Anatomical Therapeutic Chemical Classification System
Dolasetron and its active metabolite, hydrodolasetron (MDL 74,156), are selective serotonin 5-HT3 receptor antagonists not shown to have activity at other known serotonin receptors and with low affinity for dopamine receptors. The serotonin 5-HT3 receptors are located on the nerve terminals of the vagus in the periphery and centrally in the chemoreceptor trigger zone of the area postrema.
Granisetron is a potent anti-emetic and highly selective antagonist of 5-hydroxytryptamine (5HT3 receptors). Pharmacological studies have demonstrated that granisetron is effective against nausea and vomiting as a result of cytostatic therapy.
Netupitant is a selective antagonist of human substance P/neurokinin 1 (NK1) receptors. Delayed emesis has been associated with the activation of tachykinin family neurokinin 1 (NK1) receptors (broadly distributed in the central and peripheral nervous systems) by substance P. As shown in in vitro and in vivo studies, netupitant inhibits substance P mediated responses.
Ondansetron is a potent, highly selective 5HT3 receptor-antagonist. Its precise mode of action in the control of nausea and vomiting is not known.
Palonosetron is a selective high-affinity receptor antagonist of the 5HT3 receptor.
Tropisetron is a highly potent and selective competitive antagonist of the 5-HT3 receptor. Tropisetron selectively blocks the excitation of the presynaptic 5-HT3 receptors of the peripheral neurons in this reflex, and may exert additional direct actions within the CNS on 5-HT3 receptors mediating the actions of vagal input to the area postrema.