Vomiting serotonin antagonists

The serotonin antagonist ondansetron (Zofran) has proved effective in the prevention of nausea and vomiting due to chemotherapy. 

Bemesetron is a synthetic ester of tropine and dichlorobenzoylic acid (Fig. 1). In contrast to TA introduced above, bemesetron primarily acts as a selective serotonin antagonist on the 5-HT3R in the CNS and GIT. Therefore, it was tested as an injectable antiemetic drug for cancer chemotherapy to treat vomiting and nausea but is not in clinical use [36, 37, 58],... 

The most widely used emetic is syrup of ipecac, containing the alkaloids, emetine and cq haeline. Emetine induces vomiting by activation of sensory neurons in the vagus and sympathetic nerves to the stomach and centrally in the medulla, possibly at the CTZ. The release of serotonin and SP may be involved as 5-HT3 and NKi receptor antagonists prevent emesis induced... 

Release of SP from neurons in the AP, NTS and dorsal vagal motor nucleus may play a role in vomiting induced by cytotoxics. Based on the relative effectiveness of selective antagonists of 5-HT3 receptors and NKi receptors against acute and delayed phases of cisplatin-induced vomiting, it has been suggested that serotonin has a greater role in the acute phase whereas SP has the major role in the delayed phase. 

This discussion will be limited to the neural serotonin 5-HT3 receptors which came to the forefront with the advent of antiemetic agents exhibiting 5-HT3 antagonist properties. At the present time, there is no evidence that 5-HT, and 5-HT2 receptors play an important role in vomiting [64],... 

Ondansetron is a 5HT3 antagonist, blocking serotonin receptors in the central nervous system and the gastrointestinal tract. It is useful in the management of postoperative nausea and vomiting associated with cytotoxics. 

Use selective blocking of serotonin 5-HT3 receptors or use 5-HT3 receptor antagonists to treat vomiting. 

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