Clinical Data for the Use of Cannabis-Based Treatments: A Comprehensive Review of the Literature

To compile and synthesize the available literature describing medical cannabis use across various disease states.

PubMed, EBSCO, and Google Scholar searches were conducted using MeSH and/or keywords.

Studies were included if they described the use of cannabis-based products and medications in the treatment of a predefined list of disease states in humans and were published in English. The extraction period had no historical limit and spanned through April 2019.

Evidence was compiled and summarized for the following medical conditions: Alzheimer disease, amyotrophic lateral sclerosis, autism, cancer and cancer-associated adverse effects, seizure disorders, human immunodeficiency virus, inflammatory bowel disease, multiple sclerosis (MS), nausea, pain, posttraumatic stress disorder, and hospice care.

Based on identified data, the most robust evidence suggests that medical cannabis may be effective in the treatment of chemotherapy-induced nausea and vomiting, seizure disorders, MS-related spasticity, and pain (excluding diabetic neuropathy). Overall, the evidence is inconsistent and generally limited by poor quality. The large variation in cannabis-based products evaluated in studies limits the ability to make direct comparisons. Regardless of the product, a gradual dose titration was utilized in most studies. Cannabis-based therapies were typically well tolerated, with the most common adverse effects being dizziness, somnolence, dry mouth, nausea, and euphoria.

As more states authorize medical cannabis use, there is an increasing need for high-quality clinical evidence describing its efficacy and safety. This review is intended to serve as a reference for clinicians, so that the risks and realistic benefits of medical cannabis are better understood.