Adverse events following cannabis for medical use in Tuscany: An analysis of the Italian Phytovigilance database

Aims: Despite a significant increase in using cannabis for medical purposes, current evidence on its safety in real-world clinical practice is still poorly characterised. By a case-by-case analysis of spontaneous reports of suspected adverse events (AEs) collected in Tuscany within the Italian Phytovigilance database, the aim of the present study was to describe AEs occurred in patients exposed to medical cannabis. Methods: We evaluated all reports of cannabis-related suspected AEs collected within the Phytovigilance database up to December 2018. Information regarding cannabis therapy, patient's demographic and clinical characteristics, concomitant medications, AE description according to the Medical Dictionary for Regulatory Activities (MedDRA) classification, AE seriousness and AE outcome, were collected. The causality assessment was performed following World Health Organisation–Uppsala Monitoring Centre criteria. Results: Fifty-three cannabis-related AE reports were analysed. The majority of patients were females (77.3%), with a mean age of 61.9 years. Thirty-nine (73.6%) cases were defined as nonserious and the majority of them (86.9%) showed a complete resolution or improvement. Forty-six (86.8%) cases were judged as probably related to cannabis consumption. The most frequently reported system organ class was psychiatric and nervous system disorders, and a potential drug–drug interaction was present in 16 cases. Conclusion: Cannabis was generally well tolerated and the majority of AEs were mild and transient. Our analysis highlighted important safety issues for clinical practice, in particular the need for an accurate prescription monitoring during the titration phase, particularly in the presence of concomitant medications.