Comparative effectiveness of drugs used to constrict the patent ductus arteriosus: a secondary analysis of the PDA-TOLERATE trial (NCT01958320)

OBJECTIVE: To evaluate the effectiveness of drugs used to constrict patent ductus arteriosus (PDA) in newborns <28 weeks. METHODS: We performed a secondary analysis of the multi-center PDA-TOLERATE trial (NCT01958320). Infants with moderate-to-large PDAs were randomized 1:1 at 8.1±2.1 days to either Drug treatment (n=104) or Conservative management (n=98). Drug treatments were assigned by center rather than within center (acetaminophen: 5 centers, 27 infants; ibuprofen: 7 centers, 38 infants; indomethacin: 7 centers, 39 infants). RESULTS: Indomethacin produced the greatest constriction (compared with spontaneous constriction during Conservative management): RR (95% CI) = 3.21 (2.05-5.01)), followed by ibuprofen=2.03 (1.05-3.91), and acetaminophen=1.33 (0.55-3.24). The initial rate of acetaminophen-induced constriction was 27%. Infants with persistent moderate-to-large PDA after acetaminophen were treated with indomethacin. The final rate of constriction after acetaminophen±indomethacin was 60% (similar to the rate in infants receiving indomethacin-alone (62%)). CONCLUSION: Indomethacin was more effective than acetaminophen in producing ductus constriction.