Acute effects of clometacin on renal prostaglandin biosynthesis in healthy subjects.

In 6 healthy subjects the effect of clometacin on renal function, sodium and water excretion, plasma renin activity and urinary excretion of prostaglandins has been studied. After four days of treatment with clometacin, the excretion of urinary prostaglandins E2, F2 alpha and 6 keto F1 alpha and thromboxane B2 were reduced by 61.2, 41.2, 59 and 42%, respectively. 62% reduction in plasma renin activity was also observed. There was no significant change in mean blood pressure, heart rate, body weight, creatinine clearance or urinary excretion of sodium. It is concluded that clometacin is an efficient cyclooxygenase inhibitor in healthy individuals with a normal sodium intake, and that caution is required when giving clometacin to patients at risk of developing renal failure during treatment with a cyclooxygenase inhibitor.