The use of the selective serotonin S2 receptor antagonist Ketanserin in the treatment of Raynaud's phenomenon.

Ketanserin, a selective S2-receptor antagonist was evaluated in a double-blind parallel placebo-controlled trial of 29 patients with Raynaud's phenomenon. The effect on finger blood flow was assessed by strain-gauge plethysmography during a standardised cooling stress. Ten normal healthy controls also had finger blood flow assessments made in the same way. The Ketanserin group showed a significantly greater improvement (P less than 0.05) in finger blood flow at minimum flow temperature than the placebo group. The results suggest that the local release of serotonin may play a role in Raynaud's phenomenon and that Ketanserin can modify the abnormal response in finger blood flow.