IACM-Bulletin of May 20, 2012

Science/Human — Smoked cannabis reduces symptoms of multiple sclerosis

A clinical study of 30 adult patients with multiple sclerosis at the University of California in San Diego has shown that smoked cannabis may be an effective treatment for spasticity. The placebo-controlled trial also resulted in reduced perception of pain. Principal investigator Dr Jody Corey-Bloom and colleagues randomly assigned participants to either the intervention group (which smoked cannabis once daily for three days) or the control group (which smoked identical placebo cigarettes). After an 11-day interval, the participants crossed over to the other group.

"We found that smoked cannabis was superior to placebo in reducing symptoms and pain in patients with treatment-resistant spasticity, or excessive muscle contractions," said Corey-Bloom. The trial used an objective measurement, a modified Ashworth scale which graded the intensity of muscle tone. Pain was measured using a visual analogue scale. The researchers also looked at physical performance and cognitive function and asked patients with regard to psychological effects. Cannabis was generally well tolerated and had only mild effects on attention and concentration. The current study is the fifth clinical test of the possible efficacy of cannabis for clinical use reported by the University of California Center for Medicinal Cannabis Research (CMCR). Four other human studies also reported positive results.

Free full text:

- http://www.cmaj.ca/content/early/2012/05/14/cmaj.110837.long

More at:

- http://www.sciencedaily.com/releases/2012/05/120514122607.htm

- http://www.reuters.com/article/2012/05/14/us-marijuana-sclerosis-idUSBRE84D0RS20120514

Source: Corey-Bloom J, Wolfson T, Gamst A, Jin S, Marcotte TD, Bentley H, Gouaux B. Smoked cannabis for spasticity in multiple sclerosis: a randomized, placebo-controlled trial. CMAJ. 2012 May 14. [in press].

Science/Human — Cannabidiol similar effective in schizophrenia as standard anti-psychotic medication

Clinical research at the University of Cologne with 42 patients suffering from acute schizophrenia shows that CBD significantly reduces psychopathological symptoms, when compared to the initial status. Half of them received 800 mg of oral CBD (cannabidiol) daily for four weeks and the other half the standard medicinal drug amisulpride, a potent antipsychotic, in a double-blind manner. Results, first presented at the IACM Conference in Leiden in 2005, were now published in a medical journal.

Either treatment was safe and led to significant clinical improvement, but CBD presented with significant less adverse effects. Moreover, cannabidiol treatment was accompanied by a significant increase in blood anandamide levels. Anandamide is an endocannabinoid produced by the body. “The results suggest that inhibition of anandamide deactivation may contribute to the antipsychotic effects of cannabidiol potentially representing a completely new mechanism in the treatment of schizophrenia,” authors wrote.

Free full text:

http://www.nature.com/tp/journal/v2/n3/full/tp201215a.html

Source: Leweke FM, Piomelli D, Pahlisch F, Muhl D, Gerth CW, Hoyer C, Klosterkötter J, Hellmich M, Koethe D. Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia. Transl Psychiatry 2012 March 20. [in press].

News in brief

Science/Animal — CBD is a glycine receptor agonist

Researchers investigated the mechanisms, by which CBD (cannabidiol) reduces inflammatory and neuropathic pain in animals. They found that the cannabinoid-induced analgesic effect is absent in mice lacking glycine receptors and concluded that this receptor mediates suppression of chronic pain. Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, and Chemical Biological Research Branch, National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD 20892.

Source: Xiong W, et al. J Exp Med. 2012 May 14. [in press].

USA — New York high court judge with cancer uses cannabis

A cancer-stricken judge in New York has become a voice in support of legalizing the use of medical cannabis with the admission that he smokes the drug to ease the side-effects of his treatments. Brooklyn Supreme Court Justice Gustin Reichbach, who is being treated for pancreatic cancer, wrote in a New York Times article that he had been using cannabis at "great personal risk" to help him cope with the nausea, sleeplessness and loss of appetite from chemotherapy treatments.

Source: Reuters of 17 May 2012.

Europe — Approval of Sativex in ten more European countries expected

Following previous positive regulatory submissions in the UK, Spain, Germany, Italy, Denmark Sweden, Austria, and the Czech Republic, the cannabis extract Sativex is expected to receive approval for the treatment of spasticity in multiple sclerosis in ten additional European countries. The countries involved are: Belgium, Finland, Iceland, Ireland, Luxembourg, the Netherlands, Norway, Poland, Portugal and Slovakia.

Source: GW Pharmaceuticals of 8 May 2012.

USA — Cannabis dispensaries may open in Rhode Island

The Rhode Island House of Representatives endorsed legislation that supporters say should allow medical cannabis dispensaries to open without the fear of federal prosecution. The measure now heads to Governor Lincoln Chafee, who is expected to sign it into law. Once that happens dispensaries could be open within several months. Under the bill, dispensaries would be allowed to possess up to 1,500 ounces of cannabis. The proposal would also allow law enforcement to inspect dispensaries.

Source: Associated Press of 16 May 2012.

Science/Human — Legal highs contain new synthetic cannabinoids

Researchers compared the type of synthetic cannabinoids in Spice and other preparations known as “legal highs” in older and newer samples. Older samples contained JWH-018, JWH-073, JWH-200, CP-47,497 and CP-47,497-C8, which are now forbidden in the USA. However, 95.1 per cent of newer samples contained other cannabinoids that are currently not regulated.

AIT Laboratories, Indianapolis, IN 46241.

Source: Shanks KG, et al. J Anal Toxicol. 2012 May 14. [in press].

Science/Human — THC renders fearful faces less fearful

THC impaired recognition of fear and anger in faces, but it only marginally impaired recognition of sadness and happiness. These results show that THC reduces perception of facial threat. Nevertheless, THC does not appear to positively bias evaluation of emotional stimuli in general. This is the result of a study with healthy subjects who received either oral THC (7.5 and 15 mg) or a placebo across separate sessions before performing tasks assessing facial emotion recognition.

Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA. Source: Ballard ME, et al. J Psychopharmacol. 2012 May 13. [in press].

Science/Cells — Abnormal CBD enhances humour outflow in the eye

Abnormal CBD may be beneficial in glaucoma since it enhanced humour outflow from the eye. This is the result of experimental research using tissues from pigs. This effect was not mediated by known cannabinoid receptors.

Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40292, United States of America.

Source: Qiao Z, et al. Exp Eye Res. 2012 May 8. [in press].

Science/Animal — Reduced level of CB1 receptors increases memory of fearful events

Mice without CB1 receptors were more fearful than normal mice in situations, which previously had caused anxiety. “CB1 deficiency leads to enhanced contextual fear memory and altered synaptic plasticity in the hippocampus, supporting the key role of endocannabinoid signalling in learning and memory, in particular following highly aversive encounters,” authors wrote.

Max Planck Institute of Psychiatry, Kraepelinstrasse 2, 80804 Munich, Germany.

Source: Jacob W, et al. Neurobiol Learn Mem. 2012 May 8. [in press].