IACM-Bulletin of April 10, 2011

Science — Cannabis may improve aspects of breathlessness in patients with chronic obstructive pulmonary disease according to a pilot study

British researchers investigated the effects of a cannabis extract on breathlessness in five healthy subjects and four patients with chronic obstructive pulmonary disease (COPD) in a double blind placebo-controlled crossover study. Subjects received sublingual cannabis extract (Sativex) or placebo. A maximum of 10.8 mg THC (dronabinol) and 10 mg CBD (cannabidiol) were given. Breathlessness was simulated using fixed carbon dioxide loads. Measurements taken were breathlessness (visual analogue scale and breathlessness descriptors), mood and activation, carbon dioxide tension and ventilatory parameters. These were measured at baseline and 2 hours post placebo and drug administration. Among descriptors of breathlessness are for example "My breathing is heavy," "I cannot get enough air," "I feel a hunger for air," "My chest is constricted."

Normal and COPD subjects showed no differences in breathlessness visual analogue scores and respiratory measurements before and after placebo or drug. After drug administration, COPD subjects picked 'air hunger' breathlessness descriptors less frequently compared to placebo. Authors concluded: "We have shown that breathlessness descriptors may detect an amelioration of the unpleasantness of breathlessness by cannabinoids without a change in conventional breathlessness ratings according to a visual analogue scale. A stimulus more specific for air hunger may be needed to demonstrate directly a drug effect on breathlessness."

(Source: Pickering EE, Semple SJ, Nazir MS, Murphy K, Snow TM, Cummin AR, Moosavi S, Guz A, Holdcroft A. Cannabinoid effects on ventilation and breathlessness: A pilot study of efficacy and safety. Chron Respir Dis. 2011 Mar 24. [in press])

On 1 April Poland’s lower house of parliament passed new legislation that gives prosecutors the option not to charge people detained with a small quantity of drugs. An amendment to the existing law was supported by 258 members of parliament with 159 votes against and six abstained. The new legislation allows prosecutors to end investigations if an individual possesses drugs for personal use only and is not a drug dealer. However, it does not specify what is considered a small quantity of drugs and maintains that possession of any amount of narcotics still remains illegal.

"The possession of any kind of drugs is illegal and is subject to punishment under the criminal code," Justice Minister Krzysztof Kwiatkowski stressed speaking in the parliament on 1 April. In cases involving larger amounts, the suspect is able to avoid prosecution by voluntarily agreeing to drug treatment therapy. Polish lawmakers claim the amended law allows prosecutors to focus more on drug dealers while creating more treatment options for drug addicts.

More at:

http://www.warsawvoice.pl/WVpage/pages/article.php/16244/news

(Source: The Warsaw Voice of 4 April 2011)

News in brief

USA — Montana

On 30 March the state Senate of Montana voted to repeal Montana's medical cannabis law and replace it by one with greater restrictions to make it much harder for people to get cards in the future authorizing them to use cannabis. In February, the House of Representatives had already supported the change. The bill is now expected to go before Governor Brian Schweitzer, a Democrat, who supports the existing medical cannabis program. (Source: Missoulian of 30 March 2011)

USA — Arizona

Arizonans now know what steps they must take before legally growing, selling or using medical cannabis according to the new Arizona state law. The Arizona Department of Health Services finished making its policy decisions regarding the medical cannabis rules and posted them on its web site. (Source: Eastern Arizona Courier of 3 April 2011)

USA — National Cancer Institute

Earlier in March the National Cancer Institute, a branch of the federal government’s National Institutes of Health, had posted a webpage, where the possible benefits of cannabis in fighting cancer tumours were mentioned. But a few days later the webpage was altered and the approving words deleted. The new webpage is still there, and still says cannabis has "potential benefits" for treating symptoms of cancer - a groundbreaking assertion for a government-affiliated organization. But the updated page deleted the potential anti-cancer effects of cannabis. (Source: Washington Times of 30 March 2011)

