TY - JOUR T1 - Premature closure of ductus arteriosus after a single dose of diclofenac during pregnancy JF - Drug and Therapeutics Bulletin JO - Drug Ther Bull DO - 10.1136/dtb.2022.243485rep SP - dtb-2022-243485rep AU - Constança Soares dos Santos AU - Patricia Vaz Silva AU - Rui Castelo AU - Joaquim Tiago Y1 - 2022/08/31 UR - http://dtb.bmj.com/content/early/2022/08/31/dtb.2022.243485rep.abstract N2 - In conjunction with BMJ Case Reports, DTB will feature occasional drug-related cases that are likely to be of interest to readers. These will include cases that involve recently marketed drugs for which there is limited knowledge of adverse effects and cases that highlight unusual reactions to drugs that have been marketed for several years.A male term neonate was admitted to the neonatal intensive care unit in the first hours of life with central cyanosis. Echocardiogram showed severe biventricular hypertrophy, markedly right-sided, tricuspid regurgitation, a patent foramen ovale and a closed ductus arteriosus (CDA). The mother recalled being treated with a single dose of intravenous diclofenac for low back pain 2 weeks earlier. The newborn was started on propranolol with symptomatic improvement and was discharged on day 10. At 1-month follow-up, he showed complete resolution of ventricular hypertrophy and suspended propranolol. In the literature, of the 22 cases of CDA after intrauterine exposure to diclofenac, 11 resolved in utero, 3 required ventilatory and inotropic support and 1 evolved to persistent pulmonary hypertension. In this case, a thorough anamnesis was key to identify the probable cause of an otherwise unexplained transient ventricular hypertrophy. This case also alerts to the fetal risks of non-steroidal anti-inflammatory drugs during the third trimester, requiring close monitoring.During pregnancy, the ductus arteriosus (DA) is critical for normal fetal circulation. It communicates the pulmonary artery to the aortic arch, allowing a right-to-left shunt, in which the oxygenated blood that reaches the right atrium from the placenta bypasses the highly resistant pulmonary circulation.1 The patency of the DA in utero is maintained by relative fetal hypoxia, by locally produced and circulating prostanoids (mainly Prostaglandin E1 (PGE1) and Prostaglandin E2 (PGE2), respectively) and by endothelial nitric oxide. As of the third trimester, DA becomes progressively more sensitive to … ER -