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IACM-Bulletin of May 11, 2003


Science — THC effective in Tourette syndrome in a 6-week trial

A double-blind placebo-controlled study with 24 patients suffering from Tourette syndrome was conducted at the Medical School of Hannover, Germany. The 6-week trial confirmed results of two earlier short-term studies by Dr. Kirsten Mueller-Vahl and colleagues that THC is effective in the reduction of tics.

The Tourette syndrome is a complex neurological-psychiatric disorder characterized by motor tics (sudden spasms especially in the face, the neck and the shoulders) and one or more vocal tics. In many cases, it is associated with behavioural problems or psychopathologies (autoaggression, disturbed attention, etc.). Presently, neuroleptics are the most effective drugs. However, neuroleptics are not effective in all patients and in many cases, are not well tolerated.

Patients were treated over a period of 6 weeks. The dosage was titrated to the target dosage of 10 mg THC. Starting at 2.5 mg/day, the dose was increased by increments of 2.5 mg/day every 4 days. Tic severity was rated using several established scales.

Seven patients dropped out of the study or had to be excluded, but only one due to side effects. Application of THC resulted in a significant improvement of tic severity. No serious adverse effects occurred. Authors concluded that the “results provide more evidence that THC is effective and safe in the treatment of tics.”

(Source: Mueller-Vahl KR, Schneider U, Prevedel H, Theloe K, Kolbe H, Daldrup T, Emrich

HM. Delta-9-tetrahydrocannabinol (THC) is effective in the treatment of tics in Tourette syndrome: a 6-week randomized trial. J Clin Psychiatry 2003;64(4):459-465)

Science — Use of vaporizers reduces toxins from cannabis smoke

A new study has found that a vaporizer drastically reduces harmful gases in cannabis smoke, delivering a nearly pure stream of cannabinoids with very few by-products of combustion. Smoke of combusted cannabis usually contains similar toxins as tobacco smoke and smoke of other herbal material, which may damage tissues, resulting in chronic bronchitis and cancer.

The study, conducted by Chemic Labs in Canton, Massachusetts, analysed vapors from cannabis heated in the Volcano (manufactured by Storz & Bickel GmbH & Co. KG, Tuttlingen, Germany) and compared them to smoke produced by combusted cannabis. The Volcano is designed to heat material to temperatures of 130° to 230° Celsius where medically active vapors are produced, but below the threshold of combustion. Previous studies have found that vaporizers can reduce harmful toxins in cannabis smoke. However, this was the first study to analyze the gas phase of the vapor for a wide range of toxins.

The analysis showed that the Volcano vapor was remarkably clean, consisting 95% of THC with traces of cannabinol (CBN). The remaining 5% consisted of small amounts of three other components: one suspected cannabinoid relative, one suspected PAH (polycyclic aromatic hydrocarbon), and caryophyllene, a terpene. In contrast over 111 different components appeared in the gas of the combusted smoke, including a half dozen known PAHs. Non-cannabinoids accounted for as much as 88% of the total gas content of the smoke.

The study was sponsored by the US organisations California NORML, MAPS, and MPP. It used cannabis with a THC content of 4%. A quantitative analysis found that the Volcano delivered 46% of the THC into vapor following three 45-second exposures of the sample to the heat. In earlier studies typical efficiency of cannabis cigarettes was reported to be in the range of 15-40% for experienced users, and was 45% using a pipe.

Dr. Donald Abrams of the University of California, San Francisco, has submitted a grant proposal to the California Center for Medical Cannabis Research in San Diego to test the Volcano in a clinical study.

More information at

(Source: California NORML Press Release of 2 May 2003)

Canada — Government grown cannabis available for clinical trials

After months of confusion and delay, the federal government finally has a domestic supply of cannabis for research initiatives, Cindy Cripps-Prawak, head of the federal government's Cannabis Medical Access program, said.

The Health Ministry (Health Canada) is now getting the standardized quality it has been seeking since 2000, when it gave Prairie Plant Systems a $5.75-million contract to grow the cannabis in an abandoned mine at Flin Flon, Manitoba. The cannabis has a THC content of 10-15%, Ms. Cripps-Prawak said.

Presently, only two clinical trials on the safety and effective use of medical cannabis involving 64 patients are ongoing in Canada with material obtained from the USA. According to Health Canada new trials are expected to include up to 300-400 patients.

(Source: Ottawa Citizen of 3 May 2003)

News in brief

Switzerland — Director of Health Ministry for legalisation

In an interview the Director of the Health Ministry (Bundesamt fuer Gesundheit), Thomas Zeltner, supported the legalisation of cannabis use, but spoke out against legalisation of cultivation and sale of the drug. (Source: sda of 5 May 2003)

UK — British Medical Journal warning

In an editorial for the British Medical Journal Professor John Henry of Imperial College London and two colleagues warned that 30,000 Britains might die from smoking cannabis every year. They assumed that cannabis would be as harmful to the 3.2 million cannabis smokers as tobacco to the 13 million tobacco smokers, which would cause 120,000 tobacco related deaths (from cancer, heart diseases, etc). Besides this poorly substantiated speculation they claim that the “amount of the main active constituent, tetrahydrocannabinol (THC), in cannabis has increased from about 0.5% 20 years ago to nearer 5% at present in Britain” – which, however, is not true. Average THC concentrations of marijuana confiscated in the USA in 1983 was 3.3% and was similar in Europe. (Source: Henry JA, et al. BMJ 2003;326(7396):942-3)

USA — Steve McWilliams

Medical cannabis patient and activist Steve McWilliams of San Diego was sentenced to six months in prison by a federal court for the cultivation of cannabis in his garden despite a doctor's recommendation that allows him to use the drug. Many experts believe that McWilliams got a prison sentence because he was politically active regarding the legalization of medicinal cannabis. He will remain free on bail pending appeal. (Source: NORML of 1 May 2003)

Science — Ajulemic acid

It is known that the THC metabolite THC-COOH and the synthetic analogue of this metabolite, ajulemic acid (CT-3) inhibit inflammation, but the mode of action is unknown. This research shows that ajulemic acid activates a receptor called peroxisome proliferator-activated receptor gamma (PPARgamma). This is a potential mechanism for the anti-inflammatory action of the THC derivative. (Source: Liu J, et al. Mol Pharmacol 2003;63(5):983-92)