Comparison of antihypertensive and hormonal effects of captopril and propranolol at rest and during exercise

Captopril and propranolol were given alone and in combination to 13 hypertensive men and the effects studied at rest (seated, supine and standing) and during exercise. The two drugs were equipotent at rest, and individual patients showed similar blood pressure responses to the two drugs. Both produced slight reduction of urinary aldosterone; when given in combination, both blood pressure and aldosterone were further reduced. During exercise the increase in blood pressure was unaffected by captopril but reduced by propranolol, and there was no correlation between individual responses to the two drugs. It is concluded that the similar effects of the two drugs on resting blood pressure are consistent with their effects on the renin-angiotensin system.