Ondansetron

Also known as: Zofran (brand), 5-HT3 receptor antagonist antiemetic

Other

In plain English

Ondansetron is an anti-nausea and anti-vomiting medicine. It is used for nausea from chemotherapy, surgery/anesthesia, and other causes, and off-label for nausea in pregnancy and gastroenteritis. The dissolve-on-the-tongue tablet is convenient when swallowing is hard. It works well but can affect the heart's rhythm in susceptible people.

The science

Ondansetron selectively blocks serotonin 5-HT3 receptors both peripherally on gastrointestinal vagal afferents and centrally in the area postrema/chemoreceptor trigger zone and nucleus tractus solitarius, interrupting the emetic reflex; the peripheral action is considered predominant. It is a first-line antiemetic for chemotherapy-, radiation-, and post-operative nausea/vomiting but is not effective for motion sickness.

References

• Griddine A & Bush JS, Ondansetron, StatPearls (NCBI Bookshelf) 2023
• Antiemetics, Selective 5-HT3 Antagonists, StatPearls (NCBI Bookshelf)