Placebo-controlled, double-blind, two-centre trial of ketanserin in intermittent claudication.

The effects of ketanserin, a serotonin antagonist, were studied in 37 patients with intermittent claudication in a double-blind placebo-controlled, trial done in London and Leuven. 40 mg ketanserin taken orally three times a day for 4 months was associated with a clear-cut inhibition of serotonin-induced platelet aggregation but no changes were observed in pain-free and maximum walking distance on a treadmill, in ankle/arm Doppler systolic blood pressure ratio, or in reactive hyperaemia after 3 min of ischaemia. In contrast, the placebo group had increases in both pain-free and maximum walking distance (p less than 0.05).