Prazosin in hypertension. Part I. Clinical experience in 100 patients.

This paper reports the findings of an open evaluation of 100 patients treated with prazosin. When prazosin was added to existing hypotensive regimens in 50 patients whose blood pressure was poorly controlled, 36 (72 percent) became normotensive. Treatment was initiated with prazosin in a further 50 patients. Satisfactory control was achieved with prazosin alone in 24 and 20 of these became normotensive. The remaining 26 patients received in addition a beta-adrenoreceptor blocking agent together with a thiazide diuretic in 14. While prazosin alone caused a mean fall of 26/14mmHg in this group, the enchanced efficacy of combined therapy achieved a normal blood pressure in 19 (73 percent) and a total mean fall in pressure of 42/28mmHg. The most frequent side effect was dizziness or faintness at the start of therapy or, less often, when the dose was increased. This is minimised by using a low initial dose of 0.5mg two or three times daily. Prazosin is an effective hypotensive agent, used alone or in combination, in most patients with hypertension of all degrees of severity.