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IACM-Bulletin of May 24, 2009

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Europe/UK β€” GW Pharmaceuticals files for approval of Sativex for multiple sclerosis

The cannabis extract Sativex from the British company GW Pharmaceuticals has been filed for approval for the treatment of spasticity in multiple sclerosis in Europe, paving the way for its potential approval at the end of 2009 or early in 2010. Since the pivotal trial was designed largely by the British regulators there is relatively low risk of a rejection. The spray contains equal amounts of two natural cannabinoids, CBD (cannabidiol) and THC (dronabinol). Following numerous delays, the submission to regulators in Britain and Spain is a landmark for the British company.

Clinical trials have shown Sativex, which is sprayed under the tongue, reduces spasticity in multiple sclerosis patients who do not respond adequately to existing therapies. If it is approved, Sativex will be marketed in Britain by the German company Bayer and in the rest of Europe by the Spanish company Almirall. Following the filings in Britain and Spain, submissions for approval will be made in other European countries during 2010. Further clinical trials need to be completed before the medicine is ready for submission for approval in the United States, where GW's partner is the Japanese company Otsuka. Sativex was first approved in Canada in 2005.

More at:

- http://www.reuters.com/article/healthNews/idUSTRE54J1KI20090520

- http://www.gwpharm.com

(Sources: Press release of GW Pharmaceuticals of 20 May 2009, Reuters of 20 May 2009)

Science β€” THC improved symptoms of schizophrenia in a few patients in a clinical case series

Scientists at the Rockland Psychiatric Center in Orangeburg, New York, reported improvement of symptoms of schizophrenia in 4 patients who received oral THC (dronabinol). The study was initiated after a dramatic improvement in one patient. The researchers found that further 3 of 5 treatment-refractory patients with severe chronic schizophrenia but who had a self-reported history of improving with cannabis use improved also with THC. They only selected patients whose severe, refractory condition made the possible benefits outweigh the risks. From approximately 200 patients with chronic psychosis, 5 patients met the inclusion criteria. Dronabinol was initiated at 2.5 mg twice a day and subsequently raised to 5 mg twice a day at the second week and 10 mg twice a day at the just third week.

No significant adverse effects were observed. One of the patients needed 8 weeks to reach significant improvement, while the others responded within a shorter period of time. Researchers noted that "this improvement seems to have been a reduction of core psychotic symptoms in 3 of the 4 responders and not just non-specific calming." The results would suggest "that the role of cannabinoids in psychosis may be more complex than previously thought. They open a possible new role for cannabinoids in the treatment of schizophrenia."

(Source: Schwarcz G, Karajgi B, McCarthy R. Synthetic delta-9-tetrahydrocannabinol (dronabinol) can improve the symptoms of schizophrenia. J Clin Psychopharmacol 2009;29(3):255-8.)

Science β€” Moderate cannabis use was associated with improved retention in naltrexone treatment for opiate-dependence

According to clinical research at the Department of Psychiatry of Columbia University in New York moderate cannabis use improved retention in naltrexone treatment of patients suffering from dependency on opiates such as heroin. 63 opioid dependent patients, admitted for inpatient detoxification and induction onto oral naltrexone accompanied by six months of behavioural therapy were classified into three levels of cannabis use during treatment based on biweekly urine toxicology: abstinent (0 per cent cannabis positive urine samples); intermittent use (1 to 79 per cent cannabis positive samples); and consistent use (80 per cent or greater cannabis positive samples).

Naltrexone is an opioid receptor antagonist used primarily in the management of alcohol dependence and opioid dependence. Intermittent cannabis users showed superior retention in naltrexone treatment (median days retained = 133), compared to abstinent (median = 35 days) or regular users (median = 35 days). Intermittent cannabis use was also associated with greater adherence to naltrexone pill-taking. Researchers noted that experimental studies are needed to directly test the hypothesis that cannabinoid receptor agonists exert a beneficial pharmacological effect on naltrexone maintenance and to understand the mechanism.

(Source: Raby WN, Carpenter KM, Rothenberg J, Brooks AC, Jiang H, Sullivan M, Bisaga A, Comer S, Nunes EV. Intermittent marijuana use is associated with improved retention in naltrexone treatment for opiate-dependence. Am J Addict 2009;18(4):301-8.)

News in brief

USA β€” Rhode Island

Three years after legalizing cannabis for medicinal purposes in Rhode Island, the House of Representatives on 20 May adopted a plan to create dispensaries that would sell the drug to patients. The Senate in April overwhelmingly approved an identical version of the bill. Governor Carcieri, a long-time critic of medical cannabis, is expected to veto it. But the House of Representatives approved the legislation in a 63-to-5 vote, which should allow to easily override a veto later. (Source: Providence Journal of 21 May 2009)

USA β€” Minnesota

A bill that would have legalised the medicinal use of cannabis in Minnesota was approved by the state House of Representatives and the Senate on 18 May. However, the bill was vetoed by governor Tim Pawlenty on 22 May. (Source: Minneapolis Star-Tribune of 18 May 2009, MPP of 22 May 2009)

Canada β€” Department of Veterans Affairs

The Department of Veterans Affairs of the Canadian government will cover the costs of medical cannabis. A letter from the department to a veteran said the costs of medical cannabis provided by the health ministry (Health Canada) may be covered if it is proven to be needed for medicinal reasons. (Source: Comox Valley Record of 12 May 2009)

USA β€” End of war on drugs

Gil Kerlikowske, the new head of the White House Office of National Drug Control Policy, says the United States should not see itself as fighting a "war on drugs." He questioned the use of the popular "war" term, saying such an idea is actually standing in the way of positive movement regarding the country's drug problems. "Regardless of how you try to explain to people it's a 'war on drugs' or a 'war on a product,' people see a war as a war on them," Kerlikowske said on 13 May. (Source: UPI of 14 May 2009)

USA β€” California

The Supreme Court won't hear another challenge to California's law permitting cannabis use for medical purposes. On 18 May the high court refused to hear appeals from San Diego and San Bernardino counties. Representatives of the two counties had sued to overturn the state law after it was approved by voters in 1996, but lower courts have ruled against them. (Source: Associated Press of 18 May 2009)

Science β€” Amyotrophic lateral sclerosis

According to basic research with an animal model of amyotrophic lateral sclerosis (ALS), the sensitivity of cannabinoid-1 receptors controlling the transmission of the neurotransmitters glutamate and GABA was remarkably potentiated in ALS mice. Researchers noted that this may indicate that adaptations of the endocannabinoid system might be involved in the pathophysiology of ALS and that CB1 receptors might be potential therapeutic targets for this disease. (Source: Rossi S, et al. Amyotroph Lateral Scler 2009 May 19:1-8. [Electronic publication ahead of print])

Science β€” Tobacco and cannabis

Researchers of Columbia University in New York investigated differences between the effects of cannabis cigarettes mixed with tobacco and cannabis-only cigarettes in 24 cannabis users. On six different occasions they smoked cannabis cigarettes with three different THC concentrations (0, 1.8 and 3.6 per cent) with or without tobacco. Cannabis-only cigarettes resulted in higher THC blood concentrations and stronger psychic effects, while cannabis cigarettes mixed with tobacco produced similar increases in heart rate and higher carbon monoxide levels in the blood. (Source: Cooper ZD, et al. Drug Alcohol Depend 2009 May 13. [Electronic publication ahead of print])