Ondansetron - Clinical Uses

Clinical Uses

The 5-HT₃ receptor antagonists are the primary drugs used to treat and prevent chemotherapy-induced nausea and vomiting (CINV). A common use case is to give them intravenously about 30 minutes before commencement of a chemotherapy treatment. Ondansetron is also effective in controlling post-operative nausea and vomiting (PONV) and post-radiation nausea and vomiting, and is a possible therapy for nausea and vomiting due to acute or chronic medical illness or acute gastroenteritis.

Although it is highly effective, the high cost of the brand-name version had limited its use to controlling PONV and CINV. It is also used off-label to treat hyperemesis gravidarum in pregnant women, but there is no conclusive data available on its safety in pregnancy, especially during the first trimester. It is also used to treat cyclic vomiting syndrome; although there have been no formal trials to confirm efficacy, case reports suggests it can be helpful in some cases. The drug is administered 1–3 times daily, depending on the severity of nausea and/or vomiting. The normal oral dose for adults and children over the age of 12 is 8 mg initially, followed by a second dose of 8 mg eight hours later. The drug is then administered once every 12 hours, usually for not more than 2–3 days. Following oral administration, it takes about 1.5 to 2 hours to reach maximum plasma concentrations. This drug is removed from the body by the liver and kidneys.

The clinical effect of ondansetron (and other drugs from the same group) can be potentiated by combining it with dexamethasone.