Pharmacological Closure of Patent Ductus Arteriosus in Extreme Low Birth Weight Infants: A Comparison of the Efficacy and Side Effects between Indomehtacin and Ibuprofen Chung-Ming Chen, MD, PhD, a,b,c Adrian Florens, MD, d Shou-Yin Wu, MD, d Ho-Shun Ko, MD, e Yung-Ting Ko, MD, e,b,c Hsi Chang, MD, PhD, a,b,c Ju-Chien Cheng, PhD, f and Tsu Fuh Yeh, MD, PhD c,e a Dept of Ped, Taipei Medical University Hospital; b Dept of Ped, College of Medicine, Taipei Medical University; c Maternal and Child Health Research Center, Taipei Medical University, Taipei, Taiwan; d Division of neonatology, John Stroger’s Hospital of Cook County, Chicago, USA; e Dept of Ped, Taipei Medical University-Shuang Ho Hospital; f Dept of Biotechnology, China Medical University, Taichung, Taiwan. Results Abstract Background: ELBW infant has immature kidney and often has poor response to PG inhibitors and has high mortality and morbidity. There are very few studies being done specifically on ELBW infant. Objective: To compare the efficacy of ductus closure, side effects, urinary exertion of PG and mortality and morbidity between indomethacin (Ind.) and ibuprofen (Ibu.) in ELBW infant. Design/Methods: 110 ELBW infants with hemodynamically sig. PDA were randomized into 2 groups: 56 received Ind. (0.2, 0.1 and 0.1 mg/kg, q24h) and 54 received Ibu. (10, 5 and 5 mg/kg, q24h). Urine and time-matched serum Na, Cl, K, Cr, estimated GFR (CCr), FENa, FEK, Cosm and CH2O were calculated. Urinary PGE was measured by RIA. Results: The two groups were comparable in BW, gestational age and prenatal steroid (802±156 vs. 798±161 gm, 26.2±1.8 vs. 26.2±1.4 wk, 75% vs. 74%) and in pulmonary status and size of ductus (0.19±0.46 vs. 0.17±0.07 mm) on admission to study. Infants in Ind. group had a sign. lower U/O (54±16 vs. 67±24 ml/kg/d, p<0.05), lower GFR (8.9±2.1 vs. 17.8±10.4 ml/min/1.73 m2, p<0.01), higher serum Cr (1.25±0.36 vs. 0.93±0.43 mg/dl, p<0.01) on d-1. Infants in Ind. group also had a sign. lower urinary PGE on d-1 (210±144 vs. 295±220 pg/mg Cr, p<0.05) indicating a more renal PG inhibition. Infants in Ind. group had a sign. higher FENa on days 1, 2, 5 and 7 than those of infants in the Ibu. group. Table shows the efficacy, mortality and morbidity of treatment in Ind. and Ibu. Groups. Results Conclusions Fig. 1. The changes of the respiratory status and the number of infants on IMV, CPAP, and the number of infant died during the study. Fig. 2. Urinary PGE2 excretion during the study (*P <.05). In ELBW infant, Ibu. has comparable efficacy of ductus closure as Ind. has less renal adverse effects. The role of PG on renal tubular function remains to be further studied. Introduction Pharmacological closure of ductus arteriosus with prostaglandin (PG) inhibitors has been used for years. Previous studies indicated that ibuprofen has similar effect on ductal closure as indomethacin but has less adverse effects on renal function, cerebral blood flow and mesenteric blood flow. There are, however, very few studies being done specifically on extremely low birth weight (ELBW) infant < 1000 g. This group of infants has immature kidney and often has poor response to PG inhibitors and has high mortality and morbidity.