Background: Central pain in multiple sclerosis (MS) is common and often refractory to treatment. Methods: We conducted a single-center, 5-week (1-week run-in, 4-week treatment), randomized, double-blind, placebo-controlled, parallel-group trial in 66 patients with MS and central pain states (59 dysesthetic, seven painful spasms) of a whole-plant cannabis-based medicine (CBM), containing delta-9-tetrahydrocannabinol:cannabidiol (THC:CBD) delivered via an oromucosal spray, as adjunctive analgesic treatment. Each spray delivered 2.7 mg of THC and 2.5 of CBD, and patients could gradually self-titrate to a maximum of 48 sprays in 24 hours. Results: Sixty-four patients (97%) completed the trial, 34 received CBM. In week 4, the mean number of daily...

Objectives—To identify the types and frequencies of pain treatments used by individuals with cerebral palsy (CP); examine the perceived effectiveness of these treatments; and identify the types of healthcare providers that were accessed for pain-related services. Design—A cross-sectional survey design was employed. 83 adults (mean age=40.3 years, SD=13.6) with CP indicated their pain location and intensity during the past 3 months. Next, they indicated their use of 24 different pain treatments and the effectiveness of each. Finally, participants indicated the frequency of pain-related healthcare visits to specific providers over the past 6 months. Results—63% of participants reported experiencing chronic pain and rated their pain...

Evidence for an analgesic interaction between delta-9-tetrahydrocannabinol (Δ9 -THC) and morphine was sought using an experimental pain model applied to normal volunteers. The study incorporated a double blinded, four treatment, four period, four sequence, crossover design. Subjects received Δ9 -THC 5 mg orally or placebo and 90 min later morphine 0.02 mg/kg intravenously or placebo. Fifteen minutes later subjects rated the pain associated with the application of thermal stimuli to skin using two visual analog scales, one for the sensory and one for the affective aspects of pain. Among sensory responses, neither morphine nor Δ9 -THC had a significant effect at the doses used,...

The recently discovered endocannabinoid system (ECS), which includes endocannabinoids and the proteins that metabolize and bind them, has been implicated in multiple regulatory functions both in health and disease. Several studies have suggested that ECS is centrally and peripherally involved in the processing of pain signals. This finding is corroborated by the evidence that endocannabinoids inhibit, through a cannabinoid type-1 receptor (CB1R)-dependent retrograde mechanism, the release of neurotransmitters controlling nociceptive inputs and that the levels of these lipids are high in those regions (such as sensory terminals, skin, dorsal root ganglia) known to be involved in transmission and modulation of pain signals. In this...

Abstract The analgesic properties of exogenous cannabinoids have been recognized for many years and suggest a regulatory role for the endogenous cannabinoid ("endocannabinoid") system in mammalian nociceptive pathways. The endocannabinoid system includes: (1) at least two families of lipid signaling molecules, the N-acyl ethanolamines (e.g., anandamide) and the monoacylglycerols (e.g., 2-arachidonoyl glycerol); (2) multiple enzymes involved in the biosynthesis and degradation of these lipids, including the integral membrane enzyme fatty acid amide hydrolase; and (3) two G-protein coupled receptors, CB1 and CB2, which are primarily localized to the nervous system and immune system, respectively. Here, we review recent genetic, behavioral, and pharmacological studies that...