Adverse effects of cannabinoids

Epileptic Disord. 2020 Jan 1;22(S1):29-32. doi: 10.1684/epd.2019.1125.


Cannabidiol is a cannabinoid-derived product that has recently been approved for the treatment of pharmacoresistant seizures in patients with epileptic encephalopathies such as Dravet Syndrome and Lennox-Gastaut Syndrome. Short-term side effects of cannabidiol are well know and well-documented in the clinical trials that lead to its approval. Generally, is a well tolerated drug with transitory, dose-dependent mild to moderate effects like somnolence, decreased appetite or diarrhoea. However severe life-threatening reactions can also occur, and are often related to the non-controlled toxic combination with other antiseizure drugs that are widely used in this type of patients like sodium valproate or clobazam. In this brief review we summarize the available data about the short-term adverse events of cannabidiol. Further studies are required to assess the long-term outcome and final resolution of these conditions regarding safety of these patients.

Keywords: Epidiolex; Epidyolex; adverse reactions; cannabidiol; clinical trials; side effects.

MeSH terms

  • Anticonvulsants / adverse effects*
  • Anticonvulsants / therapeutic use
  • Cannabidiol / adverse effects
  • Cannabidiol / pharmacology
  • Cannabinoids / adverse effects*
  • Cannabinoids / pharmacology
  • Drug Resistant Epilepsy / drug therapy
  • Humans
  • Lennox Gastaut Syndrome / drug therapy*
  • Seizures / drug therapy*


  • Anticonvulsants
  • Cannabinoids
  • Cannabidiol