Long-term antihypertensive efficacy of ketanserin plus chlorthalidone

The long-term antihypertensive efficacy of a combination of ketanserin (20 mg), an S2 antagonist with alpha 1 blocking activity, and chlorthalidone (25 mg), given o.d., was evaluated in fifteen patients with primary hypertension of mild to moderate degree, aged 45-65 years, up to a 12-month observation period. Systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) were measured by an automatic recorder (Sentron Bard Biomedical) twice at rest after 5 min in a supine position and after 2 and 5 min in an upright position, 24 h after the last antihypertensive dose. Thirteen patients completed the study whilst two were lost to the follow-up. A significant reduction was observed in both SBP and DBP at rest. In particular, SBP was reduced from 167 +/- 17 mmHg to 152 +/- 21 mmHg (p less than 0.01) after 1 month of therapy and was kept constant at this level throughout the observation period. DBP was also reduced from the first control [99 +/- 7 vs. 90 +/- 9 mmHg (p less than 0.01)] without any increase during the follow-up. HR was unchanged throughout the study. Four patients had dizziness and orthostatic hypotension after the first dose of the drug combination but were able to continue the study without further adverse reactions. These data support the conclusion that long-term treatment with the combination of a small dose of ketanserin and chlorthalidone is able to reduce systolic and diastolic blood pressure, without remarkable untoward side-effects.