Sativex reduces neuropathic pain due to multiple sclerosis
British researchers of the Walton Centre for Neurology and Neurosurgery in Liverpool demonstrated that the cannabis extract Sativex of GW Pharmaceuticals is effective in reducing central neuropathic pain and sleep disturbance in people with multiple sclerosis (MS). "Central neuropathic pain occurs frequently in people with MS. It can be tremendously debilitating and unresponsive to existing therapies," Dr Carolyn Young, principal investigator of the study, said.
The 5 week placebo-controlled study was conducted in 66 patients with MS who suffered from chronic neuropathic pain. 64 patients completed the trial, of whom 32 received the cannabis extract and 32 the placebo. Sativex contains equal amounts of THC and cannabidiol (CBD) and is administered as a spray under the tongue. The mean maximum daily THC dose was 25 mg (range: 5-65 mg). Pain and sleep disturbance were recorded daily on an 11-point numerical rating scale. Cannabis caused a significant mean pain reduction of 2.7 points (baseline: 6.5) compared with 1.4 points (baseline: 6.4) following placebo. Sleep was significantly improved by 2.5 points with cannabis compared to 0.8 points with placebo. The cannabis extract was generally well tolerated, although more patients on cannabis than placebo reported dizziness, dry mouth, and somnolence.
Based on these study results, which were published now in the journal Neurology, Sativex was approved as a prescription medicine in Canada for the symptomatic relief of neuropathic pain in adults with MS and is available in pharmacies since 20 June 2005.
Sources:www.cannabis-med.org; Rog DJ, Nurmikko TJ, Friede T, Young CA. "Randomized, controlled trial of cannabis-based medicine in central pain in multiple sclerosis". Neurology 2005;65(6):812-9; press release by GW Pharmaceuticals of 27 September 2005)