IACM-Bulletin of January 6, 2008

Science — Daily cannabis use increases the risk of liver fibrosis in patients with hepatitis C

According to research at the University of California at San Francisco daily cannabis use was associated with moderate to severe liver fibrosis in 204 patients with hepatitis C. Between 2001 and 2004, participants underwent interviews to assess demographic data, risk factors for HCV, and use of cannabis and alcohol. In addition, virologic testing and liver biopsy was performed. The median age of the group was 46.8 years, 69 per cent were male, 49 per cent were white. Cannabis use frequency within prior 12 months was daily in 13.7 per cent, occasional in 45.1 per cent, and never in 41.2 per cent. There was no fibrosis in 27.5 per cent, mild fibrosis in 55.4 per cent and moderate to severe fibrosis in 17.2 per cent of subjects.

Current daily cannabis use increased the odds of moderate to severe fibrosis by nearly 7-fold. There was no association between current daily cannabis use and mild fibrosis. A major limitation of the study is the method, since only one examination was performed, which limits the ability to establish a temporal relationship between cannabis use and fibrosis stage. However, the study confirms an earlier French study of 2004, in which daily cannabis use was also associated with an increased risk for liver fibrosis. Authors conclude that "HCV-infected individuals should be counseled to reduce or abstain from cannabis use."

More at:

http://www.natap.org/2006/AASLD/AASLD_07.htm

To find more information on cannabinoids and liver fibrosis you may search previous IACM-Bulletins with the keyword "fibrosis" at:

http://www.cannabis-med.org/english/home.htm

or directly at:

http://www.cannabis-med.org/english/bulletin/iacm.php

(Source: Ishida JH, Peters MG, Jin C, Louie K, Tan V, Bacchetti P, Terrault NA. Influence of cannabis use on severity of hepatitis C disease. Clin Gastroenterol Hepatol 2008;6(1):69-75)

News in brief

USA — Prison population

The United States, home of the world's largest prison population, could save 20 billion US dollars a year and cut that population in half by adopting a handful of systemic reforms, including decriminalizing drug possession, said a prestigious group of social scientists in a report with the title "Unlocking America". Of 100,000 citizens 737 are imprisoned in the USA, compared to 607 in Russia, 487 in Cuba and 98 in Germany (in the years 2004 or 2005). The report is available online at: http://www.jfa-associates.com/publications/#srs. (Sources: JFA of November 2007, Telepolis of 27 December 2007)

Europe — Cannabis use

According to the recent annual report of the EMCDDA (European Monitoring Centre for Drugs and Drug Addiction) the use of cannabis increased in the 1990s. "However,

some of the more recent data suggest that the upward trend is levelling off, albeit at historically high levels." According to the report "estimates suggest that more than 23 million European adults have used cannabis in the last year, producing an average figure of about 7 % of all 15- to 64-year-olds." The use by children below the age of 15 is very low. The Annual Report 2007 is available in 23 languages on the website of the EMCDDA (http://www.emcdda.europa.eu/). (Source: EMCDDA)

Science — Pain

According to animal research at the University of Calgary, Canada, pain reducing effects of cannabinoids are increased in animals with arthritis compared to healthy animals. (Source: Schuelert N & McDougall JJ. Arthritis Rheum 2007;58(1):145-153.)

Science — Cancer

Researchers of the University of Rostock, Germany, investigated the mechanisms by which cannabinoids reduce the invasion of cancer cells into surrounding tissues. Human cancer cells were treated with THC or a synthetic cannabinoid (methanandamide) and cell invasion through a gel was measured. Suppression of cell invasion by cannabinoids was concentration-dependent with a decrease of invasion by the lowest dose of THC (10 nM) of 68 per cent. Researchers concluded that "cannabinoids may therefore offer a therapeutic option in the treatment of highly invasive cancers." (Source: Ramer R & Hinz B. J Natl Cancer Inst 2007 Dec 25 [Electronic publication ahead of print])