Enalapril and hydrochlorothiazide as antihypertensive agents in the elderly

Abstract

This randomized, double blind study compared the antihypertensive effects of enalapril to hydrochlorothiazide (HCTZ) in the elderly. One hundred seventy-four patients with diastolic blood pressures (DBP) of 90-120 mm Hg or isolated systolic hypertension (ISH) (systolic BP greater than 160 mm Hg and diastolic BP less than 90 mm Hg) were studied. After four weeks of placebo, patients received either enalapril 10 mg or HCTZ 12.5 mg once daily. If the BP was uncontrolled (DBP greater than 85 mm Hg or SBP greater than 140 mm Hg) after 4 weeks, the dose was doubled. At 8 weeks, if necessary, the other drug could be added at the lower dose, then doubled 4 weeks later. Two-thirds of the patients had essential hypertension (EH), the rest ISH; 68% were male and 80% Caucasian. The baseline BPs were 167/94 mm Hg in both groups, at 8 weeks the mean BPs were 148/85 mm Hg in both groups (p less than or equal to 0.01), and at the end of the study the BPs with enalapril were 144/83 mm Hg and with HCTZ they were 145/83 mm Hg (p less than or equal to 0.01). The Caucasians showed greater BP falls on enalapril than HCTZ after 4 weeks (p less than or equal to 0.05). The SBP falls for the ISH (-22 mm Hg) and EH (-23 mm Hg) groups were similar at the end of the study. Both drugs were generally well tolerated. Laboratory adverse experiences (AEs) were 9% more common in the HCTZ patients (n.s.). Enalapril and HCTZ both seem to be effective antihypertensive agents in the elderly.