Antiemetics serotonin receptor antagonists

Greenshaw AJ, Silverstone PH. (1997). The non-antiemetic uses of serotonin 5-HT3 receptor antagonists. Clinical pharmacology and therapeutic applications. Drugs. 53(1) 20-39. 

Several different types of serotonin receptor (for example, S-HTi / 5-HT2A/ 5-HT2C/ 5-HTib/id) have been associated with the motor side effects of the SSRIs which may arise should these drugs be administered in conjunction with a monoamine oxidase inhibitor. The 5-HT3 receptor is an example of a non-selective cation charmel receptor which is permeable to both sodium and potassium ions and, because both calcium and magnesium ions can modulate its activity, the 5-HT3 receptor resembles the glutamate-NMDA receptor. Antagonists of the 5-HT3 receptor, such as ondansetron, are effective antiemetics and are particularly useful when... 

Neurokinin 1 (NKiJ-receptor antagonists have antiemetic properties that are mediated through central blockade in the area postrema. Aprepitant (an oral formulation) is a highly selective Nl -receptor antagonist that crosses the blood-brain barrier and occupies brain NKj receptors. It has no affinity for serotonin, dopamine, or corticosteroid receptors. Fosaprepitant is an intravenous formulation that is converted within 30 minutes after infusion to aprepitant. 

Ondansetron Alcohol Ondansetron is a serotonin 5-HT3 receptor antagonist, with low affinity for al-adrenergic, 5-HTiB, 5-HTiC, and J-opioid receptors [251]. It is used primarily to treat nausea and vomiting (antiemetic) following chemotherapy. 

Ondansetron is not a dopamine-receptor antagonist. Becanse serotonin receptors of the 5-HT3 type are present both peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone, it is not certain if ondansetron s antiemetic action is mediated centrally, peripherally, or in both sites (see Fignre 73). 

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],... 

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