Analyzer workshop on the treatment of Parkinson's disease

State of the science: cannabis and cannabinoids in palliative medicine-the potential

Cannabinoids are chemicals derived naturally from the cannabis plant or are synthetically manufactured. They interact directly with cannabinoid receptors or share chemical similarity with endocannabinoids (or both). Within palliative medicine, cannabinoid receptors (CB1 and CB2) may modulate some cancer symptoms: appetite, chemotherapy-induced nausea and vomiting, and mood, pain and sleep disorders. Opioid and cannabinoid receptors have overlapping neuroanatomical receptor distribution, particularly at the dorsal horn, dorsal striatum and locus coeruleus. They have a favourable safety profile compared with opioids, and cannabis-based medicines help chronic pain. While cannabidiol (CBD) has anti-inflammatory properties, tetrahydrocannabinol (THC) is the psychoactive substance for issues such as mood and sleep. Nabiximols (Sativex), a CBD:THC combination, is Food and Drug Administration approved for some multiple sclerosis symptoms and epilepsy. There has been a swift societal evolution in attitudes about use of cannabis and cannabinoid medicines for chronic pain. In the USA, 33 states have now legalised prescription-based medical cannabis for several medical conditions; Canada has had legislation since 2001 authorising medical use. The European Union (EU) recently declared all EU citizens must have access to medical cannabis over the next 4 years. The integration into medicine and routine clinical use of cannabis is fraught with information gaps, regulatory issues and scarcity of research. Each patient should have a comprehensive assessment and risk-benefit discussion before any cannabis-based intervention to avoid possible complications such as hallucinations, psychosis and potential cardiac harm.

The effect of cannabis on tremor in patients with multiple sclerosis

BACKGROUND

Disabling tremor is common in patients with multiple sclerosis (MS). Data from animal model experiments and subjective and small objective studies involving patients suggest that cannabis may be an effective treatment for tremor associated with MS. To our knowledge, there are no published double-blind randomized controlled trials of cannabis as a treatment for tremor in MS patients.

METHODS

The authors conducted a randomized double-blind placebo-controlled crossover trial to examine the effect of oral cannador (cannabis extract) on 14 patients with MS with upper limb tremors. There were eight women and six men, with a mean age of 45 years and mean Expanded Disability Status Scale score of 6.25. Patients were randomly assigned to receive each treatment and the doses escalated over a 2-week period before each assessment. The primary outcome was change on a tremor index, measured using a validated tremor rating scale. The study was powered to detect a functionally significant 50% improvement in the tremor index. Secondary outcomes included accelerometry, an ataxia scale, spiral drawing, finger tapping, and nine-hole pegboard test performance.

RESULTS

Analysis of the data showed no significant improvement in any of the objective measures of upper limb tremor with cannabis extract compared to placebo. Finger tapping was faster on placebo compared to cannabis extract (p < 0.02). However, there was a nonsignificant trend for patients to experience more subjective relief from their tremors while on cannabis extract compared to placebo.

CONCLUSIONS

Cannabis extract does not produce a functionally significant improvement in MS-associated tremor.