Prazosin in the treatment of patients with hypertension and renal functional impairment.

Prazosin was used as an additional antihypertensive agent for treating 16 patients with hypertension and significant renal functional impairment. The drug was effective in 13 patients at a mean daily dose of 7.9 mg. The most important side effect of prazosin treatment was dizziness which occurred on standing or following exertion, and was seen either after the first dose or following a large increase in dose. This could be prevented by giving the very first dose of 0.5 mg late in the evening. Five patients complained of palpitations. In no patient was there a deterioration in renal function which could be attributed to prazosin. Five women had a significant improvement in renal function.