Metronidazole
Metronidazole is a anti-amoebic and antibacterial found in 2 medicines sold in India, such as Flagyl 400, Metrogyl 400. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.
What it is used for
Treats amoebic dysentery, gut, dental and vaginal infections.
How it works
A nitroimidazole for amoebic and giardia infections, bacterial vaginosis, dental abscesses and anaerobic infections, including C. difficile.
How to take it
Usually 400 mg two or three times a day with or after food, for 5 to 7 days.
Common side effects
- Metallic taste
- Nausea
- Dark urine
- Loss of appetite
Get medical help straight away if
- Numbness or tingling in hands or feet
- Fits
- Severe diarrhoea
- Dark urine with yellow skin
Be careful
Avoid alcohol during and for 2 days after the course; metallic taste is common.
Other medicines and interactions
Do not drink alcohol during the course and for 3 days after (severe flushing, vomiting and palpitations). Strengthens warfarin; can raise lithium levels.
Pregnancy and breastfeeding
Can be used in pregnancy when needed (high single doses avoided). Passes into breast milk; a doctor may advise a short pause after single high doses.
Brands of Metronidazole (2)
Common questions
What is Metronidazole used for?
Treats amoebic dysentery, gut, dental and vaginal infections.
How does Metronidazole work?
A nitroimidazole for amoebic and giardia infections, bacterial vaginosis, dental abscesses and anaerobic infections, including C. difficile.
How should I take Metronidazole?
Usually 400 mg two or three times a day with or after food, for 5 to 7 days.
What are the side effects of Metronidazole?
Common: Metallic taste, nausea, dark urine, loss of appetite. Get help straight away for: Numbness or tingling in hands or feet, fits, severe diarrhoea, dark urine with yellow skin.
Does Metronidazole interact with other medicines?
Do not drink alcohol during the course and for 3 days after (severe flushing, vomiting and palpitations). Strengthens warfarin; can raise lithium levels.
Is Metronidazole safe in pregnancy and breastfeeding?
Can be used in pregnancy when needed (high single doses avoided). Passes into breast milk; a doctor may advise a short pause after single high doses.
Does Metronidazole need a prescription in India?
Yes. In India it is a prescription (Schedule H) medicine, so a pharmacist should sell it only with a doctor's prescription.
Which brands contain Metronidazole?
Flagyl 400, Metrogyl 400.
Sources and further reading
- Metronidazole: NHS · MedlinePlus
NHS (UK National Health Service) and MedlinePlus (US National Library of Medicine) are free, reviewed medicine guides. Brand names and doses there may differ from India.
Last reviewed 31 October 2026. Written by Satya Babu from standard prescribing information.
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