Metronidazole — Drug Interactions, Alcohol & Pregnancy Guide
Last reviewed: · Source: US FDA drug label database · 247CanITakeWith Editorial Team
- Metronidazole is a Nitroimidazole antibiotic / antiprotozoal used for Bacterial vaginosis.
- Alcohol: Never drink alcohol with metronidazole — the combination causes a severe disulfiram-like reaction with vomiting, flushing, rapid heart rate, and severe distress.
- Pregnancy: Metronidazole is avoided in the first trimester by convention, but can be used later in pregnancy when needed — bacterial vaginosis must be treated.
About Metronidazole
Metronidazole is an antibiotic used for anaerobic bacterial and protozoal infections. CRITICAL: it causes a severe disulfiram-like reaction with alcohol (intense vomiting, flushing, rapid heart rate). Avoid all alcohol for 48 hours after the last dose.
Also sold as: Flagyl, Metrogel, Rozex
Metronidazole at a glance
Metronidazole is classed as nitroimidazole antibiotic / antiprotozoal and is used for bacterial vaginosis, dental infections, c. difficile, h. pylori eradication, protozoal infections. It is a prescription medicine, so doses and combinations should always be agreed with your prescriber or pharmacist.
Typical adult dosing guidance: 400mg twice daily for most infections; 200-500mg three times daily depending on indication. Your own label or prescription always takes priority over general figures.
Interactions most often flagged
- Alcohol
- Pregnancy
- Warfarin
Before you combine Metronidazole with anything new
- Read the patient information leaflet for both products.
- Keep one up-to-date list of every medicine and supplement you take.
- Ask a pharmacist — it is free and takes a couple of minutes.
- Seek urgent medical help if you feel seriously unwell after combining medicines.
Metronidazole and Alcohol
Never drink alcohol with metronidazole — the combination causes a severe disulfiram-like reaction with vomiting, flushing, rapid heart rate, and severe distress.
Full guide →Metronidazole in Pregnancy
Metronidazole is avoided in the first trimester by convention, but can be used later in pregnancy when needed — bacterial vaginosis must be treated.
Full guide →More in this category: antibiotics
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Frequently Asked Questions
What is Metronidazole used for?
Metronidazole is a Nitroimidazole antibiotic / antiprotozoal used for Bacterial vaginosis, Dental infections, C. difficile, H. pylori eradication, Protozoal infections.
What is the maximum adult dose of Metronidazole?
The maximum adult dose is 400mg twice daily for most infections; 200-500mg three times daily depending on indication. This is general guidance — always follow the dose on your prescription or product label, and check with a pharmacist if you're unsure.
Can I drink alcohol with Metronidazole?
Never drink alcohol with metronidazole — the combination causes a severe disulfiram-like reaction with vomiting, flushing, rapid heart rate, and severe distress.
Is Metronidazole safe to take during pregnancy?
Metronidazole is avoided in the first trimester by convention, but can be used later in pregnancy when needed — bacterial vaginosis must be treated.
Is Metronidazole available over the counter in the UK?
Metronidazole is prescription-only in the UK.
What should I check before taking Metronidazole with other medicines?
The interactions most often flagged for Metronidazole are: alcohol, pregnancy, warfarin. Tell your pharmacist or prescriber about everything you take, including over-the-counter products, supplements and herbal remedies, before combining it with anything new.
What are the brand names for Metronidazole?
Metronidazole is sold under brand names including Flagyl, Metrogel, Rozex. The active ingredient is the same, so check labels carefully to avoid doubling up on it.
Do I need a prescription for Metronidazole?
Metronidazole is a prescription medicine, so take it exactly as your prescriber directed and ask them before changing the dose.
Not sure if Metronidazole is safe with your other medications?
HealthLabs.com lets you check liver enzyme or kidney function levels before combining medications long-term — no GP referral needed.
Check your levels at HealthLabs →Always speak to your pharmacist or GP for personalised medical advice. Affiliate link — we may earn a commission.