IACM-Bulletin of September 26, 2010

Science — Cannabidiol beneficial in social anxiety disorder in a small clinical study

A small clinical study was conducted at the Division of Psychiatry of the University of São Paulo, Brazil, with 10 patients suffering from generalized social anxiety disorder. In the first session, subjects were given an oral dose of cannabidiol (CBD) (400 mg) or placebo, in a double-blind procedure. In the second session, the same procedure was performed using the drug that had not been administered in the previous session. Regional cerebral blood flow at rest was measured by an established method (Single Photon Emission Computed Tomography, SPECT) during each session.

Relative to placebo, CBD was associated with significantly decreased subjective anxiety. CBD also caused changes in regional cerebral blood flow. Researchers concluded that "these results suggest that CBD reduces anxiety in SAD [social anxiety disorder] and that this is related to its effects on activity in limbic and paralimbic brain areas."

(Source: Crippa JA, Derenusson GN, Ferrari TB, Wichert-Ana L, Duran F, Marti N-Santos RO, Simões MV, Bhattacharyya S, Fusar-Poli P, Atakan Z, Santos Filho A, Freitas-Ferrari MC, McGuire P, Zuardi AW, Busatto G, Hallak JE. Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report. J Psychopharmacol. 2010 Sep 9. [in press])

Science — Cannabis extract effective in bladder dysfunction in clinical study

At hospitals in the UK and Belgium 135 patients with multiple sclerosis and overactive bladder were included in a double-blind placebo-controlled, parallel-group trial to study the effect of the cannabis extract Sativex. During 8 weeks they received either the extract or a placebo.

There was only little difference between the cannabis extract and placebo on the primary endpoint, the reduction in daily number of urinary incontinence episodes from baseline to end of treatment. Four out of seven secondary endpoints were significantly in favour of Sativex: number of episodes of urinations (voids) during the night, overall bladder condition, number of voids/day and Patient's Global Impression of Change. Authors concluded: "Although the primary endpoint did not reach statistical significance, we conclude that Sativex did have some impact on the symptoms of overactive bladder in patients with MS, providing evidence of some improvement in symptoms associated with bladder dysfunction in these subjects."

(Source: Kavia RBC, De Ridder D, Constantinescu CS, Stott CG, Fowler CJ. Randomized controlled trial of Sativex to treat detrusor overactivity in multiple sclerosis. Mult Scler 2010 Sept 9 [in press])

UK — Re-thinking cannabis prohibition: proposals by a British cannabis expert

During the British Science Festival from 14 to 19 September 2010, Dr. Roger Pertwee, Professor of Neuropharmacology at the University of Aberdeen, suggested a change in cannabis policy. We need to discuss licensing the recreational use of cannabis, he said. "At the moment, cannabis is in the hands of criminals and I think it's kind of crazy. We're allowed to take alcohol. If it's properly handled, cannabis probably won't be more dangerous than that."

Professor Pertwee, who is an eminent expert on cannabis and cannabinoids for 40 years, is a former President of the International Cannabinoid Research Society and a former Chairman of the International Association for Cannabinoid Medicines. He says that a group should be set up with expert pharmacologists, lawyers and police, amongst others, to thrash out the issue. He wants the "social, ethical, legal and economic factors in addition to current medical and pharmacological" factors to be taken into account: "We need a better solution than we have now." "You need to avoid younger people taking it: perhaps have a minimum age of 21. You might have to have it licensed so that you can only take it if it's considered medically safe for you to do so. We have car licences, so why not cannabis licences?" he said. Professor David Nutt, former chairman of the Advisory Council on the Misuse of Drugs, said: "I welcome this attempt by the UK's leading expert on cannabis to bring rationality to the debate on its legal status."

More at:

- http://www.britishscienceassociation.org/web/news/FestivalNews/_Rethinkingcannabis.htm

- http://www.guardian.co.uk/science/2010/sep/14/cannabis-licence-legalisation-pertwee

(Sources: British Science Association, The Guardian of 14 September 2010)

News in brief

Science — Pain

Researchers of the University of Texas, USA, investigated the effects of THC (dronabinol) on the pain of 7 patients with spinal cord injury and neuropathic pain in a double-blind, crossover study. THC was compared with diphenhydramine as an active control. Change of pain did not differ between the two medications. Authors concluded that "on average, dronabinol was no more effective than diphenhydramine for relieving chronic neuropathic pain below the level of injury." (Source: Rintala DH, et al. Am J Phys Med Rehabil 2010;89(10):840-8.)

