Antihypertensive effects of doxazosin in systemic hypertension and comparison with terazosin

Abstract

A multicenter, double-blind study compared the antihypertensive efficacy and safety of doxazosin and terazosin as once-daily therapy. Doxazosin, a potent antihypertensive agent, selectively inhibits α1 adrenoceptors. Its pharmacokinetic profile, including gradual onset of action, long plasma elimination half-life and long duration of action, permits once-daily dosing. Terazosin, a structural analog of prazosin, also inhibits α1 adrenoceptors and is recommended as once or twice-daily therapy. Nineteen (73%) of 26 patients randomly assigned to receive doxazosin were therapeutic successes; 17 (65%) achieved normalized blood pressure (defined as blood pressure ≤ 90 mm Hg). The mean final daily dosage in patients classified as therapeutic successes was 2.4 mg. Eighteen (64%) of 28 terazosin-treated patients were considered therapeutic successes; 16 (57%) achieved normalized blood pressure. The mean final daily dosage in patients classified as therapeutic successes was 5.6 mg. Treatment-related side effects were observed in 30% of doxazosin-treated and 39% of terazosin-treated patients. Most side effects observed in either treatment group were mild or moderate and either disappeared or were tolerated with continued therapy. Doxazosin is an effective, well-tolerated, once-daily antihypertensive agent; it is comparable with terazosin but at a lower daily dosage. © 1987.