The pharmacological effects of inhaled cannabis on pain in patients with multiple sclerosis: risks versus rewards

Purpose Despite the fact that the risk versus benefit of smoking cannabis has not been extensively studied, many individuals with multiple sclerosis are smoking cannabis to reduce their pain intensity and spasticity. The lack of information about inhaled cannabis might be attributed to the fact that most trials focus on orally administered cannabis. Given the fact that the administration of cannabis via inhalation is known to rapidly deliver cannabinoids with a higher total bioavailability than what can be achieved through oral or buccal routes, it is important to understand the clinical trials conducted using smoked cannabis on patients with multiple sclerosis. Methods We sought to discuss the relevant literature about the safety and efficacy of smoked cannabis in multiple sclerosis patients in order to further understand the risks and benefits of this potential therapy for this patient population. Results The current knowledge about the potential effects of smoked cannabis on treating neuropathic pain associated with multiple sclerosis is reviewed. In addition, we discuss the possible adverse effects associated with smoking cannabis and we suggest safer as well as new effective inhaled cannabis formulations for the treatment of neuropathic pain associated with multiple sclerosis.