Ondansetron

Anti-vomiting
PRESCRIPTION ONLY IN INDIA

Ondansetron is a anti-vomiting found in 18 medicines sold in India, such as Ondem 4, Emeset, Ondem MD 4. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.

What it is used for

Prevents and treats nausea and vomiting.

How it works

It blocks serotonin (5-HT3) receptors in the gut and brain that trigger vomiting. Widely used for vomiting from stomach bugs, chemotherapy and surgery.

How to take it

Usually 4 to 8 mg up to two or three times a day; dissolving tablets melt on the tongue. Children's doses go by weight.

Common side effects

  • Headache
  • Constipation
  • Feeling of warmth or flushing
  • Tiredness

Get medical help straight away if

  • Fast or irregular heartbeat or fainting
  • Agitation, fever and shaking (serotonin syndrome)
  • Allergic swelling

Be careful

Can cause constipation or headache.

Other medicines and interactions

Risk of heart rhythm problems with other QT-prolonging medicines. Serotonin syndrome risk with SSRIs, SNRIs and tramadol. Do not take with apomorphine.

Pregnancy and breastfeeding

Doctors may use it in pregnancy for severe vomiting after weighing a small possible risk in the first three months. Considered acceptable while breastfeeding.

Brands of Ondansetron (18)

EmesetEmeset InjectionEmeset-4 ODTEmigo MDEterna MD 4Nuavomin-4Ondem 4Ondem 8Ondem InjectionOndem MD 4Onvin 4 MDPeriset MDVomiford-4 MDVomikind 4Vomikind MD 4Vominil-MD 4Zofer 4Zofer MD 4

Common questions

What is Ondansetron used for?

Prevents and treats nausea and vomiting.

How does Ondansetron work?

It blocks serotonin (5-HT3) receptors in the gut and brain that trigger vomiting. Widely used for vomiting from stomach bugs, chemotherapy and surgery.

How should I take Ondansetron?

Usually 4 to 8 mg up to two or three times a day; dissolving tablets melt on the tongue. Children's doses go by weight.

What are the side effects of Ondansetron?

Common: Headache, constipation, feeling of warmth or flushing, tiredness. Get help straight away for: Fast or irregular heartbeat or fainting, agitation, fever and shaking (serotonin syndrome), allergic swelling.

Does Ondansetron interact with other medicines?

Risk of heart rhythm problems with other QT-prolonging medicines. Serotonin syndrome risk with SSRIs, SNRIs and tramadol. Do not take with apomorphine.

Is Ondansetron safe in pregnancy and breastfeeding?

Doctors may use it in pregnancy for severe vomiting after weighing a small possible risk in the first three months. Considered acceptable while breastfeeding.

Does Ondansetron 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 Ondansetron?

Emeset, Emeset Injection, Emeset-4 ODT, Emigo MD, Eterna MD 4, Nuavomin-4, Ondem 4, Ondem 8, Ondem Injection, Ondem MD 4, Onvin 4 MD, Periset MD, Vomiford-4 MD, Vomikind 4, Vomikind MD 4, Vominil-MD 4, Zofer 4, Zofer MD 4.

Sources and further reading

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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For information only, not medical advice. This page is a plain-language summary written from standard prescribing information and the public guides linked below. Brands sometimes change their formula, so always check the composition printed on the pack. Doses here are typical adult doses; yours may differ. Do not start, stop or change a medicine without your doctor or pharmacist, and keep all medicines away from children. In an emergency, call 112 (India) or your local emergency number.