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IACM-Bulletin of September 9, 2012


Science/Human — Nabilone effective in the treatment of neuropathic pain in diabetes

Nabilone reduces pain in patients with diabetes suffering from peripheral neuropathic pain, which does not respond to other medication. This is the result of a double-blind, placebo-controlled study conducted at the Department of Clinical Neurosciences, University of Calgary, Canada. 37 patients were administered the synthetic cannabinoid nabilone for 4 weeks in addition to their current medication, of whom 26 achieved additional pain relief of more than 30 per cent and 11 were non-responders. Responders were included in a further 5-week double-blind treatment period, where 13 received flexible-dose nabilone (1-4 mg/day) and 13 a placebo.

For nabilone responders, there was an improvement in the change of neuropathic pain (mean treatment reduction of 1.27 on a visual analogue scale). The average nabilone dose at end of treatment was 2.9 mg a day. There were also significant improvements compared to placebo for anxiety, sleep and quality of life measured by standard questionnaires. Researchers concluded that “flexible-dose nabilone 1-4mg/day was effective in relieving DPN symptoms, improving disturbed sleep, quality of life, and overall patient status. Nabilone was well tolerated and successful as adjuvant in patients with DPN.”

Toth C, Mawani S, Brady S, Chan C, Liu C, Mehina E, Garven A, Bestard J, Korngut L. An enriched-enrolment, randomized withdrawal, flexible-dose, double-blind, placebo-controlled, parallel assignment efficacy study of nabilone as adjuvant in the treatment of diabetic peripheral neuropathic pain. Pain. 2012 Aug 22. [in press]

Science/Human — Cannabis use by adults does not cause reduction of intelligence

Even heavy cannabis use does not cause cognitive decline in adults. However, heavy use of the drug during adolescence may result in reduced intelligence in later life. These are the main results of a long-term study conducted by an international research team in New Zealand. Participants were members of the Dunedin Study, a study of a birth cohort of 1,037 individuals followed from birth in the years 1972/1973 to age 38 years. Cannabis use was ascertained in interviews at ages 18, 21, 26, 32, and 38 years. Neuropsychological testing was conducted at age 13 years, before initiation of cannabis use, and again at age 38 years.

Researchers found that those who persistently used cannabis - smoking it at least four times a week year after year through their teens, 20s and, in some cases, their 30s - suffered a decline in their IQ. The more that people smoked, the greater the loss in IQ. The effect was only noticed in those who started smoking cannabis as adolescents. “It is such a special study that I'm fairly confident that cannabis is safe for over-18 brains, but risky for under-18 brains,” Professor Terrie Moffitt from the Institute of Psychiatry, King's College London, a member of the research team told BBC News. „The results are good news for all patients, who use cannabis-based medicines,” Franjo Grotenhermen, Chairman of the German Association for Cannabis as Medicine, said in a press release by the ACM. “A moderate cannabis use such as with medical use as well as the use of the drug by adults does not result in measurable impairment.”

Meier MH, Caspi A, Ambler A, Harrington H, Houts R, Keefe RS, McDonald K, Ward A, Poulton R, Moffitt TE. Persistent cannabis users show neuropsychological decline from childhood to midlife. Proc Natl Acad Sci U S A. 2012 Aug 27. [in press]

BBC News of 28 August 2012

Reuters of 27 August 2012

Pressemitteilung der ACM vom 30. August 2012

USA — Attempt to close cannabis dispensaries in Los Angeles stopped by citizens of the town

According to a report by the Wall Street Journal a ban on cannabis dispensaries in Los Angeles won't go into effect after advocates for medical cannabis successfully petitioned to block it. After years of failed attempts to control the number of cannabis shops, the Los Angeles City Council passed an ordinance in late July that made these dispensaries illegal.

Now, medical cannabis advocates submitted about 50,000 signatures to overturn the ban, nearly twice the number needed, according to the Los Angeles City Clerk's office. Once the city clerk verifies the signatures, the council will have to decide whether to repeal the ordinance or place the issue on the ballot next year. Although many California cities ban cannabis sales to patients, about 50 towns allow sales, while regulating things like the number of dispensaries, their locations and hours of operation.

Wall Street Journal of 5 September 2012

News in brief

Science/Human — Higher relapse rate in cannabis dependence with concomitant tobacco use

In a study with 51 cannabis users (mean use of 10 cannabis cigarettes a day), who wanted to quit use, those who also used tobacco had a higher likelihood of relapse. Researchers concluded that “current cigarette smoking is a clinically important marker for increased risk of marijuana relapse.”

New York State Psychiatric Institute and Department of Psychiatry, Columbia University, New York, USA.

Haney M, et al. Biol Psychiatry. 2012 Aug 29. [in press]

Science/Animal — Inhibition of endocannabinoid degradation reduces pain

The injection of a substance that inhibits the activity of the enzyme MAGL, which is responsible for the degradation of the endocannabinoid 2-AG (2-arachidonoylglycerol), into the spinal cord reduced pain transmission in rats.

School of Biomedical Sciences, University of Nottingham Medical School, UK.

Woodhams SG, et al. Br J Pharmacol. 2012 Aug 26. [in press]

Science/Human — Oral THC reduces withdrawal symptoms of cannabis users

In a study with 13 daily cannabis users high doses of oral THC (60 and 120 mg a day) attenuated cannabis withdrawal. Researchers propose oral THC (dronabinol) for the treatment of dependency from inhaled THC (dronabinol).

Johns Hopkins University School of Medicine, Baltimore, USA.

Vandrey R, et al. Drug Alcohol Depend. 2012 Aug 22. [in press]

Science/Animal — Oxytocin reduces pain, which involves the CB1-receptor

The body-own substance oxytocin, which was administered into the brain, reduced pain in mice, and this effect was mediated at least in part by the CB1-receptor, since this effect was blocked by a CB1-receptor antagonist. Researchers also demonstrated the involvement of the opioid system.

Department of Experimental Pharmacology, University of Naples "Federico II", Italy.

Russo R, et al. Peptides. 2012 Aug 10. [in press]

Science/Animal — High anandamide levels cause fat storage due to reduced thyroid function

Mice without FAAH (fatty acid amide hydrolase), which is responsible for the degradation of anandamide develop hypothyroidism (reduced function of the thyroid gland). This reduced function causes increased fat storage and insulin resistance, i.e. reduced response of cells to insulin.

Yale School of Medicine, New Haven, USA.

Brown WH, et al. Proc Natl Acad Sci U S A. 2012 Aug 21. [in press]

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