Ornidazole
Ornidazole is a anti-amoebic and antibacterial found in 15 medicines sold in India, such as O2, Oflox-OZ, Zenflox-OZ. 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, giardia and some gut infections.
How it works
A nitroimidazole that kills amoebas, giardia and anaerobic bacteria; often combined with ofloxacin for diarrhoea.
How to take it
Usually 500 mg twice a day after food for 5 to 10 days.
Common side effects
- Metallic taste
- Nausea
- Dizziness
- Headache
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.
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
Avoid in the first three months of pregnancy; ask a doctor about breastfeeding.
Combination medicines that contain Ornidazole (15)
Common questions
What is Ornidazole used for?
Treats amoebic dysentery, giardia and some gut infections.
How does Ornidazole work?
A nitroimidazole that kills amoebas, giardia and anaerobic bacteria; often combined with ofloxacin for diarrhoea.
How should I take Ornidazole?
Usually 500 mg twice a day after food for 5 to 10 days.
What are the side effects of Ornidazole?
Common: Metallic taste, nausea, dizziness, headache. Get help straight away for: Numbness or tingling in hands or feet, fits, severe diarrhoea, dark urine with yellow skin.
Does Ornidazole 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 Ornidazole safe in pregnancy and breastfeeding?
Avoid in the first three months of pregnancy; ask a doctor about breastfeeding.
Does Ornidazole 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 Ornidazole?
Brakke, Nicoflox-O, Nor Metrogyl Plus, Normet, O2, Oflomac OZ, Oflotas OZ, Oflox-OZ, Olox OZ, Ordent, Orni-O, Ornof, Saril, Zanocin OZ, Zenflox-OZ.
Sources and further reading
- Ornidazole: 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.
🔎 Search another medicine