Diarrhea, treatment specific agents

Many reports have linked childhood hyperactivity to impaired central serotonin functions.89 In animals, the occurrence of a behavioral syndrome consisting of hyperactivity, stereotyped movements, and increase of temperature has been induced by L-tryptophan, as a serotonin precursor, by serotonin reuptake inhibitors, and by MAOIs.90 Most of these manifestations can be blocked specifically by pretreatment with an inhibitor of serotonin synthesis. In humans, the association of myoclonus, diarrhea, confusion, hypomania, agitation, hyperreflexia, shivering, incoordination, fever, and diaphoresis, when patients are treated with serotoninergic agents, could constitute a "serotonin syndrome." Such cases of serotonin syndrome were reported after treatments with L-tryptophan, MAOIs, serotonin reuptake inhibitors, and tricyclics, alone or in association. 

HT4 agonists such as tegaserod. Although they also may blunt visceral sensation, a direct effect on spinal afferents has not been fully established. Alosetron was the first agent in this class specifically approved for the treatment of diarrhea-predominant IBS in women. 

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