Should gastroenterologists prescribe cannabis? The highs, the lows and the unknowns

Abstract

Cannabis, commonly known as marijuana, is a drug extracted from the Cannabis plant known for its psychotropic and medicinal properties. It has been used for healing purposes during ancient times, although its psychoactive components led to its restricted use in medicine. Nonetheless, cannabis is found to have modulatory effects on the endocannabinoid system exhibiting its medicinal role in the gastrointestinal (GI) system. Emerging animal and human studies demonstrate the influential effects of cannabis on a variety of GI diseases including inflammatory bowel disease, motility disorders and GI malignancies. It also has a regulatory role in GI symptoms including nausea and vomiting, anorexia, weight gain, abdominal pain, among others. However, both its acute and chronic use can lead to undesirable side effects such as dependency and addiction, cognitive impairment and cannabinoid hyperemesis syndrome. We will discuss the role of cannabis in the GI system as well as dosing strategies to help guide gastroenterologists to assess its efficacy and provide patient counseling before prescription of medical marijuana.

Keywords: Endocannabinoid system; Gastrointestinal disorders; Marijuana; Side effects; cannabis.

Figure 1

Different routes of cannabisy.

Figure 2

Role of cannabis on the gastrointestinal tract. GI: Gastrointestinal; IBD: Inflammatory bowel disease; IBS: Irritable bowel syndrome; GERD: Gastroesophageal reflux disease; CB1: Cannabinoid receptor type 1; CB2: Cannabinoid receptor type 2.

Figure 3

Pathway of cannabis hyperemesis syndrome. CNS: Central nervous system; THC: Tetrahydrocannabinol; CBD: Cannabidiol; CB1: Cannabinoid receptor type 1; CB2: Cannabinoid receptor type 2.

Figure 4

Algorithm to prescribe or not to prescribe cannabis. ¹Gastrointestinal (GI) disorders and symptoms: Inflammatory Bowel Disease, Motility, Ileus, Irritable Bowel Syndrome, Abdominal pain, GI cancer-related pain, Gastroesophageal Reflux Disease, Non-cardiac chest pain, Nausea and Vomiting, Anorexia, Obesity. ²Discuss patient goals individually, and risks and benefits of cannabis before initiation.