Antihypertensive effect of indapamide with special emphasis on renal prostaglandin production

A study was undertaken in 19 patients with benign to moderate essential hypertension to verify the effect of indapamide alone or combined with a beta-blocker on plasma renin activity, plasma aldosterone, serum potassium and urinary prostaglandins PGE2 and PGF2a. Blood pressure was normalized in 11 (58%) patients with 2.5 mg indapamide/day. In the remaining 8 patients, the addition of pindolol resulted in blood pressure control. Under indapamide, a 70% increase in plasma renin activity and 81% (p less than 0.01) in plasma aldosterone was observed, whereas there was an 18% (p less than 0.001) decrease in potassium. Simultaneously, an increase in urinary PGE2 and PGF2a was observed; these values were significant for PGE2 (p less than 0.025). The addition of pindolol did not produce significant change in the biochemical parameters measured. The increase in the excretion rate of primary prostaglandins could play a role in the mode of action of indapamide.