The effect of indomethacin on renal function in man

Twenty-one patients with rheumatoid arthritis were given indomethacin 25 mg t.i.d. by mouth for 3 weeks followed by indomethacin 25 mg t.i.d. plus a 100 mg suppository at night, after a 5-day period on placebo capsules. The mean (+/- S.E.) 24-hour creatinine clearance was 57.8 +/- 5.7 ml/min in the placebo period and was not significantly altered during indomethacin therapy, 53.1 +/- 5.5 ml/min in the oral period and 56.6 +/- 6.4 ml/min in the oral plus suppository period (P greater than 0.1). In 6 volunteers, duplicate 2-hour creatinine clearances were performed after a single oral dose of 50 mg indomethacin. After placebo capsules the mean creatinine clearance was 133.7 +/- 9.5 ml/min and after 50 mg indomethacin it was 126.5 +/- 8.9 ml/min (P greater than 0.1). In 4 of the volunteers the mean creatinine clearance after 8 days on indomethacin 25 mg q.i.d. was 117.1+/- 5.3 ml/min (P greater than 0.1). Indomethacin plasma concentrations were in the usual range for the dose given. Indomethacin caused no reduction in the creatinine clearance in spite of causing significant inhibition of prostaglandin E synthesis.