Metronidazole Tablets

Metronidazole Tablets – MOA, Uses, Side Effect and Contraindication

Metronidazole Tablet, MOA of Metronidazole, Uses of metronidazole, Side Effect of Metronidazole, Contraindication of Metronidazole,

Metronidazole Tablet


When it comes to battling infections, metronidazole 400mg tablets are a crucial weapon in the medical arsenal. This article delves into the specifics of this versatile antibiotic, exploring its ADME (Absorption, Distribution, Metabolism, and Excretion), mode of action, uses, dosage, side effects, safety advice, contraindications, and top brands.

What is a Metronidazole Tablet?

Metronidazole is a nitroimidazole antibiotic commonly used to treat various infections. The 400mg tablet is one of the standard dosages available. It’s effective against anaerobic bacteria and certain parasites.

ADME of Metronidazole Tablet

Absorption: Metronidazole is well-absorbed orally, with peak plasma concentrations reached within one to two hours after ingestion.

Distribution: It is widely distributed in body tissues and fluids, including bile, bone, cerebrospinal fluid, liver, abscesses, and vaginal secretions.

Metabolism: The liver primarily metabolizes metronidazole, and the metabolites are also active against bacteria.

Excretion: Approximately 60-80% of the drug is excreted in urine, with a smaller amount excreted in feces.

Mode of Action of Metronidazole

Metronidazole works by entering the cells of anaerobic microorganisms and protozoa. Once inside, it disrupts their DNA synthesis, ultimately leading to cell death. This mechanism is particularly effective against bacteria and protozoa that thrive in low-oxygen environments.

Uses of Metronidazole Tablet

Bacterial Infections: It is used to treat infections like bacterial vaginosis, pelvic inflammatory disease, and certain types of bacterial gastroenteritis.

Protozoal Infections: Metronidazole is effective against infections caused by protozoa such as giardiasis, trichomoniasis, and amoebiasis.

Other Indications: It’s also prescribed for dental infections, rosacea, and certain skin infections due to its anti-inflammatory properties.

Dosage Guidelines of Metronidazole

Standard Dose: The typical dose for adults is 400mg taken two to three times daily, depending on the infection being treated.

Dose Adjustment: Dosage may need to be adjusted for patients with liver disease or severe renal impairment.

Duration of Treatment: Treatment usually lasts between 7 to 14 days but can be longer for more severe infections.

Side Effects of Metronidazole Tablet

Common Side Effects: These include nausea, a metallic taste in the mouth, and mild gastrointestinal discomfort.

Serious Side Effects: Rare but serious effects can include seizures, peripheral neuropathy, and severe allergic reactions.

Long-term Effects: Prolonged use may lead to neurotoxicity, so it’s crucial to follow the prescribed duration of therapy.

Safety Advice for Metronidazole Tablet

Usage Precautions: Avoid unnecessary sun exposure, as metronidazole can cause photosensitivity.

Interactions with Other Drugs: Metronidazole can interact with anticoagulants, lithium, and other medications, so inform your doctor about all the drugs you are taking.

Alcohol and Metronidazole: Consuming alcohol while taking metronidazole can lead to a disulfiram-like reaction, causing severe nausea, vomiting, and flushing.

Contraindications of Metronidazole

Absolute Contraindications: Do not use metronidazole if you have a known hypersensitivity to the drug or other nitroimidazole derivatives.

Relative Contraindications: Use with caution in patients with liver impairment, kidney dysfunction, or neurological conditions.

Top Brands of Metronidazole Tablet

Popular Brands: Some of the widely recognized brands include Metrogyl, Flagyl, Metro, and Nidazole. These brands are available globally and are trusted for their efficacy.

Availability: Metronidazole is widely available through pharmacies and can be obtained with a prescription.

Patient Experiences and Reviews

Positive Feedback: Many users report quick relief from symptoms of infection and appreciate its effectiveness.

Negative Feedback: Some users experience side effects like a metallic taste, nausea, or, in rare cases, more severe reactions.

Comparisons with Other Antibiotics

Metronidazole vs. Other Antibiotics: Compared to other antibiotics like penicillin or amoxicillin, metronidazole is particularly effective against anaerobic bacteria and protozoa. It is often used when other antibiotics are not suitable due to resistance or specific infection types.

Efficacy and Safety: Metronidazole is generally considered safe and effective, but it’s essential to follow the prescribed regimen and be aware of potential side effects and interactions.

FAQs about Metronidazole Tablet

  1. Can I drink alcohol while taking metronidazole?
    • No, consuming alcohol while on metronidazole can cause severe nausea and vomiting.
  2. What should I do if I miss a dose?
    • Take the missed dose as soon as you remember unless it’s almost time for your next dose. Do not double the dose.
  3. Can metronidazole treat viral infections?
    • No, metronidazole is effective against bacterial and protozoal infections, not viral infections.
  4. Is metronidazole safe during pregnancy?
    • Consult your doctor. Metronidazole can be used during pregnancy if the benefits outweigh the risks.
  5. What should I avoid while taking metronidazole?
    • Avoid alcohol and unnecessary sun exposure. Also, inform your doctor about any other medications you are taking.


Metronidazole 400mg tablets are a powerful antibiotic with a broad spectrum of uses against bacterial and protozoal infections. Understanding its ADME properties, mode of action, and proper usage can help ensure its effectiveness and safety. Always consult your healthcare provider for personalized advice and follow their guidelines closely to avoid potential side effects and interactions.

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