Cardiovascular effects of ketanserin, a new antiserotonergic agent in the treatment of arterial hypertension.

Ketanserin, an investigational, antiserotonergic agent, at a dose of 40 mg bid was given to 18 patients with mild to moderate primary hypertension in a randomized, double-blind, crossover study, with 100-mg metoprolol bid for four weeks each. The following parameters were evaluated: blood pressure, heart rate, cardiac workload (product of systolic blood pressure and heart rate during bicycle exercise), systolic time intervals, and peripheral blood flow (by strain-gauge plethysmography). Significant reductions in diastolic and concomitant slight decreases in systolic blood pressure without changes in heart rate were observed during ketanserin treatment; cardiac oxygen demands during exercise test did not change, however. Pre-ejection period and left ventricular ejection time were unchanged, while significant increase in rest flow to the lower limbs and decrease in peripheral resistance were demonstrated by strain-gauge plethysmography. The results indicate that ketanserin has vasodilating properties and hypotensive activity that may be useful in the management of patients with essential hypertension.