Metronidazol-Human Teva Gyógyszergyár (Metronidazole)

Metronidazole acts on anaerobic bacteria and certain protozoa, making it useful for a range of infections.

• Anaerobic bacterial infections: effective against infections caused by anaerobic organisms, reducing bacterial load.
• Clostridioides difficile‑associated colitis: helps resolve toxin‑mediated diarrhea and colitis.
• Bacterial vaginosis: restores normal vaginal flora by eliminating pathogenic anaerobes.
• Trichomoniasis: eradicates Trichomonas vaginalis, relieving symptoms.
• Amoebic liver abscess: targets Entamoeba histolytica in hepatic tissue.
• Pelvic inflammatory disease: assists in controlling mixed anaerobic pelvic infections.

• Metronidazole is reduced by electron‑transport proteins of anaerobic microorganisms, generating reactive nitro radicals that damage DNA and inhibit nucleic acid synthesis. This leads to strand breakage and cell death, selectively affecting anaerobic bacteria and susceptible protozoa while sparing aerobic cells.

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

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Metallic taste: transient alteration of taste perception.
• Diarrhea: loose stools, usually self‑limiting.
• Abdominal pain: cramping or discomfort in the abdomen.
• Headache: mild to moderate headache episodes.
• Dizziness: occasional light‑headedness.

Serious or Rare Side Effects

• Severe allergic reactions: rash, itching, swelling, or anaphylaxis.
• Seizures: rare neurologic events, especially with high doses.
• Neutropenia: reduced white blood cell count, increasing infection risk.
• Stevens‑Johnson syndrome: severe skin and mucous membrane disorder.
• Hepatic dysfunction: elevated liver enzymes or jaundice.
• Peripheral neuropathy: tingling or numbness in extremities.

Metronidazole requires careful use in specific clinical situations.

• Renal impairment: adjust dosing and monitor renal function.
• Hepatic disease: monitor liver enzymes and consider dose modification.
• Alcohol consumption: avoid alcohol to prevent disulfiram‑like reactions.
• Pregnancy: use only when benefits outweigh potential risks.
• Concurrent warfarin therapy: monitor INR closely for increased anticoagulation.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze.

Metronidazole can interact with several medicines, requiring vigilance.

Major Interactions (Avoid)

• Alcohol: may cause severe disulfiram‑like reaction.
• Warfarin: increased anticoagulant effect, risk of bleeding.
• Lithium: elevated lithium levels, potential toxicity.

Moderate Interactions (Monitor Closely)

• Phenytoin: may reduce metronidazole plasma concentrations.
• Cimetidine: can increase metronidazole levels, enhancing effects.
• Theophylline: possible increased theophylline toxicity.