The current state of the research on marijuana and its constituent cannabinoids suggests the potential for therapeutic value for a number of conditions.
The U.S. National Institutes of Health (NIH) supports efforts to find potential therapeutic value of cannabinoids for a variety of conditions and symptoms.
These three studies have suggested potentially valuable therapeutic effects of marijuana or its components in several areas.
Pain/Spasticity: Nabiximols (trade name Sativex), which contains THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol) in equal proportions, has been approved throughout most of Europe and in a number of other countries for the treatment of spasticity and pain associated with multiple sclerosis (MS). Multiple recent studies have confirmed that nabiximols (Sativex) reduced the severity of spasticity in MS patients, including two studies recently presented at the European Committee for Treatment and Research in Multiple Sclerosis annual meeting. Sativex has not been approved in the United States, where it is being developed for the treatment of refractory pain in cancer patients; two recent Phase 3 clinical trials did not achieve the expected clinical endpoint.
Two recent reviews, one in the Journal of the American Medical Association and another by the American Academy of Neurology concluded that there is moderate evidence to suggest that some cannabinoids, including nabiximols, may be beneficial for the treatment of chronic neuropathic or cancer pain and spasticity due to MS, and strong evidence for the efficacy of oral cannabis extract for spasticity and pain associated with MS. In contrast, they also concluded that there was insufficient evidence for the use of cannabinoids in the treatment of involuntary movement disorders such as Huntington’s disease or Tourette’s syndrome.
Pediatric Epilepsy: A number of case studies and anecdotal reports, as well as a few small randomized clinical trials (RCTs), have also suggested that CBD may reduce seizures in children with treatment-resistant epilepsy. GW Pharmaceuticals is currently conducting two placebo-controlled, multicenter Phase III studies examining Epidiolex, a formulation of CBD, for both Dravet syndrome and Lennox-Gastaut syndrome, severe forms of pediatric epilepsy. According to company press releases in March and June 2016, initial results from the first Phase 3 trials of Epidiolex were positive. The first trial showed a median reduction in monthly convulsive seizures of 39 percent among patients with Dravet syndrome who took Epidiolex compared with 13 percent for placebo. The second trial showed a median reduction in monthly drop seizures of 44 percent among patients with Lennox-Gastaut syndrome who took Epidiolex compared with 22 percent for placebo. Insys Therapeutics has developed synthetic CBD and Phase 2/3 studies are underway. In May 2016, they reported successful completion of a Phase 1/2 safety and pharmacokinetic (PK) study in pediatric subjects with treatment-resistant epilepsy.
Post-traumatic Stress Disorder: Human laboratory studies have also suggested that THC administration may help facilitate fear extinction in healthy subjects which could have implications for treating patients with post-traumatic stress disorder (PTSD). RCTs are currently ongoing that will examine the therapeutic value of smoked cannabis and dronabinol for patients with PTSD.
