Off-label use of psychotropic drugs in a Swiss paediatric service: similar results from two different cohort studies

The high off-label use of drugs in paediatric patients raises questions on the efficacy and safety when prescribing psychotropic drugs. In our studies, we aimed to characterise the use of psychotropic drugs in the paediatric service of a tertiary hospital and quantify the proportion of off-label prescriptions with respect to age, indication and dosage recommendations approved in Switzerland, France and the USA. We conducted a retrospective cohort study (RCS) that included hospitalised patients from 1 December 2017, to 28 June 2018 with at least one PD prescription (n = 74) and a prospective cohort study (PCS) that included those hospitalised from 29 June 2018, to 30 November 2018 with at least one psychotropic drug prescription (n = 37). For both studies, we collected demographic, medical and medication data. Off-label prescriptions were identified by comparing the marketing authorisations published in the three selected countries. The average age of RCS and PCS patients were 13 ± 3 years and 14 ± 2 years, respectively. Of the 168 and 86 psychotropic prescriptions collected in the RCS and PCS, respectively, 70% and 71% prescriptions were off-label based on Swiss marketing authorisations. These rates declined when compared with French marketing authorisations (61% and 67% prescriptions) and were significantly lower when compared with American marketing authorisations (56% and 51% prescriptions). Psychotropic drugs were often prescribed as needed in both studies (53% and 43% of prescriptions), with only half of the patients actually receiving one of these prescribed psychotropic drugs. Our results showed a high proportion of off-label prescriptions of psychotropic drugs in a hospital setting. The off-label prescription rates according to Swiss marketing authorisations were the highest when compared with French and American marketing authorisations. Harmonisation of either international marketing authorisations or dosage recommendations at a national level could be a step forward to improved and evidence-based use of psychotropic drugs in children and adolescents.