Minimal effective dose of indomethacin for the treatment of patent ductus arteriosus in preterm infants.

The aim of this study was to determine if it was possible to decrease the number of boluses of indomethacin for the treatment of patent ductus arteriosus. This retrospective study included 46 preterm neonates (<34 weeks' GA) who had had an ultrasound diagnosis predictive of subsequent symptomatic patent ductus arteriosus. All patients had received a daily intravenous doses of indomethacin, 0.1 mg/kg. Mean age at initiation of treatment was 4.5 +/- 3.1 days. Patency of the ductus arteriosus was controlled echocardiographically each day and treatment was discontinued as soon as the ductus arteriosus was closed. The initial success rate was 84.7%, of which 6.5% reopened. The mean cumulative dose of indomethacin was 0.35 mg/kg. There was no correlation between gestational age or birth weight and total cumulative dose. Overall tolerance was satisfactory with only one case of transient acute renal failure. A weak correlation between the cumulative dose of indomethacin and natremia (r = -0.43) or weight gain (r = 0.35) was noted, and none with serum creatinine or blood urea nitrogen levels. We confirm that lower indomethacin treatment of patent ductus arteriosus in premature neonates are as effective as standard protocols.