The investigators propose that paracetamol will be similarly effective to ibuprofen in treating PDA in the premature neonate, with fewer side effects.

Preterm neonates with a hemodynamically significant PDA will potentially be candidates for study. After obtaining parental consent, the infants will be prospectively and randomly assigned to one of two groups: 1.po Paracetamol at a dose of 15 mg/kg every 6 hours at x 3 days or Group 2- IV indomethacin - 0.2 mg/kg/dose q 12h for three doses; or IV Ibuprofen 10 mg/kg infused over 15 minutes, followed by two doses of 5mg/kg each at 24 hour intervals (total of 3 doses).Clinical staff will be blinded as to the study group assignment of the babies and since the group 1 drug is to be given every six hours, all babies will receive a parenteral substance every 6 hours. For Group 2 infants, the intermittent doses will be IV D5W alternating with drug.All infants will fed trophic feeds (20 cc/kg/day) during the treatment for ductal closure.

Inclusion Criteria:

• Echocardiographic diagnosis of hemodynamically significant patent ductus arteriosus

Exclusion Criteria:

• Major congenital anomalies
• Life-threatening infection
• Active NEC and/or intestinal perforation
• Recent (within the previous 24 hours) intraventricular hemorrhage Grade 3-4
• Urine output <1 ml per kilogram per hour during the preceding 8 hours
• Serum creatinine concentration of >1.6 mg %
• Platelet count of <60,000 per cc.