Meta-analysis of cannabis based treatments for neuropathic and multiple sclerosis-related pain
Review published: 2007.
Quality assessment
The review concluded that cannabinoids, including the cannabidiol/delta-9-tetrahydrocannabinol buccal spray, are effective in treating neuropathic pain in patients with multiple sclerosis. However, given the limitations of the evidence presented, the reliability of the authors? conclusions is uncertain. Full critical summary
Abstract
OBJECTIVE: Debilitating pain, occurring in 50-70% of multiple sclerosis (MS) patients, is poorly understood and infrequently studied. We summarized efficacy and safety data of cannabinoid-based drugs for neuropathic pain.
DATA SOURCES: Studies were identified from Medline, Embase, and Cochrane databases; Bayer Healthcare provided additional trials.
STUDY SELECTION: Accepted were randomized, double-blinded placebo-controlled trials of cannabinoid-based treatments for MS-related/neuropathic pain in adults > or = 18 years of age.
DATA EXTRACTION: Two reviewers identified studies and extracted data; a third adjudicated disagreements. Data included baseline and endpoint pain scores on visual analog or 11-point ordinal scales.
DATA SYNTHESIS: Of 18 articles and three randomized controlled trial (RCT) reports identified, 12 articles and two reports were rejected (9 = inappropriate disease or outcome, 1 = duplicate, 1 = review, and 1 = abstract); six accepted articles and one RCT-report involved 298 patients (222 treated, 76 placebo); four examined Sativex (a cannabidiol/delta-9-tetrahydrocannabinol (THC) buccal spray) (observations = 196), five cannabidiol (n = 41), and three dronabinol (n = 91). Homogeneity chi(2) values were non-significant, allowing data combination. Analyses focused on baseline-endpoint score differences. The cannabidiol/THC buccal spray decreased pain 1.7 +/- 0.7 points (p = 0.018), cannabidiol 1.5 +/- 0.7 (p = 0.044), dronabinol 1.5 +/- 0.6 (p = 0.013), and all cannabinoids pooled together 1.6 +/- 0.4 (p < 0.001). Placebo baseline-endpoint scores did not differ (0.8 +/- 0.4 points, p = 0.023). At endpoint, cannabinoids were superior to placebo by 0.8 +/- 0.3 points (p = 0.029). Dizziness was the most commonly observed adverse event in the cannabidiol/THC buccal spray arms (39 +/- 16%), across all cannabinoid treatments (32.5 +/- 16%) as well as in the placebo arms (10 +/- 4%).
CONCLUSION: Cannabinoids including the cannabidiol/THC buccal spray are effective in treating neuropathic pain in MS.
LIMITATIONS: This review was based on a small number of trials and patients. Pain related to MS was assumed to be similar to neuropathic pain.
CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.
