Renal effects and urinary excretion of prostaglandin following indomethacin therapy in premature infants with patent ductus arteriosus.

Renal side effects and urinary prostaglandin were evaluated in 10 premature infants (Mean +/- SD: BW 1245 +/- 290 gm, GA 32 +/- 2.2 wks, Postnatal age 7.7 +/- 3.8 days) with significant PDA who were given one dose of indomethacin (0.3 mg/kg intravenously). There was a significant decrease in urinary output, osmolal and free water clearance after therapy. The fractional excretion of sodium, chloride, potassium, glomerular filtration rate and urinary prostaglandin E2 also decreased but were not statistically different from the baseline values. In infants who responded to indomethacin with ductus closure, their renal functions appeared to be preserved even though they had higher plasma indomethacin levels than the non-responders in whom significant changes in renal function were observed following indomethacin therapy. This observation suggested that the improved renal hemodynamics following the closure of the ductus may minimize or attenuate the renal side effects of indomethacin.