RESUMEN
ABSTRACT This study was designed to investigate the use of off-label and unlicensed drugs in a Neonatal Care Unit (NCU) and to compare the frequency of use of off-label drugs according to the drug regulatory agencies in Brazil (Agência Nacional de Vigilância Sanitária-ANVISA) and the United States Food and Drug Administration (FDA). A prospective observational study was carried out in the NCU. Prescriptions were classified as off-label and unlicensed using both ANVISA and FDA criteria. A total of 157 newborns and 1187 prescriptions were analyzed. The most prescribed drug was fentanyl (9.3%), followed by multivitamin (8.4%) and gentamicin (7.9%). According to ANVISA criteria, there were 665 (56.0%) off-label prescriptions and 86 (7.2%) unlicensed prescriptions and 95.5% of newborns received at least one drug off-label. By contrast, according to FDA criteria, there were 592 (49.9%) off-label prescriptions and 84 (7.1%) unlicensed prescriptions, and 72.0% of newborns received at least one drug off-label. The off-label use of drugs registered by ANVISA differed significantly from that of drugs registered by the FDA. There was a high frequency of off-label and unlicensed drug use in the investigated NCU, and there was an inverse relationship between off-label and unlicensed usage and the gestational age of the newborns.