About ondansetron hydrochloride dihydrate
5-HT3 serotonin receptor antagonist
Used for
- Prevention and treatment of nausea and vomiting caused by chemotherapy
- Prevention of nausea and vomiting after surgery
- Treatment of nausea and vomiting caused by radiotherapy
Usual adult dose
Usually 8 mg by mouth before chemotherapy, then repeated as directed; dosing varies by cause and regimen.
Usual dose in children
For chemotherapy, usually 0.15 mg/kg per dose, up to 8 mg, on a scheduled regimen; specialist protocols vary.
Common side effects
- Headache
- Constipation
- Diarrhea
- Dizziness
Important warnings
- Can prolong the heart rhythm (QT interval), especially with heart conditions or low potassium or magnesium.
- Seek urgent care for fainting, a fast or irregular heartbeat, or signs of a severe allergic reaction.
- Rarely, may cause serotonin syndrome, particularly with other serotonin-raising medicines.
- May mask bowel blockage by reducing vomiting.
Pregnancy
Use only when clinically needed; discuss risks and benefits with a healthcare professional.
Breastfeeding
Information is limited; discuss use with a healthcare professional.
Interactions
- Apomorphine: combination is contraindicated because of severe low blood pressure and loss of consciousness.
- Other QT-prolonging medicines may increase abnormal heart rhythm risk.
- Serotonergic medicines may increase serotonin syndrome risk.
- Rifampicin, carbamazepine, or phenytoin 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 It may be incomplete or out of date.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.