Serotonin receptors: clinical implications.

Over the past decade, a variety of serotonin (5-hydroxytryptamine, 5-HT) receptor/binding sites have been identified. These include 5-HT1, 5-HT2, and 5-HT3 sites. The 5-HT1 sites have been further divided into 5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D and 5-HT1E sites. It would be of interest to identify those pharmacological effects that are specifically mediated by a particular population of 5-HT sites and, indeed, attempts have been made to do this almost since the initial discovery of multiple populations of sites. Unfortunately, much of the early work made use of serotonergic agents that are now known to be somewhat less selective than originally suspected. Nevertheless, there is ample information in the literature suggesting that site-selective serotonergic agents may ultimately lead (and, in some cases, has already led) to the development of therapeutically-useful agents. The present review examines the pharmacological effects that are thought to be related to the individual types of 5-HT sites and provides some clinical implications for agents that act at these sites.