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).
  • Acute ulcerative gingivitis.
  • Anaerobically infected leg ulcers and pressure sores.
  • Acute dental infections due to anaerobic organisms.
  • Antibiotic associated pseudomembranus colitis.

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)-

  • 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  gingivitis (Adults & Children over 10 yrs)-

  • 200 mg tid for 3 days

Acute ulcerative  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 hours before  surgery for 1 days

Surgical prophylaxis (Children)-

  • Children 1-10 yrs: 7.5 mg/kg tid

Metra is contraindicated in patients with a history of hypersensitivity  to metronidazole or other nitromidazole derivatives.


Patients with hepatic disorders, Candidiasis and CNS disease should take Metra  Cautiously under the supervision of Physician.


Alcoholic beverages should not be consumed during and at least one day after using Metra.


Hepatic impairment: Metronidazole is mainly metabolised by hepatic oxidation. Substantial impairment of metronidazole clearance may occur in the presence of advanced hepatic insufficiency. Significant cumulation may occur in patients with hepatic encephalopathy and the resulting high plasma concentrations of metronidazole may contribute to the symptoms of the encephalopathy. Metronidazole should therefore, be administered with caution to patients with hepatic encephalopathy. The daily dosage should be reduced to one third and may be administered once daily. Patients should be warned that metronidazole may darken urine.

Renal impairment: The elimination half-life of metronidazole remains unchanged in the presence of renal failure. The dosage of metronidazole therefore needs no reduction. Such patients however retain the metabolites of metronidazole. The clinical significance of this is not known at present. In patients undergoing haemodialysis metronidazole and metabolites are efficiently removed during an eight hour period of dialysis. Metronidazole should therefore be re-administered immediately after haemodialysis. No routine adjustment in the dosage of Metronidazole need be made in patients with renal failure undergoing intermittent peritoneal dialysis (IDP) or continuous ambulatory peritoneal dialysis (CAPD).


Metallic taste, nausea, vomiting, diarrhoea, drowsiness, rashes may be observed during treatment.


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.

  • Disulfiram: Psychotic reactions have been reported in patients who were using metronidazole and disulfiram concurrently.
  • Alcohol: Alcoholic beverages and drugs containing alcohol should not be consumed during therapy and for at least one day afterwards because of the possibility of a disulfiram-like (antabuse effect) reaction (flushing, vomiting, tachycardia). Oral anticoagulant therapy (warfarin type): Potentiation of the anticoagulant effect and increased hemorrhagic risk caused by decreased hepatic catabolism. In case of co-administration, prothrombin time should be more frequently monitored and anticoagulant therapy adjusted during treatment with metronidazole.
  • Lithium: Plasma levels of lithium may be increased by metronidazole.
  • Cyclosporin: Serum cyclosporin and serum creatinine should be closely monitored when co-administration is necessary.
  • Phenytoin or phenobarbital: increased elimination of metronidazole resulting in reduced plasma levels.
  • 5-Fluorouracil: Reduced clearance of 5-fluorouracil resulting in increased toxicity of 5-fluorouracil.
  • Busulfan: Plasma levels of busulfan may be increased by metronidazole, which may lead to severe busulfan toxicity.

Single oral doses of metronidazole, up to 12 g have been reported in suicide attempts and accidental overdoses. Symptoms were limited to vomiting, ataxia and slight disorientation. There is no specific antidote for metronidazole overdosages. In case of suspected massive overdosages, a symptomatic and supportive treatment should be instituted.


Store below 30°C. Keep protected from light. Keep medicines out of the reach of children. Do not use later than the date of expiry.


Metra tablet: Box containing 10×10 Tablets in blister pack.

Metra Suspension: Bottle containing 60 ml Suspension.

Metra 400 mg Tablet
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