Metronidazol Actavis (Metronidazole)

Metronidazole is a nitroimidazole antibiotic that targets anaerobic bacteria and protozoal organisms.

• Bacterial vaginosis: eliminates the overgrowth of anaerobic bacteria, restoring normal vaginal flora.
• Trichomoniasis: eradicates Trichomonas vaginalis, relieving genital symptoms.
• Amoebiasis: clears intestinal Entamoeba histolytica infection, preventing dysentery.
• Giardiasis: treats Giardia lamblia infection, reducing diarrhea and malabsorption.
• Anaerobic bacterial infections: combats susceptible anaerobic bacteria in various body sites, aiding infection control.
• Clostridioides difficile infection: reduces toxin‑producing C. difficile, helping resolve colitis.

• Metronidazole enters susceptible anaerobic cells by passive diffusion. Inside the microorganism, its nitro group is reduced by ferredoxin‑type proteins, generating reactive nitro radicals. These cytotoxic radicals interact with DNA, causing strand breakage and inhibiting nucleic acid synthesis, which leads to cell death. The selective activation in low‑oxygen environments accounts for its activity against anaerobic bacteria and certain protozoa, and contributes to its therapeutic efficacy.

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

Common Side Effects

• Nausea: mild stomach upset often occurring early in therapy.
• Metallic taste: a transient metallic sensation in the mouth.
• Diarrhea: loose stools that may be self‑limiting.
• Headache: mild to moderate headache without focal signs.

Serious or Rare Side Effects

• Seizures: rare central nervous system excitation leading to convulsions.
• Peripheral neuropathy: numbness or tingling in extremities that may be irreversible.
• Severe allergic reactions: including Stevens‑Johnson syndrome, toxic epidermal necrolysis, or anaphylaxis.

Before prescribing Metronidazol Actavis, clinicians should consider several safety precautions.

• Assess renal function: dose adjustment may be required in patients with impaired kidney function.
• Avoid alcohol: concurrent intake can cause a disulfiram‑like reaction with flushing and tachycardia.
• Use caution in pregnancy: weigh potential benefits against risks, as safety data are limited.
• Monitor for allergic reactions: discontinue if rash, swelling, or signs of hypersensitivity develop.
• Discontinue if severe neurotoxicity occurs: stop treatment if seizures or peripheral neuropathy appear.
• Store at ambient temperature: keep below 25 °C in the original packaging, protected from moisture and light.

Metronidazol Actavis can interact with other medicines, altering its efficacy or safety.

Major Interactions (Avoid)

• Alcohol: may cause a disulfiram‑like reaction with severe flushing, nausea and hypotension.
• Warfarin: potentiates anticoagulant effect, increasing risk of bleeding.
• Lithium: can raise lithium serum levels, leading to toxicity.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: may reduce hormonal efficacy, requiring additional contraceptive measures.
• Cimetidine: can increase metronidazole plasma concentrations, enhancing side effects.
• Theophylline: may raise theophylline levels, necessitating monitoring for toxicity.