They have a potent antiemetic effect, acting primarily by blocking peripheral 5-HT3 receptors in the intestinal nerves, as well as affecting central receptors in the vomiting center and the chemoreceptor trigger zone.

The main antiemetic mechanism of action of these drugs is the blockade of dopaminergic receptors, which reduces esophageal and gastric motility.

Adverse reactions include euphoria, dysphoria, sedation, hallucinations, dry mouth, and increased appetite, and they may also cause autonomic effects such as tachycardia, conjunctival injection, and orthostatic hypotension.

The oral bioavailability of ondansetron is 65%, and due to its prolonged half-life, it allows for single-dose administration.