Effects of ibuprofen and indomethacin on the regional circulation in newborn piglets

We investigated the effects of clinically comparable doses of ibuprofen and indomethacin on renal, gastrointestinal and cerebral perfusion in newborn piglets, and hypothesized that ibuprofen would have less effect on regional circulation. Animals were randomly assigned to receive ibuprofen (20 mg/kg , n = 8), indomethacin (0.3 mg/kg, n = 7) or vehicle (n = 6). Fluorescent m icrospheres were injected prior to and at 20, 40, 60, 90 and 120 min after drug administration. Regional blood flow was measured and vascular resistan ces were calculated. Cardiovascular and respiratory variables were not sign ificantly affected by either study drug or vehicle. Ibuprofen increased ren al cortical and medullary resistance by 44 and 52% (p < 0.05). However, ibu profen had no significant effects on gastrointestinal or cerebral resistanc e. Indomethacin raised renal cortical and medullary resistance by 66 and 71 % at 60 min postinjection, respectively (p < 0.05). Indomethacin increased duodenojejunal, ileal and colon resistance by 97, 102 and 75% at 60 min, re spectively (p < 0.05). Indomethacin increased cerebral cortical and cerebel lar resistance by 92 and 86% at 90 min (p < 0.05). While indomethacin and, to a lesser extent, ibuprofen both increase renal vascular resistance, indo methacin vasoconstricts the gastrointestinal and cerebral circulations whic h are unaffected by ibuprofen.