Off-label use of drugs and adverse drug reactions in pediatric units: A prospective, multicenter study

Background: Given the growing use of off-label in pediatric practice, there is a growing interest on pharmacovigilance programs monitoring the occurrence of adverse drug reactions related to off-label drug prescription in childhood. Patients and Methods: The results of a one-year program of pharmacovigilance issued in the Sicilian Region, Italy, are herein presented. The study involved 6 pediatric and neonatal centres and prospectively reviewed the prescriptions of 5,060 patients, who were stratified for age (newborn, infant, children, adolescents). Results: A total of 14,916 prescriptions were issued for 5,060 patients. Among them, 454 patients [8.97%] received at least one off-label drug. Among the off-label treated patients, 255 [56.2%] were newborns. Anti-infective drugs were the most frequent off-label used drugs, followed by drugs for alimentary tract and metabolism and drugs for blood or blood forming organs. Ninety adverse drug reactions were recorded [1.78% of the total patients]. They occurred after an off-label prescription in 33 out of 90 [36.7%], while those occurring after an on-label prescription were 57 [63.3%]. Patients treated with an off-label drug had a significantly higher risk of adverse drug reactions [7.3% vs. 1.2%; p <0.01]. Conclusion: The present study indicates that children admitted to neonatal intensive care units are likely to receive an off-label medication; children who receive an off-label medication are usually more likely to be treated with more medication than the others; adverse drug reactions occur in patients admitted in neonatal intensive care and pediatrics are units are more frequently with off-label than with on-label drugs.