IACM-Bulletin of May 14, 2006

Science — Cannabis effective in reducing postoperative pain

The efficacy and safety of a capsulated cannabis extract (Cannador) to treat postoperative pain was investigated in a multi-centre study of twelve British centres. Cannador is standardized on the content of THC and other cannabinoids. Three single doses (5, 10 and 15 mg THC) were administered after post-surgical patients had decided to stop patient-controlled analgesia and if oral pain treatment was indicated. Patients were allowed to ask for additional pain treatment if the cannabis extract was not effective enough.

The arm with 5 mg THC was stopped after 11 patients were included, since all patients asked for additional pain treatment within less than six hours after administration of the cannabis extract, and therefore this dose was regarded as insufficient. The arm with 10 mg THC was completed until the intended number of 30 patients. 50 per cent (15 of 30) of patients required additional medication within six hours. The arm with 15 mg THC was stopped after the inclusion of 24 patients, when the last patient suffered a serious side effect (drop of blood pressure, pallor, slowed heart rate). 25 per cent (6 of 24) of this group needed additional pain medication. Side effects were usually mild even in the highest dose group. The patient who suffered from drop of blood pressure and slowed heart rate recovered rapidly without medication.

Researchers concluded that "the optimal dose was determined to be 10 mg Cannador because it was effective in providing pain relief at rest without serious or severe side effects in a fit adult group of post-surgical patients."

(Source: Holdcroft A, Maze M, Dore C, Tebbs S, Thompson S. A multicenter dose-escalation study of the analgesic and adverse effects of an oral cannabis extract (Cannador) for postoperative pain management. Anesthesiology 2006;104(5):1040-1046)

After intense pressure from the United States, President Vicente Fox has asked Congress to reconsider a law it passed at the end of April that would decriminalize the possession of small amounts of drugs.

In a statement issued on 3 May, Mr. Fox said the law should be changed "to make it absolutely clear that in our country the possession of drugs and their consumption are and continue to be crimes." Officials from the U.S. State Department and the White House’s drug control office met with the Mexican ambassador in Washington on 1 May and expressed grave reservations about the law, saying it would draw tourists to Mexico who want to take drugs and would lead to more consumption, said Tom Riley, a spokesman for the U.S. Office of National Drug Control Policy.

Mexico’s chief of the Federal Police, Eduardo Medina Mora, the main architect of the first measure, which Mr. Fox sent to Congress in January, said it was true the law would make it a misdemeanour to possess small quantities of illegal drugs, but he added that people caught with those drugs would still have to go before a judge and would face a range of penalties. The current law has a provision allowing people arrested on charges of possessing drugs to argue they are addicts and that the drugs were for personal use. The new law sets an upper limit on how much of each drug one could possess and still claim to be using it due to a dependency, Mr. Medina Mora said.

(Source: New York Times of 3 May 2006)

Science — Moderate cannabis use not harmful to the brain of adolescents, Magnetic Resonance Imaging study finds

Researchers of the Nathan S. Kline Institute for Psychiatric Research and the New York University School of Medicine scanned the brains of 10 individuals who were frequent cannabis users in adolescence and 10 control subjects with advanced Magnetic Resonance Imaging (MRI) methods. They found no "evidence of cerebral atrophy or loss of white matter integrity" and concluded that "frequent cannabis use is unlikely to be neurotoxic to the normal developing brain."

The former cannabis users were now aged 18 to 27 years and had used cannabis between daily to 2-3 times weekly for one or more years during adolescence, but were currently abstinent. They were compared to subjects of similar age and sex who never used cannabis. Measurements were obtained of whole brain and certain brain areas, which are most often related to psychotic experiences and memory.

Scientists noted, that their "data are preliminary and need replication with larger numbers of subjects, although they do have implications for refuting the hypothesis that cannabis alone can cause a psychiatric disturbance such as schizophrenia by directly producing brain pathology."

The article is available for download at http://www.harmreductionjournal.com/content/3/1/17

(Source: Delisi LE, Bertisch HC, Brown K, Majcher M, Bappal A, Szulc KU, Ardekani BA. A preliminary DTI study showing no brain structural change associated with adolescent cannabis use. Harm Reduct J 2006;3(1):17 [electronic publication ahead of print])

USA — Oregon Supreme Court ruled that an employer was allowed to fire a worker who used medical cannabis

The Oregon Supreme Court ruled on 4 May that an employer didn't break state disability laws by firing a worker who used medical cannabis. The case involves Robert Washburn, a millwright, who was fired after failing drug tests. Washburn had a state-issued card allowing him to use cannabis to ease leg spasms that disrupted his sleep.

He used the drug at home and not during work, but the company fired him in 2001. A circuit court decision said the state medical cannabis law doesn't require employers to "accommodate the medical use of marijuana in the workplace." However, the Oregon Court of Appeals disagreed, saying the test results didn't establish that Washburn had used the drug at work. In his ruling, the Supreme Court now said Washburn's impairment did not rise to the level of a disability under state law since his previous medication had successfully treated his condition and therefore he was not forced to use cannabis.

(Source: Associated Press of 4 May 2006)

News in brief

France — Cannabis consumption

According to the drug experts Astrid Fontaine and Michel Hautefeuille cannabis consumption is on a steady rise among managers, bankers, business leaders and high-level office employees. (Source: ANSA of 3 May 2006)

Science — Plea for reclassification

In an editorial Dr. George Lundberg, Editor of MedGenMed and Adjunct Professor of Health Policy, Harvard School of Public Health, Boston, plead for a reclassification of cannabis in the USA, so that its medical use would be alowed. "In fact, enforcement of unrealistic laws regarding marijuana has probably caused more harm than marijuana itself. Although far from harmless by toxicologic or pathologic criteria, marijuana is much less dangerous than many other substances in less restrictive schedules, like morphine and cocaine, not to mention the unscheduled legal mass killers tobacco and alcohol. Of course, marijuana does have proven medical usefulness for some conditions. People obey laws they believe to be just; they do not obey the marijuana laws because they know they are unjust, even absurd." (Source: Lundberg GD. MedGenMed 2005;7(3):47)

Science — Ulcer of the stomach

A synthetic cannabinoid (ACEA) that selectively binds to the CB1 receptor inhibited the formation of stomach ulcers in rats. Acetylsalicylic acid (Aspirin) caused lesions in the gastric mucosa within three hours that were dose-dependently decreased by the cannabinoid. This effect is thought to be caused by a reduction of acid secretion. (Source: Rutkowska M, et al. Pharmazie 2006;61(4):341-2)