Contents

• Issue 46 December 09
• Money Well Spent
• Cannabis
• The Woolshed and After
• Peer Education
• HBVaccine
• Great Liver Food
• A Strategy for Hepatitis B
• Sharing Ideas in Beautiful Hobart
• Mascot Madness
• Vending Machine Trial
• Open Your Mind
• Love Your Liver Lunch
• eBox Update

Cannabis

Recent research on using cannabis and the effects it has on people living with hepatitis C has uncovered some interesting data. While long-term frequent cannabis use may be detrimental to people with chronic hepatitis C, making liver fibrosis worse, other research has shown that medicinal use of cannabis during interferon-based therapy can relieve side effects and help patients stay on treatment, thereby improving their chances of sustained response. Here and over the page we present the results of these studies.

Study 1

The management of side-effects from the treatment of hepatitis C can often be difficult. Many patients turn to cannabis for relief, based on widespread anecdotal evidence of its pain-reducing effects. Unfortunately, until now, there has been little research into cannabis use and its effect on treatment outcomes.

Enter a study published recently in the European Journal of Gastroenterology and Hepatology. Entitled ‘Cannabis use improves retention and virological outcomes in patients treated for hepatitis C’, it provides a valuable starting point for future research.

“To define the impact of cannabis use during hepatitis C treatment, we conducted a prospective observational study of standard interferon and ribavirin treatment in 71 recovering substance users, of whom 22 (31%) used cannabis and 49 (69%) did not,” explain the report’s authors, headed by Diana Sylvestre of the Department of Medicine in the University of California and the Organization to Achieve Solutions in Substance-Abuse (OASIS), California.

Of these 71 patients, 17 stopped therapy early. Of these, only one was a user of cannabis. “Overall, 37 patients, or 52% were end-of-treatment responders, 14 (64%) of them cannabis users and 23 (47%) non-users.”

A total of 21 out of the initial 71 (30%) had a sustained virological response: 12 of the 22 cannabis users (54%) and nine of the 49 non-users (18%), which corresponds to a post-treatment virological relapse rate of 14% in the cannabis users and 61% in the non-users. Overall, 48 (68%) were adherent, 29 (59%) non-users and 19 (86%) cannabis users.

So what does this mean? “Although cannabis users were no more likely than non-users to take at least 80% of the prescribed interferon or ribavirin, they were significantly more likely to remain on HCV treatment for at least 80% of the projected treatment duration (95% versus 67%).”

It’s important to note here that use of cannabis is usually viewed far more seriously by the legal authorities in the United States, where this study was conducted, than it is in South Australia. As the authors note, “illicitly obtained marijuana ... may be highly variable in its content of bioactive compound, leaving in question a true quantitation of the amount of cannabis that may or not be beneficial. Significant limitations are introduced by our observational study design; however, with legal proscriptions against cannabis use limiting its study, the design and conduct of randomised, prospective research studies is virtually impossible at this time.”

The researchers concluded that “our results suggest that the modest use of cannabis does not appear to impact negatively upon HCV treatment outcomes and need not elicit undue alarm. The widespread use of illicit cannabis during HCV therapy highlights the inadequacies of our current side-effect management strategies; our study suggests that cannabis use may offer benefit for some patients undergoing HCV treatment by helping them maintain adherence to the frequently debilitating medication regimen.

“However, the mechanisms through which cannabis exerts its benefit are unclear, and controlled studies may further elucidate the mechanisms through which cannabis may impact upon clinical outcomes during HCV treatment..”

The full report of this research is available at www.waitingtoinhale.org/science_news/cannabis_hepc.pdf.

Study 2

Daily marijuana use may contribute to the progression of liver fibrosis in people with chronic hepatitis C, according to a report published last year in the journal Clinical Gastroenterology and Hepatology.

Researchers from the University of California at San Francisco interviewed 204 patients with chronic hepatitis C between 2001 and 2004, assessing demographic characteristics, HCV risk factors, and their use of cannabis and alcohol.

Participants underwent virological testing and liver biopsies, which were scored according to the Ishak system, which measure liver fibrosis in stages from F0 to F6. In this scale, F0 indicates no fibrosis, F1 minimal and F2 mild fibrosis, and F3 to F6 indicate increasingly severe fibrosis. Of the study participants, 27.5% were rated F0, 55.4% F1 to F2, and 17.2% were rated F3 to F6.

The median age of the study participants was 47 years. 69% were men, 49% were white, 21% were co-infected with HIV, most were in the low-income bracket, and for 70% the presumed route of HCV infection was injection drug use. The median lifetime duration of alcohol use was 29 years, with a median of about 2 drinks per day. Obviously there was a lot of variation in the lifestyle factors of this test’s subjects.

Regarding marijuana, 13.7% of the participants reported daily cannabis use within the past 12 months, 45.1% reported occasional use, and 41.2% said they never used marijuana.
Daily cannabis use was not strongly associated with mild (F1-F2) fibrosis compared with absent (F0) fibrosis. However, daily cannabis use (compared with occasional or no use) was strongly associated with moderate to severe (F3-F6) fibrosis.

Other independent predictors of moderate to severe fibrosis were a greater lifetime duration of moderate or heavy alcohol use, and a greater number of portal tracts (these are islands of connective tissue containing branches of the portal vein and hepatic artery, running side by side, that bring blood to the liver, as well as containing bile ducts, which carry bile in the opposite direction to the blood flow) in the liver.

Independent predictors of mild fibrosis were a higher HCV viral load, and a medium or high number of portal tracts. However, age, sex, race, duration of HCV infection, HCV genotype, HIV status, body weight, tobacco use, and lifetime alcohol use were not significantly associated with mild fibrosis.

In conclusion, the researchers wrote that “daily cannabis use is strongly associated with moderate to severe fibrosis.” They recommended that “HCV-infected individuals should be counselled to reduce or abstain from cannabis use.”