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IACM-Bulletin of March 2, 2003


Science UK β€” Cannabis extracts effective in reducing pain and spasticity

A THC rich cannabis extract, a cannabidiol (CBD) rich extract and a cannabis extract with a CBD/THC ratio of 1:1 were effective in symptoms of 24 patients, of whom 18 suffered from multiple sclerosis, four from spinal cord injury, one from brachial plexus damage and one from limb amputation.

The study was conducted as consecutive series of double-blind, placebo-controlled single-patient cross-over trials with two-week treatment protocols at hospitals in Oxford as part of studies by GW Pharmaceuticals. The trials started with an open label period where patients received the CBD/THC extract to get familiar with the procedure and to ensure they could tolerate the extract.

Three patients withdrew from the study due to side effects during the open label period and one patient did not complete all treatment periods. In the 20 patients who completed the study there was a significant improvement of pain with the CBD extract compared to placebo assessed with visual analogue scales, a significant improvement of pain, spasm, spasticity and appetite with the THC extract, and a significant improvement of spasm and sleep with the CBD/THC extract. Impaired bladder control was improved in some patients with this symptom.

Scientists concluded that "cannabis medicinal extracts can improve neurogenic symptoms unresponsive to standard treatments. Unwanted side effects are predictable and generally well tolerated."

(Source: Wade DT, Robson P, House H, Makela P, Aram J. A preliminary controlled study to determine whether whole-plant cannabis extracts can improve intractable neurogenic symptoms. Clin Rehabil 2003;17:18-26)

World β€” INCB criticizes governments who want to decriminalize cannabis

The International Narcotics Control Board (INCB) of the United Nations (UN) criticized Britain for the downgrading of cannabis to a low risk category, saying it had led to "worldwide repercussions... including confusion and widespread misunderstanding." INCB President Philip Emafo said groups advocating legalisation or decriminalisation of drugs were misguided: "Governments should not be intimidated by a vocal minority that wants to legalise illicit drug use."

In a Message from the President accompanying the Report of the INCB for 2002 of 26 February Emafo said: "Cannabis is not a harmless drug as advocates of its legalization tend to portray. Cannabis use affects the functioning of the brain. Its illicit use is also associated with heart attacks in some young people and can cause lung disease and cancer."

The Netherlands based Transnational Institute accused Emafo of being out of touch with developments in international drug control. According to the institute Emafo is ignoring the adoption of harm reduction strategies by several U.N. agencies. Such policies "have proven more effective than the zero-tolerance the INCB is advocating."

(Sources: Report of the INCB for 2002 of 26 February 2003, INCB – Message from the President of 26 February 2003, Reuters of 26 February 2003, UN Wire of 27 February 2003)

News in brief

USA β€” Montana

On 26 February the Montana House of Representatives dismissed a bill that would have allowed seriously ill people to use marijuana in a 60-40 vote. The House Judiciary Committee had approved the bill a week before week on a 13-5 vote. But some committee members said they changed their minds after thinking about the message it would send kids. (Source: Associated Press of 26 February 2003)

Science β€” Pain

It is known that the analgesic effects of opioids are enhanced by THC in animals. In a new study researchers demonstrated that the enhancement to either morphine or codeine produced by THC was greater than simply additive in mice. Researchers conclude: "These findings suggest that the use of a low-dose combination of analgesics is a valid and effective approach for the treatment of pain and necessitates further study." (Source: Cichewicz DL, McCarthy EA. J Pharmacol Exp Ther 2003 Mar;304(3):1010-5)

Science β€” Tolerance to morphine

Tolerance to morphine was reduced by co-administration of THC in mice. Chronic treatment with high dose oral morphine produced a threefold tolerance of pain-reducing effects. Tolerance to morphine was prevented in groups receiving a daily co-treatment with a non-pain-relieving dose of THC. In separate experiments researchers demonstrated that mice treated chronically with morphine were not cross-tolerant to THC. "In summary, co-treatment with a combination of morphine and Delta-9-THC may prove clinically beneficial in that long-term morphine efficacy is maintained." (Source: Cichewicz DL, Welch SP. J Pharmacol Exp Ther 2003 Feb 11.)

Science β€” Nausea

In a rat model of nausea THC and the synthetic cannabinoid HU-210 prevented these effects in rats. The cannabinoid effects seem to be mediated by CB1 receptors. (Source: Parker LA, et al. Psychopharmacology (Berl) 2003 Mar;166(2):156-62)

Science β€” Neuropsychological performance

During a study on the efficacy of dronabinol (THC) in 24 patients with Tourette syndrome who received up to 10 mg THC daily for 6 weeks neuropsychological performance. During medication and immediately as well as 5-6 weeks after cessation of treatment, no detrimental effects were seen on performance (e.g. learning, recall of word lists, visual memory, divided attention). (Source: Muller-Vahl KR, et al. Neuropsychopharmacology 2003 Feb;28(2):384-8)