Effects of ibuprofen and indomethacin on urinary antidiuretic hormone excretion in preterm infants treated for patent ductus arteriosus.

Objective: To compare the effects of intravenous ibuprofen and indomethacin for treatment of patent ductus arteriosus ( PDA) on urinary antidiuretic hormone ( ADH) excretion, as a cause of oliguria. Study Design: Forty-four respiratory distress syndrome prematures ( <= 34 weeks' gestation) with PDA received either ibuprofen ( n = 22) in an initial dose of 10 mg/kg followed by two doses of 5 mg/kg each after 24 and 48 h or three doses at 12-hour intervals of indomethacin ( n = 24), 0.2 mg/kg, both infused continuously over a period of 15 min. Urinary ADH excretion, diuresis, serum creatinine, urinary sodium, fractional excretion of sodium, and urinary osmolality were measured before and after treatment. Results: Indomethacin treatment caused a significant decrease in urinary ADH excretion ( 21.8 +/- 20.8 vs. 13.8 +/- 12.9 pg/ml; p < 0.05), along with a significant reduction in urinary sodium ( 92.1 +/- 36.1 vs. 64.8 +/- 35.6; p < 0.05), fractional excretion of sodium ( 68.5 +/- 37.1 vs. 45.6 +/- 37.1; p < 0.05), and urinary osmolality ( 276.2 +/- 103.9 vs. 226.4 +/- 60.3; p < 0.05). Ibuprofen treatment did not modify urinary ADH excretion and caused a statistically insignificant decrease in urinary sodium and in fractional excretion of sodium. Conclusions: Compared with ibuprofen, indomethacin caused a significant reduction in urinary ADH excretion and a significant decrease in urinary sodium and osmolality. Copyright (c) 2005 S. Karger AG, Basel.