About ondansetron
Serotonin 5-HT3 receptor antagonist
Used for
- Prevention and treatment of nausea and vomiting caused by chemotherapy
- Prevention of nausea and vomiting after surgery
- Prevention of nausea and vomiting caused by radiotherapy
Usual adult dose
Usually 4–8 mg by slow injection, depending on the cause and treatment protocol.
Usual dose in children
Chemotherapy: commonly 0.15 mg/kg intravenously per dose, up to 8 mg; dosing depends on age and protocol.
Common side effects
- Headache
- Constipation or diarrhoea
- Flushing
- Injection-site reactions
Important warnings
- May prolong the heart’s electrical rhythm, especially with risk factors or high doses.
- Use caution with abnormal heart rhythms, low potassium, or low magnesium.
- Can mask signs of bowel obstruction.
- Rarely causes severe allergic reactions or serotonin syndrome.
Pregnancy
Use when clinically needed; pregnancy safety evidence is limited.
Breastfeeding
Information is limited; discuss potential use with a healthcare professional.
Interactions
- Apomorphine: combination is contraindicated due to severe low blood pressure and loss of consciousness.
- Other medicines that prolong the QT interval can increase heart-rhythm risks.
- Serotonergic medicines may increase the risk of serotonin syndrome.
- Some enzyme-inducing medicines, such as rifampicin, may reduce ondansetron levels.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.