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IACM-Bulletin of July 14, 2013

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Science/Human — Cannabis may decrease symptom severity of opiate withdrawal during methadone maintenance treatment

A new study suggests that symptoms of opiate withdrawal decrease in patients undergoing methadone maintenance treatment, who use cannabis. The study with 91 patients has been conducted by researches of the Farber Institute for Neurosciences at Thomas Jefferson University in Philadelphia, USA. Patterns of cannabis use prior to and during methadone maintenance treatment (MMT) were examined to assess possible cannabis-related effects on MMT, particularly during methadone stabilization.

Rates of cannabis use were high during methadone induction, dropping significantly following dose stabilization. History of cannabis use correlated with cannabis use during MMT but did not negatively impact the methadone induction process. Authors noted that “pilot data also suggested that objective ratings of opiate withdrawal decrease in MMT patients using cannabis during stabilization.”

Scavone JL, Sterling RC, Weinstein SP, Van Bockstaele EJ. Impact of Cannabis Use during Stabilization on Methadone Maintenance Treatment. Am J Addict 2013;22(4):344-51.

Science/Human — Cannabis use does not accelerate progression of liver disease in people with hepatitis C according to a longitudinal study

In a prospective study with 690 people positive for HIV and hepatitis C virus (HCV) the use of cannabis did not accelerate progression to significant liver fibrosis. The study was conducted at the Department of Epidemiology, Biostatistics and Occupational Health of McGill University in Montreal, Canada. Researchers assessed the association between the average number of cannabis cigarettes smoked per week and progression to significant liver fibrosis, cirrhosis or end-stage liver disease. At baseline, 53% had smoked cannabis in the past 6 months, consuming a median of 7 joints per week (range: 1-21); 40% smoked daily.

They found no evidence for an association between cannabis smoking and significant liver fibrosis progression in HIV/HCV coinfection. Each 10 additional joints per week smoked slightly increased the risk of progression to a clinical diagnosis of cirrhosis and end-stage liver disease (hazard ratio: 1.13). However, when exposure was lagged to 6-12 months before the diagnosis, cannabis was no longer associated with clinical disease progression. This suggests “that reverse causation due to self-medication could explain previous results,” authors wrote. Smaller previous studies had found an association between cannabis use and progression to liver fibrosis in patients with hepatitis C.

Brunet L, Moodie EE, Rollet K, Cooper C, Walmsley S, Potter M, Klein MB; for the Canadian Co-infection Cohort Investigators. Marijuana Smoking Does Not Accelerate Progression of Liver Disease in HIV-Hepatitis C Coinfection: A Longitudinal Cohort Analysis. Clin Infect Dis. 2013 Jul 4. [in press]

News in brief

Holland — Medicinal Cannabis Masterclass

Bedrocan BV is offering its 3rd Medicinal Cannabis Masterclass, September 22-25 in Wageningen, the Netherlands. Scheduled to coincide with the IACM's 7th Conference on Cannabinoids in Medicine (Sept. 27-28 in Cologne, Germany), the course is 3.5 days of comprehensive instruction on the pharmaceutical application of herbal cannabis as regulated by the Dutch Ministry of Health, Welfare, and Sport. Organized by Dr. Arno Hazekamp (Bedrocan), speakers include Dr. Mark Ware, Dr. Jon Page, Dr. Jahan Marcu, and others. The course is capped at 12 participants. Deadline to apply is August 1.

Information on Cannabis Masterclass

Science/Human — The risks of cannabis smoking for the lungs are much lower than that of tobacco smoking

According to a review by Dr. Donald Tashkin, a professor at the University of California in Los Angeles “the accumulated weight of evidence implies far lower risks for pulmonary complications of even regular heavy use of marijuana compared with the grave pulmonary consequences of tobacco.” Smoking cannabis may be associated with chronic bronchitis, but studies do not substantiate claims that it is positively associated with the development of lung cancer, chronic obstructive pulmonary disease (COPD), or emphysema.

University of California at Los Angeles, USA.

Tashkin DP. Ann Am Thorac Soc 2013;10(3):239-47.

Italy — Sativex now available

GW Pharmaceuticals announced that their cannabis spray Sativex is now available in Italy as a prescription medicine for use in the treatment of spasticity in multiple sclerosis. Sativex is now available in several European countries including the UK, Spain and Germany.

Press release by GW Pharmaceuticals of 8 July 2013

USA — /Mexico: Former Mexican president Fox urges cannabis legalization

Former Mexican President Vicente Fox took his activities to legalize cannabis to San Francisco, joining cannabis advocates to urge the United States and his own country to decriminalize the sale and recreational use of cannabis. Fox met for three hours with the advocates, including Steve DeAngelo, an Oakland-based executive director of California's largest cannabis dispensary, and former Microsoft executive Jamen Shively, who hopes to create a Seattle-based cannabis brand now that Washington state has legalized recreational use.

Reuters of 9 July 2013

Science/Human — Proteins identified, which may be responsible for allergies to cannabis

Several proteins in the cannabis plant were identified, which were thought to be responsible for the allergies to cannabis in 23 patients. Among the putative allergens are several enzymes of the plant.

Centers for Disease Control and Prevention, Morgantown, West Virginia, USA.

Nayak AP, et al. Ann Allergy Asthma Immunol 2013;111(1):32-37.

Science/Cells — Cannabinoids may be useful against transplant rejection

In cell experiments with cannabinoids that act on the CB2 receptor data were collected that “support the potential of this class of compounds as useful therapies to prolong graft survival in transplant patients” by inhibiting T-cells.

Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, USA.

Robinson RH, et al. J Neuroimmune Pharmacol. 2013 Jul 4. [in press]

Science/Human — Reduced dopamine synthesis capacity in cannabis users

Scientists compared dopamine synthesis capacity in 19 regular cannabis users with 19 nonusers. Cannabis users had reduced dopamine synthesis capacity in a certain brain region (striatum). Authors concluded that “chronic cannabis use is associated with reduced dopamine synthesis capacity and question the hypothesis that cannabis increases the risk of psychotic disorders by inducing the same dopaminergic alterations seen in schizophrenia.”

Institute of Clinical Sciences, Hammersmith Hospital, Imperial College London, United Kingdom.

Bloomfield MA, et al. Biol Psychiatry. 2013 Jun 29. [in press]

Science/Human — Endocannabinoids influence blood clotting

The endocannabinoids 2-AG and virodhamine induced platelet aggregation, while anandamide was inactive. This effect was independent of cannabinoid receptors. Authors concluded that “pharmacological CB1- and CB2-receptor ligands will not affect platelets and platelet-dependent progression and complications of cardiovascular diseases.”

Institute for Prevention of Cardiovascular Diseases, Ludwig Maximilians University of Munich, Germany.

Brantl SA, et al. Platelets. 2013 Jun 21. [in press]

Science/Cells — Cannabinoids induce death of pancreatic cancer cells

Cannabinoids, which bind to the CB1 and the CB2 receptor impaired the production of energy of pancreatic cancer cells and this resulted “in a strong induction of autophagy [cell degradation] and in the inhibition of cell growth.”

Department of Life and Reproduction Sciences, University of Verona, Italy.

Dando I, et al. Cell Death Dis. 2013 Jun 13. [in press]

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