Ondansetron

DB00904ApprovedInvestigationalWithdrawnSmall moleculeAntiemetics Serotonin 5-HT3 Receptor Antagonists

Ondansetron is a serotonin 5-HT3 receptor antagonist used to prevent nausea and vomiting in cancer chemotherapy and postoperatively. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties.

Mechanism: Ondansetron is a selective antagonist of the serotonin receptor subtype, 5-HT3.
Cytotoxic chemotherapy and radiotherapy are associated with the release of serotonin (5-HT) from enterochromaffin cells of the small intestine, presumably initiating a vomiting reflex through stimulation of 5-HT3 receptors located on vagal afferents. Ondansetron may block the initiation of this reflex. Activation of vagal afferents may also cause a central release of serotonin from the chemoreceptor trigger zone of the area postrema, located on the floor of the fourth ventricle. Thus, the antiemetic effect of ondansetron is probably due to the selective antagonism of 5-HT3 receptors on neurons located in either the peripheral or central nervous systems, or both.
Although the mechanisms of action of ondansetron in treating postoperative nausea and vomiting and cytotoxic induced nausea and vomiting may share similar pathways, the role of ondansetron in opiate-induced emesis has not yet been formally established.
Curator reviewed · 14 references
Primary indication: In the adult patient population: i) orally administered ondansetron tablets and orally disintegrating tablets (ODT) are indicated for: - the prevention of nausea and vomiting associated with emetogenic cancer chemotherapy, including high dose (ie. greater...Curator reviewed · 7 structured indications
Formula / weight: C₁₈H₁₉N₃O · 293.363 g/mol (avg)
First approval: Canada, 2006 · United States, 1991
Brand names: Zofran
Zuplenz