Unprescribed cannabinoids and multiple sclerosis: a multicenter, cross-sectional, epidemiological study in Lombardy, Italy.

Introduction: Cannabinoids are approved for spasticity and pain in multiple sclerosis (MS). In 2017 the prevalence of current users in the Italian general population was 10.2%, while data on Italian MS patients are limited.
Methods: From March 2022 to February 2023, we conducted a multicenter, cross-sectional study. Adult MS patients completed an anonymous online survey. The primary outcome was the estimated prevalence of unprescribed cannabis current use. Cannabis use patterns and associations with clinical and socio-demographical variables were investigated. The binomial method was used to estimate 95% confidence interval (95% CI) for primary outcome.
Results: 5620 patients were invited and 2024 (36.0%) were included (mean age 45.2 years, females 64.5%). Relapsing remitting form was the most frequent (77.3%). Median expanded disability status scale (EDSS) was 2.0. The proportion of current users was 15.5% (95% CI 13.9-17.1) and 36.4% of them disclosed to their physician their unprescribed cannabis use. 15.0% patients were former users while 69.5% never used cannabis. Current users more frequently reported a medical use (i.e., current medical users) compared to former users (p < 0.001). 41.1% of never users would use cannabis if it was legal. Young age, being male, and a free marital status were associated with current use. Current medical users had higher disability, spasticity and pain, reduced quality of life, concomitant neurological/psychiatric drugs and analgesics use. Unprescribed cannabis appeared relatively safe, with limited addiction risk, and reported clinical benefits, including concomitant medications reduction.
Conclusion: Unprescribed cannabis use is common in patients with MS in Italy, with observed prevalence seemingly superior to the general population, often intended for medical use and without the disclosure to the treating physician, although with potential clinical benefits.
Competing Interests: Declarations Conflicts of interest Dr. R. Giossi received support for congress participation from Mylan and acted as a consultant for Daiichi-Sankyo, outside this work. Prof. M. Filippi is Editor-in-Chief of the Journal of Neurology, Associate Editor of Human Brain Mapping, Neurological Sciences, and Radiology; received compensation for consulting services from Alexion, Almirall, Biogen, Horizon, Merck, Novartis, Roche, Sanofi; speaking activities from Bayer, Biogen, Celgene, Chiesi Italia SpA, Eli Lilly, Genzyme, Horizon, Janssen, Merck-Serono, Neopharmed Gentili, Novartis, Novo Nordisk, Roche, Sanofi, Takeda, and TEVA; participation in Advisory Boards for Alexion, Biogen, Bristol-Myers Squibb, Horizon, Merck, Novartis, Roche, Sanofi, Sanofi-Aventis, Sanofi-Genzyme, Takeda; scientific direction of educational events for Biogen, Merck, Roche, Celgene, Bristol-Myers Squibb, Lilly, Novartis, Sanofi-Genzyme; he receives research support from Biogen Idec, Merck-Serono, Novartis, Roche, Italian Ministry of Health, Fondazione Italiana Sclerosi Multipla, and ARiSLA (Fondazione Italiana di Ricerca per la SLA). Dr. C. Zanetta received compensation for speaking activities, and/or consulting services, from Alexion, Astrazeneca, Biogen, Bristol-Myers Squibb, Janssen, Merck, Novartis, Roche, Sanofi. Dr. C. Antozzi received funding for traveling from Teva, Merck and Biogen. Dr. L. Brambilla received honoraria for speaking from Novartis, Roche, Horizon, and for traveling from Sanofi-Genzyme, Merck-Serono, Novartis, Horizon and Roche; she acted as an Advisory Board member of Sanofi-Genzyme, Novartis and Merck-Serono and she is involved as principal investigator in clinical trials for Roche and Merck-Serono. Dr. P. Confalonieri has received honoraria for speaking or consultation fees from Novartis, Bristol Myers and Biogen, has received funding for travel to attend scientific events or speaker honoraria from Merck-Serono, Biogen Idec, Mylan and Roche. He has also received institutional research support from Merk-Serono, Novartis and Roche. He is also principal investigator in clinical trials for Novartis and Roche. Dr. S.G. Crisafulli received support for congress participation from Mylan, Merck-Serono, Novartis. He acted as an Advisory Board member for Novartis. Dr. P. Annovazzi received honoraria for lecturing and participation in advisory boards, and/or travel expenses for attending congresses and meetings from Alexion, Almirall, Biogen, BMS-Celgene, Janssen, Merck, Novartis, Roche, Sanofi-Genzyme, Teva and Viatris. Dr. C. Barrilà participated in improvements groups for Biogen, Sanofi, Novartis, and Merck. Dr. M. Ronzoni received honoraria for congress participation and/or advisory board from Alexion, Almirall, Biogen, Bristol Meyers Squibb, Horizon, Genzyme, Merck, Novartis, Roche, Sanofi, and Teva. Dr. S. Gustavsen has received support for congress participation from Merck and Sanofi. Dr. V. Torri Clerici acted as an Advisory Board member of Biogen Idec and Novartis, and received funding for travelling and honoraria for speaking or writing from Teva, Novartis, Genzyme, Almirall. She received support for research project by Almirall. Other authors have nothing to disclose.
(© 2024. The Author(s).)