Hepatitis C is a viral disease of the liver that afflicts an estimated four million Americans. Chronic hepatitis C is typically associated with fatigue, depression, joint pain and liver impairment, including cirrhosis and liver cancer.
Patients diagnosed with hepatitis C frequently report using cannabis to treat both symptoms of the disease as well as the nausea associated with antiviral therapy.[1-2] An observational study by investigators at the University of California at San Francisco (UCSF) found that hepatitis C patients who used cannabis were significantly more likely to adhere to their treatment regimen than patients who didn’t use it.[3]Nevertheless, no clinical trials assessing the use of cannabinoids for this indication are available in the scientific literature.
Preclinical data indicates that the endocannabinoid system may moderate aspects of chronic liver disease[4-5] and that cannabinoids may reduce inflammation in experimental models of hepatitis.[6] However, other clinical reviews have reported a positive association between daily cannabis use and the progression of liver fibrosis (excessive tissue build up) and steatosis (excessive fat build up) in select hepatitis C patients.[7-9]
As a result, experts hold divergent opinions regarding the therapeutic use of cannabinoids for hepatitis C treatment. Writing in the October 2006 issue of the European Journal of Gastroenterology, investigators from Canada and Germany concluded that cannabis’ “potential benefits of a higher likelihood of treatment success [for hepatitis c patients] appear to outweigh [its] risks.”[10] By contrast, other experts discourage the use of cannabis in patients with chronic hepatitis until further studies are performed.[11-15]
REFERENCES
[1] Schnelle et al. 1999. Results of a standardized survey on the medical use of cannabis products in the German-speaking area. Forschende Komplementarmedizin(Germany) 3: 28-36.
[2] David Berstein. 2004. “Hepatitis C – Current state of the art and future directions.” MedScape Today.
[3] Sylvestre et al. 2006. Cannabis use improves retention and virological outcomes in patients treated for hepatitis C. European Journal of Gastroenterology & Hepatology. 18: 1057-1063.
[4] Zamora-Valdes et al. 2005. The endocannabinoid system in chronic liver disease (PDF). Annals of Hepatology 4: 248-254.
[5] Gabbey et al. 2005. Endocannabinoids and liver disease – review. Liver International 25: 921-926.
[6] Lavon et al. 2003. A novel synthetic cannabinoid derivative inhibits inflammatory liver damage via negative cytokine regulation. Molecular Pharmacology 64: 1334-1344.
[7] Hezode et al. 2005. Daily cannabis smoking as a risk factor for progression of fibrosis in chronic hepatitis C. Hepatology 42: 63-71.
[8] Ishida et al. 2008. Influence of cannabis use on severity of hepatitis C disease.Clinical Gastroenterology and Hepatology 6: 69-75.
[9] Parfieniuk and Flisiak. 2008. Role of cannabinoids in liver disease. World Journal of Gastroenterology 14: 6109-6114.
[10] Fischer et al. 2006. Treatment for hepatitis C virus and cannabis use in illicit drug user patients: implications and questions. European Journal of Gastroenterology & Hepatology. 18: 1039-1042.
[11] Schwabe and Siegmund. 2005. op. cit.
[12] Hezode et al. 2005. op. cit.
[13] David Berstein. 2004. op. cit.
[14] Hezode et al. 2008. Daily cannabis use: a novel risk factor of steatosis severity in patients with chronic hepatitis C. Gastroenterology 134: 432-439.
[15] Purohit et al. 2010. Role of cannabinoids in the development of fatty liver (steatosis). The AAPS Journal 12: 233-237.