Medical Cannabis Use in France: An Observational Safety Study Based on the RECANN Registry and the Pharmacovigilance/Addictovigilance System From 2021 to 2024

INTRODUCTION: The French National Agency for Medicines and Health Products Safety implemented in 2021 a nationwide experimentation for medical cannabis (MC), designed to assess the feasibility of implementing a new public health policy. A dedicated registry was established to support the notification of adverse drug reactions (ADRs). The objective of this study was to describe the safety data collected during the first 3 years of experimentation. METHOD: Data related to MC use were extracted from the registry and the French pharmacovigilance and addictovigilance database between March 26, 2021, and March 31, 2024. RESULT: Among the 3164 included patients, at least one ADR was reported in 1186 patients, including 81 patients (3%) with serious ADRs (SADRs). The most common ADRs were neurological (37.2%), gastrointestinal (16.9%), and psychiatric (15.2%). Among SADRs, six cases of acute coronary syndromes were reported, along with eight cases of suicidal thoughts including one suicide attempt. Half of these psychiatric events occurred in patients without a prior psychiatric history, and no cases of psychosis were documented. Regarding addictovigilance, only 12 ADRs were analyzed: seven withdrawal syndromes, three cases of tolerance, and two cases of THC-containing inflorescence misuse, including one case of MC use disorder. DISCUSSION: During the experimentation, 3% of patients treated with MC experienced at least one serious ADR. The safety profile was dominated by neurological, gastrointestinal, and psychiatric ADRs. Only one case of MC misuse was identified with inflorescences. This study is observational and non-comparative and cannot provide a comprehensive assessment of the risk associated with MC use.