Daily marijuana use linked to liver fibrosis progression in HCV

Daily cannabis smoking of at least one marijuana cigarette per day in patients with chronic hepatitis C infection was strongly associated with liver fibrosis progression, according to a new French study of 211 patients presented at the annual meeting of the American Association for the Study of Liver Diseases. However, the study’s "occasional" cannabis smokers – those having less than one cigarette per day – had no increased risk of progression of fibrosis. Based on the findings, daily cannabis smoking should be avoided in patients with chronic hepatitis C. The daily cannabis smokers in the study were long-term users who averaged 16 years of daily marijuana intake. The study was "semiquantitative" because it’s difficult to know exactly how much cannabis is being smoked by patients.

In our cohort, the participants smoke pot as the rest of us may drink a glass of wine to casually relax and unwind. The cannabis smokers in the study were former intravenous drug users. According to some patients infected with hepatitis C virus (HCV) who are receiving interferon and ribavirin as antiviral therapy use marijuana to cope with the side effects of the treatment, which include nausea and loss of appetite. Studies say that cannabis helps. So if you are using cannabis for six months while you attempt to clear the virus, OK. However, if you are using it daily over the long term, then no, it is not advisable. Of the 150 men and 61 women in the study (mean age, 42 years), 32 percent were daily smokers and 51 percent were nonsmokers. All participants in the study were treatment – naïve and had a known duration of HCV infection. Chronic HCV infection was histologically proven in all study participants.

A multivariate analysis revealed that daily cannabis smokers were four times more likely to have a "rapid fibrosis progression rate" than occasional smokers and nonsmokers. The association between daily smoking and rapid fibrosis progression has "strong link." Rapid fibrosis progression was defined as a change in fibrosis status of greater than 0.08 fibrosis units per year. Doctor also observed that participants in the study who consumed "excessive" amounts of alcohol (>30 g/d) were 2.1 times more likely to have rapid fibrosis progression than those who drank less than that amount. These data from a colleague should be taken into account when counseling patients with chronic hepatitis C about marijuana use.

We don’t have evidence to date that [demonstrates the] use of marijuana for a limited period of time – say, the typical HCV treatment period of time – is hepatotoxic. However, these new data deserve frank discussion with patients. Marijuana’s potential benefit in modulation some of the side effects of antiviral and other drug therapies. There is a body of evidence that suggests if traditional treatment for alleviating side effects does not work, then cannabis can assist in managing nausea and loss of appetite. In the United States, CV infection is related to injection drug use in 60 percent of patients. Comorbid cannabis use is not uncommon (among these patients). Doctor also noted that marijuana use can alter the immune system, but that the impact of its use on interferon and ribavirin treatment was not known. Cannabis smoking has no impact on the liver in someone who does not have liver disease.