Background: From the time Sativex (THC:CBD) oromucosal spray first became available in European Union countries in 2010 for the management of treatment-resistant multiple sclerosis (MS) spasticity, data from daily practice have been collected through various projects. Methods: A retrospective registry study and a prospective safety study of THC:CBD oromucosal spray are reported. Results: The most recent analysis of a retrospective registry established in the United Kingdom (UK), Germany and Switzerland, which collected safety data on more than 900 patients, has indicated a positive risk-benefit profile for THC:CBD oromucosal spray during long-term use. Long-term continuation rates were 68% (mean follow-up time 1 year) and the mean dose was 5.4 sprays/day. No new safety concerns were identified, and adverse events of special interest for a cannabis-based medicine were limited. The UK registry has since been closed but remains open in Germany and Switzerland. A prospective safety study undertaken in Spain involved 207 patients from 13 specialized MS centres who had been prescribed THC:CBD oromucosal spray. The findings aligned closely with the UK/German/Swiss registry data in terms of 1-year continuation rates (64.7%), mean daily dose (6.6 sprays/day) and safety profile, including no evidence of addiction, abuse or misuse. Conclusions: The homogeneity between these observational studies supports the interest in THC:CBD oromucosal spray for management of MS spasticity in daily practice.