Austria — Conference

On 29 to 31 October 2010 the first Austrian Conference on Cannabis Medicine will be held during the hemp exhibition Cultiva. The speakers are Kurt Blaas, Sinisa Katanic, Marco van de Velde, Alfred Springer, Kathrin Höner Snoeken, Lutz Musner, Birgit Kraft, Lorenzo Nissen, Alexandra Dolezalova, Bernd Fiebich, Gabriela Hammel, René Kurz, Jörg Fachner, Rudolf Brenneisen, Christian Rätsch, Peter Rausch und William Courtney. More information at http://www.cultiva.at. (Source: Press release of 16 September 2010 by Cultiva)

USA — Michigan

There are increasing numbers of applications for a registration to use cannabis for medicinal purposes, representatives of the Michigan Department of Community Health said on 21 September. They received 56,513 applications for its registry of authorized users in the past 19 months, including new applications and renewals. It has a policy to approve or deny applications in 15 days. The health department is thousands of applications behind and now allows applicants who have waited at least 20 days to show a copy to law enforcement. (Source: Detroit Free Press of 22 September 2010)

USA — California

A coalition of medical cannabis advocates came out 21 September against a California ballot initiative that would legalize the drug for recreational use and tax its sales. Proposition 19 would inadvertently harm the most vulnerable patients by allowing local governments to prohibit the sale and purchase of cannabis in their cities, California Cannabis Association members said. In contrast, supporters of Proposition 19 said it explicitly protects the rights of patients and would provide them with safer and easier access to the drug by creating a strictly controlled, clearly defined legal system for cannabis cultivation, distribution and sales. (Source: Associated Press of 21 September 2010)

Spain — Call for legalisation

In Spain's most important newspaper, El País, the country's former drug commissioner, Araceli Manjón-Cabeza, called for an end to drug prohibition. Manjon-Cabeza's call for legalisation comes just a week after former Spanish Prime Minister Felipe González also called for drug legalisation. "Prohibitionism, installed in the United States at the beginning of the 20th Century, and imposed by that country on the rest of the planet, has failed," Manjon-Cabeza wrote. "There are multiple law enforcement and public health reasons that recommend legalization." (Source: El País of 22 September 2010)

Science — Pain

Scientists of the University of Clermont-Ferrand, France, demonstrated that the vanilloid-1-receptor is involved in the pain-relieving effects of acetaminophen. (Source: Mallet C, et al. PLoS One 2010;5(9). pii: e12748.)

Science — Pain

According to research at the University of California, USA, a blocker of anandamide degradation reduced pain in a rodent model of peripheral nerve injury and inflammation. This effect was mediated by activation of peripheral CB1 receptors. (Source: Clapper JR, et al. Nat Neurosci. 2010 Sep 19. [in press])

Science — Pain

According to research at the Virginia Commonwealth University in Richmond, USA, a selective CB2 receptor agonist (O-3223) reduced pain and inflammation in several animal models of pain without causing behavioural effects typical for CB1 receptor activation. (Source: Kinsey SG, et al. Neuropharmacology. 2010 Sep 14. [in press])

Science — THC and nabilone

According to research at the University of Kentucky, USA, THC and nabilone caused similar behavioural effects in 6 cannabis users who received different doses of nabilone (1, 2, 3, and 5 mg) and of THC (5, 10, 20, and 30 mg). Authors noted that this overlap of effects is "likely due to their shared mechanism as CB1 receptor agonists." (Source: Lile JA, et al. Clin Neuropharmacol. 2010 Sep 6. [in press])

Science — Endometriosis

Researchers at Florida State University in Tallahassee, USA, investigated the involvement of the endocannabinoid system in the pain associated with endometriosis. In a rat model they found that CB1 receptor agonists decrease, whereas CB1 receptor antagonists increase, endometriosis-associated hyperalgesia. They suggest that these observations provide "a novel approach for the development of badly-needed new treatments." Endometriosis is a medical condition in women in which endometrial-like cells appear in areas outside the uterine cavity. (Source: Dmitrieva N, et al. Pain. 2010 Sep 10. [in press])

Science — Bone marrow

According to research at Beth Israel Deaconess Medical Center, USA, endocannabinoids are expressed in bone marrow and play a role in the interaction of stem cells of the blood and the environment of bone marrow. (Source: Jiang S, et al. J Biol Chem. 2010 Sep 7. [in press])