Science — HIV

At the Louisiana State University Health Sciences Center in New Orleans, USA, rhesus monkeys infected with SIV, which is the HIV equivalent in monkeys, were treated with different doses of THC. They showed dose-dependent reduced performance in several tests, but developed tolerance within 28 days and this tolerance was maintained during the following months. THC did not increase viral load in blood, cerebrospinal fluid or brain tissue compared to non-treated animals with SIV. Researchers concluded that "chronic THC produces tolerance to its behaviourally disruptive effects on complex tasks while not adversely affecting viral load or other markers of disease progression during the early stages of infection." (Source: Winsauer PJ, et al. Exp Clin Psychopharmacol 2011;19(2):154-72.)

Science — Huntington disease

According to research at the University Hospital Leuven, Belgium, in a rat model of Huntington disease there are early regional dysfunctions in endocannabinoid signalling in the brain. Authors noted that measurements of the CB1 receptor "may thus be a useful early biomarker for HD." (Source: Casteels C, et al. Exp Neurol. 2011 Mar 31. [in press])

Science — Multiple sclerosis

According to research with a mouse model of multiple sclerosis by Israeli scientists the natural cannabinoid cannabidiol (CBD) may be beneficial in MS. They observed that CBD administration during disease onset ameliorated the severity of the disease, which was accompanied by diminished axonal damage and inflammation as well as microglia activation. (Source: Kozela E, et al. Br J Pharmacol. 2011 Mar 30. [in press])

Science — Multiple sclerosis

At the University of Toronto, Canada, the effects of cannabis use on cognitive function were investigated in patients with multiple sclerosis. Two groups, each of 25 patients with MS (cannabis users and nonusers) performed a number of neuropsychological tests. Cannabis users performed significantly more poorly than nonusers on measures of information processing speed, working memory, executive functions, and visuospatial perception. They were also twice as likely as nonusers to be classified as globally cognitively impaired. Researchers concluded that "whatever subjective benefits patients may derive from using street cannabis (e.g., pain and spasticity relief) should be weighed against the associated cognitive side effects." (Source: Honarmand K, et al. Neurology 2011;76(13):1153-60.)

Science — Inflammatory bowel disease

Researchers of the University of Pavia, Italy, investigated the endocannabinoid content in the mucosa of patients with inflammatory bowel disease. The content of anandamide (AEA) but not of 2-AG (2-arachidonoyl-glycerol) was significantly lower in inflamed than in un-inflamed mucosa of these patients. This lower content was accompanied by a lower activity of the enzyme responsible for the synthesis of AEA and a higher activity of the AEA-degrading enzyme. (Source: Di Sabatino A, et al. Mucosal Immunol. 2011 Apr 6. [in press])

Science — Liver damage

In cell experiments delta-8-tetrahydrocannabivarin (delta-8-THCV) reduced liver damage after reduced blood supply to the liver partly by activation of the CB2 receptor. It reduced tissue injury and inflammation. Delta-8-THCV is a synthetic analogue of the plant cannabinoid delta-9-THCV. (Source: Bátkai S, et al. Br J Pharmacol. 2011 Apr 6. [in press])

Science — Brain

According to research at the University of Wollongong, Australia, regular cannabis use was associated with a decrease in white-matter volume of the cerebellum compared to non-users. There were no differences in grey matter of the cerebellum. (Source: Solowij N, et al. Psychol Med. 2011 Apr 5:1-11. [in press])

Science — Cancer of the bile duct

A group of researchers from the USA and China demonstrated that the endocannabinoid anandamide exerts anti-cancer actions on cancer of the bile duct by activation of the GPR55 receptor, a putative cannabinoid receptor. (Source: Huang L, et al. Lab Invest. 2011 Apr 4. [in press])

Science — Pain

According to animal studies at the University of Texas in San Antonio, USA, the transient receptor potential (TRP) channels may be involved in the peripheral pain-reducing effects of certain cannabinoids. In this investigation researchers used the synthetic cannabinoid ACEA. (Source: Ruparel NB, et al. Mol Pharmacol. 2011 Mar 25. [in press])