About ondansetron
5-HT3 receptor antagonist antiemetic
Used for
- Prevention and treatment of nausea and vomiting from chemotherapy
- Prevention and treatment of nausea and vomiting after surgery
- Treatment of nausea and vomiting related to radiotherapy
Usual adult dose
Usually 4–8 mg by injection for postoperative nausea; chemotherapy doses vary by regimen, commonly 8–16 mg.
Usual dose in children
For children aged 1 month and older after surgery, usually 0.1 mg/kg by injection, maximum 4 mg. Chemotherapy dosing is weight- or surface-area-based.
Common side effects
- Headache
- Constipation or diarrhoea
- Dizziness
- Injection-site reactions
Important warnings
- Can prolong the heart rhythm (QT); risk is higher with certain conditions or medicines.
- Avoid with apomorphine because severe low blood pressure and loss of consciousness may occur.
- Use caution with bowel obstruction, as it may mask worsening symptoms.
- Rarely causes serotonin syndrome, especially with other serotonergic medicines.
Pregnancy
Use only when clinically needed; safety information is limited, particularly early in pregnancy.
Breastfeeding
Small amounts may enter breast milk; discuss use with a healthcare professional.
Interactions
- Apomorphine: contraindicated combination.
- QT-prolonging medicines may increase abnormal heart rhythm risk.
- Serotonergic medicines may increase serotonin syndrome risk.
- Rifampicin and other enzyme-inducing medicines may reduce ondansetron effects.
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 It may be incomplete or out of date.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.