Effect of Medicinal Cannabis Therapy (MCT) on Severity of Chronic Low Back Pain, Sciatica and Lumbar Range of Motion

Abstract

Background: Anecdotal evidence indicates the possible efficacy of cannabis use as an adjunctive treatment in chronic low back pain. The purpose of the current study was to assess the results of treatment of patients suffering from chronic low back pain by medicinal cannabis (MCT). Methods: A cohort of 46 patients was followed for a minimum of twelve months. They were evaluated at baseline prior to MCT, 3 months later when MCT was begun and up to 12 months of MCT by patient reported outcome questionnaire (SF-12), visual analogue scale (VAS) and the Brief Pain Inventory (BPI), back specific function was assessed using the Oswestry score, range of motion was measured using the Saunders digital inclinometer. Opiate use was assessed using pharmacy dispensation records at baseline and after 12 months of MCT. Inclusion criteria included: Age over 25 years, sciatica with documented treatment for at least 12 months, evidence on CT or MRI scan of disc herniation or spinal stenosis, failure of at least two narcotic drugs, and consent to use medicinal cannabis. Exclusion criteria included evidence of bone cancer, evidence of diabetic neuropathy, and evidence of prior psychotic reactions. Treatment protocol: Cannabis usage was at a fixed dosage of 20 grams per month, dose increase was considered at least after 6 months of treatment. The cannabis was smoked at a recommended rate of 4 dosages per day. Results: After 12 months of MCT BPI VAS decreased from 8.4 ± 1.4 to 2.0 ± 2.0; SF12-PCS improved from 47 ± 14 to 55 ± 12; SF12-MCS improved from 44 ± 6 to 50 ± 10; and sagittal plane active range of motion improved from 34º ± 8º degrees to 48º ± 8º, Conclusion: Short term usage of smoked medicinal cannabis appear to improve both physical and mental function while decreasing pain levels of chronic low back pain sufferers.