Metronidazol Labesfal (Metronidazole)

Metronidazole is employed to manage infections caused by anaerobic bacteria and susceptible protozoa.

• Anaerobic bacterial infections: effective against mixed aerobic‑anaerobic infections, reducing bacterial load.
• Intra‑abdominal infections: helps resolve peritonitis and abscesses originating in the abdomen.
• Pelvic inflammatory disease: targets the anaerobic organisms contributing to PID.
• Bacterial vaginosis: restores normal vaginal flora by eliminating over‑growth of anaerobes.
• Trichomoniasis: eradicates Trichomonas vaginalis in affected patients.
• Clostridioides difficile colitis: reduces toxin‑producing C. difficile bacteria in the colon.

• Metronidazole enters susceptible anaerobic microorganisms and is reduced by intracellular ferredoxin proteins, generating nitro radicals. These reactive intermediates damage DNA and other critical macromolecules, inhibiting nucleic acid synthesis and leading to cell death of the targeted bacteria or protozoa.

Metronidazole may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Nausea: mild to moderate upset stomach.
• Metallic taste: transient alteration of taste perception.
• Headache: occasional mild to moderate headache.
• Diarrhea: loose stools that may be self‑limiting.

Serious or Rare Side Effects

• Seizures: rare neurologic events, especially with high doses.
• Peripheral neuropathy: tingling or numbness in extremities.
• Severe allergic reactions: rash, itching, swelling, or anaphylaxis.
• Stevens‑Johnson syndrome: rare severe skin reaction.
• Liver toxicity: elevated liver enzymes or hepatitis.
• Blood dyscrasias: neutropenia, thrombocytopenia, or anemia.

Metronidazole requires careful consideration of patient‑specific factors before use.

• Pregnancy: Category B – use only if clinical benefit justifies potential risk.
• Renal impairment: dose adjustment may be necessary in severe renal dysfunction.
• Hepatic impairment: monitor liver function tests during therapy.
• Alcohol consumption: avoid alcohol to prevent a disulfiram‑like reaction.
• Drug interactions: review concomitant medications for potential interactions.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze.

Metronidazole can interact with several drugs, requiring vigilance.

Major Interactions (Avoid)

• Alcohol: may cause severe disulfiram‑like reaction.
• Warfarin: potentiates anticoagulant effect, increasing bleeding risk.
• Lithium: may increase lithium serum concentrations and toxicity.
• Live vaccines: reduced efficacy and increased infection risk.

Moderate Interactions (Monitor Closely)

• Phenytoin: may lower metronidazole plasma levels.
• Cimetidine: can increase metronidazole concentrations.
• Carbamazepine: may reduce metronidazole effectiveness.