The renal hemodynamic effects of ibuprofen in the newborn rabbit

In early childhood, nonsteroidal anti-inflammatory drugs are mainly used to either prevent or treat premature labor of the mother and patent ductus ar teriosus of the newborn infant. The most frequently used prostaglandin-synt hesis inhibitor is indomethacin. Fetuses exposed to indomethacin in utero h ave been born with renal developmental defects, and in both the unborn chil d and the term and premature newborn this drug may compromise renal glomeru lar function. The latter has in the past also been observed when i.v. indom ethacin or i.v. acetylsalicylic acid (aspirin) were administered to newborn rabbits. The present experiments were designed to evaluate whether ibuprof en has less renal side effects than indomethacin, as claimed. Three groups of anesthetized, ventilated, normoxemic neonatal rabbits were infused with increasing doses of ibuprofen (0.02, 0.2, 2.0 mg/kg body weight) and the fo llowing renal parameters were measured: urine volume, urinary sodium excret ion, GFR, and renal plasma how. Renal blood flow, filtration fraction, and the renal vascular resistance were calculated according to standard formula e. Intravenous ibuprofen caused a dose-dependent, significant reduction in urine volume, GFR, and renal blood flow with a fall in filtration fraction in the animals receiving the highest dose of ibuprofen (2 mg/kg body weight ). There was a very steep rise in renal vascular resistance. Urinary sodium excretion decreased. These experiments in neonatal rabbits clearly show th at acute i.v. doses of ibuprofen also have significant renal hemodynamic an d functional side effects, not less than seen previously with indomethacin.