5-HT3 antagonist

5-HT3 receptor antagonist
Drug class
Skeletal formula of ondansetron, the prototypical 5-HT3 antagonist
Class identifiers
Use	Nausea and Vomiting
ATC code	A04AA
Biological target	5-HT3 receptor
Clinical data
Drugs.com	Drug Classes
Consumer Reports	Best Buy Drugs
External links
MeSH	D058831

The 5-HT₃ antagonists, informally known as "setrons", are a class of drugs that act as receptor antagonists at the 5-HT₃ receptor, a subtype of serotonin receptor found in terminals of the vagus nerve and in certain areas of the brain. With the notable exceptions of alosetron and cilansetron, which are used in the treatment of irritable bowel syndrome, all 5-HT₃ antagonists are antiemetics, used in the prevention and treatment of nausea and vomiting. They are particularly effective in controlling the nausea and vomiting produced by cancer chemotherapy and are considered the gold standard for this purpose.

The 5-HT₃ antagonists may be identified by the suffix -setron, and are classified under code A04AA of the WHO's Anatomical Therapeutic Chemical Classification System.

5-HT₃ antagonists are most effective in the prevention and treatment of chemotherapy-induced nausea and vomiting (CINV), especially that caused by highly emetogenic drugs such as cisplatin; when used for this purpose, they may be given alone or, more frequently, with a glucocorticoid, usually dexamethasone. They are usually given intravenously, shortly before administration of the chemotherapeutic agent, although some authors have argued that oral administration may be preferred. The concomitant administration of a NK₁ receptor antagonist, such as aprepitant, significantly increases the efficacy of 5-HT₃ antagonists in preventing both acute and delayed CINV.