Treatment of pruritus: a new indication for serotonin type 3 receptor antagonists.

Generalized pruritus is a well-known, distressing symptom of various diseases, especially in hepatic cholestasis and chronic renal insufficiency. Its treatment is often unsatisfactory. In three patients with generalized pruritus, intravenous administration of the serotonin type 3 (5-HT3) receptor antagonist ondansetron induced a marked relief of itching. The effect was most pronounced in a patient with cholestasis-associated pruritus. It is suggested that serotonin, acting via 5-HT3 receptors, is involved in the generation and/or sensation of pruritus. Furthermore, 5-HT3 receptor antagonists may be a novel therapeutic principle for the treatment of pruritus.