RESULTS OF COMBINATION ANTIHYPERTENSIVE THERAPY AFTER FAILURE OF EACHOF THE COMPONENTS

We randomised ambulatory men with diastolic blood pressure (BP) 95-109 mm Hg without anti-hypertensive medication to single drug treatment w ith either hydrochlorothiazide 12.5-50 mg/day, atenolol day, captopril 25-100 mg/day, clonidine day, diltiazem-SR 120-360 mg/day, prazosin 4 -20 mg/day or placebo in a double-blind prospective trial. The assigne d drug was titrated to a goal BP of < 90 mm Hg. Patients not achieving goal BP were re-randomised to an alternative single active drug. Non- responders to the second drug received the first drug in combination w ith the second. Of the 102 non-responders to both drugs who qualified for the combination, 59 (57.8%) responded. The combination pairs that included a diuretic achieved diastolic goal BP in 69% and < 140 mmHg s ystolic in 77% compared with 51% and 46%, respectively, for those comb inations without a diuretic (P = 0.067; P = 0.002). Six of the eight t erminations due to adverse drug reactions were in combinations contain ing prazosin; three of these six were hypotensive reactions. We conclu de that two single drugs of insufficient efficacy to control BP indivi dually have a high probability of achieving goal BP when combined, esp ecially if the combination contains a diuretic.