Evaluation of a new antihypertensive agent ketanserin versus methyldopa in the treatment of essential hypertension in older patients: an international multicenter trial.

The serotonergic antagonist ketanserin (K) was compared to methyldopa (M) in a four-center international study in 119 hypertensive patients over 50 years of age. After a 4-week placebo run-in period, patients randomly received K (20-40 mg b.i.d.) or M (250-500 mg b.i.d.) for 3 months. The drugs were given in monotherapy for at least 1 month, then a diuretic could be added if blood pressure remained abnormally high. For the patients on monotherapy, active drug was replaced by placebo at the end of the 3-month period until the patients were hypertensive again. K and M had a similar effect on systolic blood pressure, but diastolic blood pressure was reduced significantly more by K than by M. Significantly more patients had their blood pressure normalized in the K group (75%) than in the M group (49%). The twice daily dosage schedule caused trough blood pressure control with both drugs. No rebound hypertension occurred at discontinuation of treatment. Monotherapy with K caused a decrease in heart rate (-5 beats/min) while M produced no change. Body weight decreased with K (-0.5 kg) and increased with M (+ 0.4 kg). No important hematological or biochemical changes were seen with either drug. Slightly fewer patients reported adverse reactions during K monotherapy (40%) than with M (45%). In the latter group mainly central side effects were observed. The data confirm K to be an effective first-line antihypertensive agent with a favorable side-effect profile.