An open trial of prazosin in the treatment of hypertension.

An open trial of prazosin has been conducted among 18 males aged 18-68 years (mean 42.7) and 22 females aged 23-70 years (mean 47.5) seen at the Lagos University Teaching Hospital Hypertension Clinic. 3 suffered from mild to moderate hypertension and 9 suffered from severe hypertension. The dose employed ranged from 2 to 60 mg per day in 2 or 3 divided doses. All 6 patients whose placebo diastolic pressure was below 100 mm Hg gave excellent response. 19(76%) of the 25 patients whose placebo diastolic pressure ranged from 100 to 114 mm Hg gave excellent response. Only 3 to 9 patients whose placebo diastolic pressure ranged from 115 to 129 mm Hg gave excellent response. There was improved response when polythiazide 2 mg daily was added to the treatment. The total number giving excellent response increased from 28 (70%) to 36 (90%). In 3 cases (7.5%), the response was fair and one case (2.5%) remained poor. In most cases there was slight increase in pulse rate. The side effects encountered included palpitation in 8 patients 3 of whom also had postural hypotension. There were no biochemical or haematological abnormalities caused by prazosin but on continued therapy 16 patients developed tolerance to its effect. Thus prazusin has been found to be useful addition to the antihypertensive arm amentarium.