Reduction of the antihypertensive effect of captopril induced by prostaglandin synthetase inhibition.

The effects of prostaglandin synthetase inhibition by indomethacin on blood pressure and hormonal variations induced by captopril were studied in eight patients with essential hypertension and in six nonhypertensive subjects. Captopril antihypertensive effect and captopril-induced plasma renin increase were almost totally abolished by a short-term administration of indomethacin (50 mg t.i.d.). These results support the hypothesis that prostaglandins contribute to the antihypertensive effects of ACE inhibitors. It may be of clinical importance that anti-inflammatory drugs that inhibit PG-synthetase can also blunt the antihypertensive action of ACE inhibitors.