Abstract

Observational Safety Study of THC:CBD Oromucosal Spray (Sativex) in Multiple Sclerosis Patients with Spasticity

Celia Oreja-Guevara, Bonaventura Casanova, Carlos Manuel Ordás, Carlos Vila Silván, David Asensio and Mariona Massana

Abstract Background: Subsequent to introduction in June 2010 in the United Kingdom and Spain of tetrahydrocannabinol (THC) : cannabidiol (CBD) oromucosal spray (Sativex®) for management of multiple sclerosis (MS) spasticity, and as part of a wider initiative to address British health authority requirements for post-marketing surveillance to identify possible short- and long-term risks associated with its use as a condition of marketing authorization, studies were undertaken to evaluate the safety of THC: CBDspray under clinical practice conditions. Methods: This prospective, observational, multicentre study reports on 205 patients with treatment-resistant MS spasticity who were prescribed THC: CBD spray as add-on therapy to existing antispasticity medications at 13 specialist MS centres across Spain. Safety evaluations were performed after 6 and 12 months’ exposure to THC: CBD spray. Results: Add-on THC: CBD spray was well tolerated during up to 12 months’ exposure. No new safety signals emerged and THC: CBD spray was not associated with any clinically-relevant occurrence of adverse events of special interest with cannabinoid-based medications such as falls requiring medical attention, psychiatric or psychotic symptoms, memory impairment, changes in driving ability, addiction or abuse. After 6 months’ and 12 months’ exposure, treating physicians considered that 139 patients (68% of original cohort) and 124 patients (60.5% of original cohort), respectively, were deriving sufficient anti-spasticity benefit from THC: CBD spray to warrant continued treatment. The mean dosage of THC: CBD spray (6.6 sprays/day) and carer requirements (~14.5 hours/day) remained stable throughout the study. Conclusions: THC: CBDspray as add-on therapy showed good tolerability and sustained anti-spasticity benefit in a relevant proportion (60.5%) of Spanish patients with MS-related spasticity treated for up to 12 months in everyday clinical practice.