EFFICACY AND SAFETY OF HYDROCHLOROTHIAZIDE VERSUS A COMBINATION OF BENAZEPRIL AND HYDROCHLOROTHIAZIDE

In a 14-week, multicenter, double-blind study, 152 patients with essen tial arterial hypertension (mean age, 57 years; 53% women) were random ly assigned to a new fixed combination of the angiotensin-converting e nzyme inhibitor benazepril 5 mg plus hydrochlorothiazide 6.25 mg (FC) or to hydrochlorothiazide 25 mg (HCTZ) monotherapy. The daily dose of either treatment was titrated in a double-blind format based on indivi dual blood pressure response. All biochemical examinations were perfor med in a central laboratory. At the end of week 4, normalization of bl ood pressure (supine diastolic blood pressure less-than-or-equal-to 90 mm Hg) was achieved in 53% of patients treated with FC compared with 15% of patients treated with HCTZ; at the end of week 8, 84% of patien ts treated with FC achieved normalization compared with 77% of patient s treated with HCTZ. Mean serum potassium values decreased from 4.45 m Eq/L (baseline) to 4.16 mEq/L (week 4) to 4.06 mEq/L (week 8) with HCT Z, and varied from 4.34 mEq/L (baseline) to 4.40 mEq/L (week 4) to 1.3 7 mEq/L (week 8) with FC, a highly significant difference between trea tment groups (P < 0.001). At the end of week 8, serum potassium levels differed between the two groups by 0.31 mEq/L (95% confidence interva ls = 0.21 to 0.49 mEq/L, P = 0.0001). Individual values of serum potas sium below 3.0 mEq/L occurred with HCTZ treatment but not with FC. Adv erse effects were rare, mild, and equally distributed between treatmen t groups. We conclude that in patients with mild-to-moderate essential hypertension, FC and HCTZ cause blood pressure to fail comparably; ho wever, treatment with FC carries no risk of hypokalemia, most likely d ue to the very low dose of diuretic required for antihypertensive acti on and the associated potassium-sparing effect of benazepril.