Experience with Ketanserin and Ritanserin in Hypertensive Patients

In patients with essential hypertension, ketanserin (40 mg once or twice daily) reduces the blood pressure in mono- and combination therapy. Despite evidence of peripheral vasodilation, the heart rate is reduced. This would suggest that ketanserin has an additional sympathoinhibitory effect. However, the influence of ketanserin on plasma catecholamine levels at rest and during exercise or stress was small, and to date there is little evidence for a central sympathoinhibitory effect of ketanserin in humans. The antihypertensive effects of ritanserin, a selective 5-HT2-receptor antagonist, were investigated in a double-blind, placebo-controlled crossover study (4 weeks). Treatment with ritanserin, 10 mg twice daily, was ineffective in hypertensive patients, which indirectly suggests that the 5-HT2-blocking properties of ketanserin cannot alone be responsible for its antihypertensive effects.