A multiclinic double-blind comparison of timolol and hydrochlorothiazide alone and in combination in th e treatment of essential hypertension.

In a multicenter randomized double-blind trial, we compared the antihypertensive effects of 12 weeks of therapy using timolol maleate, a new beta-adrenergic blocking agent, alone and in combination with hydrochlorothiazide, and hydrochlorothiazide alone in 70 outpatients with mild to moderate uncomplicated essential hypertension (61 of whom completed the study). All three groups showed significant blood pressure reductions in both supine and standing positions which were most marked in the timolol-hydrochlorothiazide group (154/103 leads to 129/85 mm Hg). A good or excellent therapeutic response was obtained in 20 of 21 patients in the timolol-hydrochlorothiazide group. In 16 of 20 patients receiving timolol alone, and in 10 of 20 receiving hydrochlorothiazide alone. Adverse reactions were minimal in all treatment groups but highest in the hydrochlorothiazide group. It was concluded that timolol-hydrochlorothiazide combination is more effective than either drug alone for management of hypertension and that timolol alone or with hydrochlorothiazide is well tolerated.