Mechanism of action<unk>  is a 5-HT3 antagonist, commonly known as a setron. These drugs act by blocking serotonin from binding to the 5-HT3 receptor. Pharmacokinetics Orally taken<unk>  is absorbed well from the gut and has a bioavailability of 97%. Highest blood plasma levels are reached after 5.1±1.7 hours, independently of food intake, and plasma protein binding is 62%. 40% of the substance are eliminated in the unchanged form, and a further 45–50% are metabolized by the liver enzyme CYP2D6 and to a lesser extent by CYP3A4 and CYP1A2. The two main metabolites, the N-oxide and a hydroxy derivative, have less than 1% of<unk> 's antagonistic effect and are thus practically inactive.<unk>  and its metabolites are mainly (to 80–93%) eliminated via the kidney. Biological half-life in healthy persons was 37±12 hours in a study, and 48±19 hours in cancer patients. In 10% of patients, half-life is over 100 hours. Most other marketed setrons have half-lives in the range of about two to 15 hours. N-oxide (left) and 6S-hydroxy-palonosetron (right)
Palonosetron
Tropisetron
Alosetron
Granisetron
Cilansetron
Avacopan
Romidepsin
Tripelennamine