Indomethacin and its effect on renal function and urinary kallikrein excretion in premature infants with patent ductus arteriosus.

In the course of a double-blind trial of intravenous indomethacin therapy in premature infants with patent ductus arteriosus, renal function and urinary kallikrein were studied in 21 infants following one dose of either saline placebo or indomethacin. Ten infants were assigned to the control group and 11 were in the indomethacin group. Significantly lower urine output, fraction excretion of sodium, fraction excretion of chloride, and urinary kallikrein were noted by 45%, 59%, 63%, and 51%, respectively, in the indomethacin group as compared to the control group. There was a concomitant decrease in serum sodium concentration (P less than .05) at 24 hours following indomethacin therapy. No significant difference in glomerular filtration rate was seen between the control group and the indomethacin-treated infants.