INDOMETHACIN AND RENAL FUNCTION: THE EFFECTS OF ADDITION OF LOW-DOSE DOPAMINE

Abstract

The renal function changes induced by indomethacin during treatment of patent ductus arteriosus often preclude its use. To determine if concommitent low-dose dopamine improved renal function, we studied renal parameters in Beagle puppies. The animals were sedated; tracheostomy was performed and mechanical ventilation begun. The femoral artery and vein were catheterized and the right ureter isolated and catheterized for urine collection. Four groups were studied: controls, indomethacin treated, dopamine treated, and indomethacin and dopamine treated. Each animal was allowed to serve as its own control at time 0-120 min. At time 120 the treated animals received .2 mg/kg indomethacin intravenously and/or 4 mcg/kg/min dopamine by continuous intravenous infusion. Time 120-240 served as the next collection period. All animals received constant fluid intake. Blood pressure, heart rate and blood gases remained stable. Glomerular filtration rate (GFR), sodium para-aminohippurate (PAH) clearance, fractional sodium (Na) excretion, osmolar and free H2O clearance were obtained. GFR was significantly decreased (p<.05) in animals that received indomethacin alone, and unchanged in the groups receiving dopamine, dopamine and indomethacin and controls. There was a trend (p<.1) indicating fractional Na excretion decreased only in the group receiving indomethacin. This data suggests that low-dose dopamine may improve renal parameters when used with indomethacin.