Prazosin and clonidine for moderately severe hypertension

Abstract

In a single-blind comparative study of the cases of 30 moderately hypertensive patients, clonidine hydrochloride and prazosin hydrochloride had similar effectiveness in lowering blood pressure. Neither agent had significant effects on the renin-aldosterone axis. Addition of polythiazide to prazosin and chlorthalidone to clonidine notably increased the antihypertensive effect of both drugs. Serum cholesterol levels were observed to decrease when added to the regimen. The patients treated with clonidine were troubled by side effects, particularly drowsiness and dry mouth. Prazosin was better tolerated, with side effects tending to diminish with time. The 1st-dose effect was seen in 2 patients given prazosin, but it did not limit treatment. Both diuretics induced notable hypokalemia.