Oral dosing with ketanserin to control high blood pressure in the elderly.

Ketanserin is the prototype of a new class of antihypertensive drugs based on a selective blockade of serotonin S2 receptors. A number of controlled trials have indicated that ketanserin is more effective in older than in younger subjects and that, in the elderly, ketanserin may be even more effective than other antihypertensive drugs. We set up a large multicenter trial to compare the two most common dosages of ketanserin (20 mg and 40 mg twice daily) in patients of 60 years of age and over. In these patients, blood pressures were elevated systolically (SBP greater than or equal to 160 mmHg), diastolically (DBP greater than or equal to 95 mmHg), or both, and any existing antihypertensive medication was continued at a constant dosage. The total duration of the trial was 3 months and monthly control visits were held. Throughout the Netherlands, 252 general practitioners participated in the trial, which included 462 evaluable patients. After 1 month of open treatment with 20 mg ketanserin twice daily, blood pressure was found to be fully normalized in 18% of patients, while the proportion of patients with both systolic and diastolic hypertension was reduced from 89% to 50%. In three out of four patients, an adequate and maximal fall in blood pressure was reached only after 2-3 months of treatment. In such patients, raising the ketanserin dose from 20 mg to 40 mg twice daily did not result in any faster or improved antihypertensive response. A number of symptoms related to peripheral circulatory disturbances, or possibly to hypertension itself, markedly improved during oral treatment with ketanserin.