Alosetron: ischemic colitis and serious complications of constipation.

Drugs such as alosetron that modulate serotonin effects by stimulating or blocking its receptors may play an important role in the treatment of some patients with irritable bowel system. In the case of alosetron, a 5HT-3 antagonist, an analysis of data from randomized clinical trials and postmarketing experiences have demonstrated a causal relationship between this drug and ischemic colitis and serious complications of constipation. Because the mechanism(s) of drug-induced ischemic colitis and possibly other forms of intestinal ischemia associated with alosetron have not been elucidated, there is need to further assess risk with regard to patient susceptibility and other factors.