High rates of off-label use in antibiotic prescriptions in a context of dramatic resistance increase: a prospective study in a tertiary hospital

The use of antibiotics, as any other drug, is regulated by the terms of its marketing authorisation, notified in the Summary of Product Characteristics (SPC). If a prescription is not in accordance with the SPC, the physician prescribes off-label. There is very little literature regarding off-label use of antibiotics in adult healthcare facilities. A prospective monocentric study was conducted during 11 days from February to June 2015 in hospitalised patients from a tertiary teaching hospital with a high prevalence of multidrug-resistant organism colonisation to evaluate off-label use of antibiotics. Two independent experts assessed whether prescriptions complied with the latest guidelines in infectious diseases and whether off-label use of antibiotics was associated with an increased risk of adverse events. In total, 160 antibiotic prescriptions were analysed, of which 76 (47.5%) were off-label. Of the 76 off-label prescriptions, 50 (65.8%) were off-label regarding indications and 26 (34.2%) regarding doses. Nevertheless, 46/50 off-label indications (92.0%) and only 14/26 off-label doses (53.8%) were approved by experts, especially because of dose adjustment requirements. During follow-up, the rate of reported adverse events was not statistically different between patients with (n = 76) and without (n = 84) off-label prescriptions (P = 0.35). In a context of multidrug resistance and a lack of new drugs, high rates (47.5%) of antibiotic off-label use were observed in our hospital, but without an increased rate of adverse events. Moreover, 78.9% of off-label uses were in accordance with guidelines. Therefore, the SPC is not the warrant of an appropriate use of antibiotics. (C) 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.