Generic medicine

Metronidazole: Brands, Price & Uses in Bangladesh

Metronidazole is a nitroimidazole antimicrobial used to treat a range of anaerobic bacterial and protozoal infections.

Forms:TabletOral Suspension

About Metronidazole

Indications of Metronidazole

Metronidazole is a nitroimidazole antimicrobial used to treat a range of anaerobic bacterial and protozoal infections. Its indications can be grouped by strength of evidence:

Established/FDA-approved uses

  • Anaerobic bacterial infections of the abdomen, pelvis, skin/soft tissue, bone/joint, CNS, lower respiratory tract, and bloodstream caused by susceptible organisms (e.g., Bacteroides species, Clostridium species, Fusobacterium species, Peptococcus/Peptostreptococcus species).
  • Trichomoniasis (symptomatic and asymptomatic) in both male and female patients, including simultaneous treatment of sexual partners.
  • Intestinal amoebiasis and amoebic liver abscess caused by Entamoeba histolytica.
  • Surgical prophylaxis to reduce the incidence of postoperative infection in contaminated or potentially contaminated colorectal surgery.

Guideline-supported uses

  • Bacterial vaginosis.
  • Giardiasis (infection with Giardia duodenalis/lamblia).
  • Clostridioides difficile-associated diarrhea (mild-to-moderate disease per some guidelines, though vancomycin/fidaxomicin are now generally preferred first-line).

Adjunct/combination-therapy uses

  • Helicobacter pylori eradication, always used together with other antibiotics (e.g., clarithromycin or amoxicillin) and a proton pump inhibitor as part of a combination regimen — never as monotherapy for this indication.

Off-label uses (commonly used, not FDA-approved for this route/form)

  • Certain dermatologic conditions such as rosacea (topical formulations); use only on a physician's advice.

Dosage & Administration of Metronidazole

Dosage of Metronidazole must be individualized according to the indication, patient age, weight, and renal/hepatic function. Take Metronidazole exactly as prescribed by your physician; do not stop, extend, skip doses, or share this medicine with others without medical advice.

Adult dosing by indication

IndicationTypical adult doseDuration
Anaerobic bacterial infections7.5 mg/kg (usually 500 mg) orally or IV every 6-8 hours (maximum 4 g/24 hours)7-10 days (longer for bone/joint, endocardial, or CNS infections)
Trichomoniasis2 g single oral dose, or 250 mg three times daily, or 375 mg twice dailySingle dose or 7 days; sexual partners should be treated simultaneously
Intestinal amoebiasis500-750 mg orally three times daily5-10 days
Amoebic liver abscess500-750 mg orally three times daily5-10 days, often followed by a luminal amoebicide
Bacterial vaginosis500 mg orally twice daily, or intravaginal gel once daily7 days
Giardiasis250 mg orally three times daily5-7 days
H. pylori eradication (combination therapy)400-500 mg orally two or three times daily, combined with other antibiotics and a proton pump inhibitor10-14 days, per regimen
Surgical prophylaxisPer institutional protocol, typically 500 mg-1 g IV before surgerySingle perioperative dose or short course

Pediatric dosing

Pediatric dosing is weight-based and indication-specific (e.g., approximately 35-50 mg/kg/day in three divided doses for amoebiasis; lower doses for giardiasis). See Use in Special Populations and Pediatric Uses for details; a pediatrician should determine the exact dose.

Renal/hepatic adjustment

No dose adjustment is generally needed for mild-to-moderate renal impairment; dose reduction may be considered in severe renal impairment or hemodialysis (a supplemental dose may be needed after dialysis). In severe hepatic impairment, reduced doses and close monitoring are recommended because Metronidazole is extensively metabolized by the liver.

Side Effects of Metronidazole

Common side effects of Metronidazole include:

  • Metallic or bitter taste in the mouth (common, benign)
  • Nausea, vomiting, loss of appetite, abdominal discomfort/cramping
  • Diarrhea
  • Headache and dizziness
  • Dry mouth or glossitis (furry tongue)
  • Darkened (reddish-brown) urine — harmless

Less common but important effects:

  • Peripheral neuropathy (numbness, tingling in hands/feet) and CNS effects such as seizures and encephalopathy — rare, generally associated with prolonged or high-dose Metronidazole therapy; discontinue Metronidazole and seek medical attention if neurological symptoms occur (see Precautions and Warnings).
  • Clostridioides difficile-associated diarrhea/colitis, ranging from mild diarrhea to severe colitis, which can occur during or after Metronidazole treatment.
  • Rash, urticaria, and rarely severe hypersensitivity reactions.
  • Leukopenia (usually reversible).

Contraindications of Metronidazole

Metronidazole is contraindicated in:

  • Patients with known hypersensitivity to Metronidazole or other nitroimidazole derivatives.
  • Patients using disulfiram, or who have used disulfiram within the preceding two weeks.
  • First trimester of pregnancy for the treatment of trichomoniasis, per some prescribing guidance (consult specific product labeling and a physician); see Pregnancy and Lactation for use later in pregnancy.

Frequently Asked Questions about Metronidazole

What is Metronidazole used for?

Metronidazole is used to treat anaerobic bacterial infections, certain protozoal infections such as amoebiasis, giardiasis and trichomoniasis, bacterial vaginosis, and as part of combination therapy for H. pylori eradication and surgical infection prevention.

Can I drink alcohol while taking Metronidazole?

No. Alcohol should be avoided during treatment with Metronidazole and for at least 24-72 hours after the last dose, as combining them can cause a disulfiram-like reaction with flushing, nausea, vomiting, headache, and a fast heartbeat.

Is it safe to take Metronidazole during pregnancy?

Metronidazole should be used in pregnancy only if clearly needed and if the potential benefit outweighs the potential risk to the fetus, and only under a physician's guidance; Metronidazole is generally avoided in the first trimester for trichomoniasis treatment. Always consult your physician before taking Metronidazole during pregnancy.

Why does my urine look dark after taking Metronidazole?

Metronidazole can cause the urine to appear darker or reddish-brown. This is a harmless effect and resolves after Metronidazole is stopped, but tell your physician if you are concerned.

What should I do if I miss a dose of Metronidazole?

Take the missed dose of Metronidazole as soon as you remember, unless it is almost time for the next dose, in which case skip the missed dose and continue your regular schedule. Do not double the dose. Always complete the full course of Metronidazole exactly as prescribed by your physician.

What are the serious warning signs to watch for while taking Metronidazole?

Seek immediate medical attention if you develop numbness or tingling in your hands or feet, confusion, seizures, severe or persistent diarrhea, or signs of an allergic reaction while taking Metronidazole, as these may indicate rare but serious side effects.

Disclaimer

The information provided is accurate to the best of our knowledge, but it does not replace professional medical advice. We cannot guarantee its completeness or accuracy, and the absence of specific information about a drug should not be taken as an endorsement. We are not responsible for any consequences arising from this information, so please consult a healthcare professional for any concerns or questions.

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