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.1-7 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. We hypothesized that, in ELBW infants, the ductal and renal response to PG inhibitors may be different between indomethacin and ibuprofen.

The aims of this study are to compare the efficacy, the side effects and the renal prostaglandin (PG) excretion between indomethacin and ibuprofen in extremely low birth weight (ELBW) infants. We enrolled one hundred and ten ELBW infants who had clinically significant and echo-evidence patent ductus arteriosus were assigned into 2 groups, 56 received indomethacin (0.2 mg/kg, 0.1 mg/kg and 0.1 mg/kg in 24 hours interval) and 54 received ibuprofen (10 mg/kg, 5mg/kg and 5 mg/kg in 24 hours interval). Serum electrolytes, creatinine, renal function (urine output, glomerular filtration rate (GFR), fractional excretion of sodium and potassium, osmolar clearance and free water clearance), urinary PG excretion, pulmonary outcome and mortality were all evaluated.

Inclusion Criteria:

• The selection criteria were: (1) preterm infants with birth weight <1000 g; 2) radiographic diagnosis of respiratory distress syndrome (RDS); (3) requirement of mechanical ventilation and (4) echocardiographic and clinical evidence of significant patent ductus arteriosus (PDA).

Exclusion Criteria:

• Exclusion criteria included: (1) evidence of infection or sepsis; 2) lethal congenital anomalies; (3) oliguria (< 1 ml/kg/h) and/or serum creatinine > 2.0 mg/dl and (4) low platelet count (< 50,000/mm3) or bleeding tendency.