About ondansetron usp
Serotonin 5-HT3 receptor antagonist
Used for
- Prevents nausea and vomiting caused by chemotherapy
- Prevents nausea and vomiting after surgery
- Treats nausea and vomiting from radiotherapy
Usual adult dose
Commonly 8 mg by mouth; dose and timing depend on the cause. Follow the prescribed regimen.
Usual dose in children
For chemotherapy-related nausea, typically 0.15 mg/kg per dose, up to three doses; maximum 8 mg per dose. Age and regimen matter.
Common side effects
- Headache
- Constipation or diarrhea
- Tiredness
- Dizziness
Important warnings
- Can cause serious heart-rhythm changes, especially with long QT syndrome or low potassium or magnesium.
- Seek urgent care for allergic reactions or fainting.
- May mask signs of bowel blockage.
- Use caution with severe liver disease; maximum daily dose may need limiting.
Pregnancy
Often used when needed for pregnancy-related nausea, but discuss benefits and risks with a clinician.
Breastfeeding
Small amounts may enter breast milk; available information suggests low risk, but consult a clinician.
Interactions
- Apomorphine: combination is contraindicated due to severe low blood pressure and loss of consciousness risk.
- Other medicines that prolong the QT interval can increase abnormal heart-rhythm risk.
- Serotonergic medicines may increase risk of serotonin syndrome.
- Some enzyme-inducing medicines, such as carbamazepine or rifampin, may reduce effectiveness.
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 It may be incomplete or out of date.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.