Guimaraes AFM, et al. - In this retrospective study, researchers examined preterm newborns with patent ductus arteriosus to determine the impacts of acetaminophen in low doses as an alternative in these subjects. The patients who were treated with oral acetaminophen because treatment with indomethacin had failed or is contraindicated, were included in this study. A first dose of 25 mg/kg and maintenance doses of 30 mg/kg/day were administered for 3 to 7 days. In cases of reopening of the ductus arteriosus, a second cycle was given. After one or two cycles, 74.7% was reported as the ductus closure rate. A progressive decline in the recommendations for surgical closure was evident from 50% in the 1 st year to 6.2% in the past year. In patients in whom treatment with indomethacin or ibuprofen failed or was contraindicated, acetaminophen in low doses was proved effective as an alternative for the closure of the ductus arteriosus for preterm newborns.