Hydrochlorothiazide and Verapamil in the Treatment of Hypertension

Summary: The efficacy and tolerability of hydrochlorothiazide, sustained-release verapamil, and their combination was compared in patients with mild to moderate hypertension. The desing was a multicenter, randomized, double-blind clinical trial with a single-blind placebo basecline period of 2 weeks. There hundred sixty-nine patients with a diastolic blood pressure of 95–120 mm Hg were included. Treatment consisted of 12.5 mg of hydrochlorthiazide once daily. then 25 mg once daily, and finally 25 mg twice daily: the other group received verapamil at a dose of 120 mg once daily, then 240 mg once daily, and finally 240 mg twice daily. Patients not achieving target blood pressure (<90 mm Hg diastolic) were given the combination of hydrochlorothiazide and verapamil, that is 25 and 240 mg once daily and twice daily, During all time points during the study patients receiving verapamil achieved target blood pressure more often than patients receiving hydrochlorothiazide (after 8 weeks 57.7 and 42.7%. after 24 weeks, 46.8 and 26.4%: and after 48 weeks, 44.8 and 24.7%.respectively). Adding verapamil to hydrochlorothiazide was more effective in lowering blood pressure than adding hydrochlorothiazide to verapamil. the number of treatment withdrawals was essentially the same with the two drugs. Therefore. in the doses currently used in antihypertensive treatment. verapamil was more effective than hydrochlorothiazide as a single agent and in combination in mild to moderate hypertension.