IACM-Bulletin of February 18, 2007

Science — Cannabis effective in nerve pain associated with HIV

In a clinical study conducted at the San Francisco General Hospital in 50 HIV patients, who suffered from neuropathic pain, smoked cannabis resulted in a significant pain reduction compared with placebo. Patients were randomly assigned to two groups to smoke either cannabis (3.56 per cent THC, about 25 mg THC) or identical placebo cigarettes without cannabinoids three times daily for 5 days. All participants had experience with the use of cannabis. 31 used other pain medications and continued to use them throughout the study at stable doses, among them opioids and gabapentin.

Cannabis reduced daily pain by 34 per cent (median reduction) compared to 17 per cent with placebo. Greater than 30 per cent reduction in pain was reported by 52 per cent in the cannabis group and by 24 per cent in the placebo group. Cannabis also reduced pain in two kinds of experimentally induced pain and was not effective in a third model. Side effects were more common in the cannabis group. No serious adverse events were reported and no patient withdrew from the study due to side effects. Researchers concluded that "cannabis was well tolerated and effectively relieved chronic neuropathic pain from HIV-associated sensory neuropathy. The findings are comparable to oral drugs used for chronic neuropathic pain."

Neuropathic pain results from nerve damage. In this study the pain resulted from the HIV infection, from the drugs used to treat the infection or from both.

The abstract of the study is available at:

http://www.cannabis-med.org/studies/study.php

(Source: Abrams DI, Jay CA, Shade SB, Vizoso H, Reda H, Press S, Kelly ME, Rowbotham MC, Petersen KL. Cannabis in painful HIV-associated sensory neuropathy: A randomized placebo-controlled trial. Neurology 2007;68(7):515-21.)

USA — An administrative court recommends to the DEA to allow a Massachusetts professor to grow cannabis

Concluding that there is an inadequate supply of cannabis for medical research, an administrative law judge has recommended to the Drug Enforcement Administration (DEA) that it grant a Massachusetts professor's application to grow the drug. The judge's ruling of 12 February is nonbinding.

In June 2001, professor Lyle Craker submitted an application as a cannabis manufacturer to the DEA. However, the federal government limits the growing of cannabis available for clinical research to one source, the University of Mississippi. Federal officials said that Craker's university is free to compete for the next contract to produce cannabis for the United States. But there was no basis to add another producer. The company that wants to fund Craker's facility for growing cannabis countered that researchers are not getting the quantity or the quality of cannabis needed to conduct research that is approved by the Food and Drug Administration.

Judge Mary Ellen Bittner concluded that granting Craker's application would be in the public interest. Among the reasons she cited were inadequate competition and an inadequate supply of cannabis for research purposes. Steve Robertson, a spokesman for DEA, said the agency is reviewing Bittner's decision and would have no immediate comment.

(Source: Associated Press of 12 February 2007)

News in brief

USA — New Mexico

A proposal to allow certain patients to legally use cannabis under a state-run program passed the Senate on 7 February and headed to the House of Representatives. The proposal has the support of Governor Bill Richardson, who says he supports a bill "that includes proper safeguards to prevent abuse." (Source: The New Mexican of 8 February 2007)

USA — Minnesota

A bill was introduced to the House of Representatives on 5 February that would legalize the medical use of cannabis in Minnesota. A similar bill was recently introduced in the Senate. The language of the House bill would allow for "qualified" patients with a "registry identification card" to possess an "allowable" amount of medicinal cannabis for which they could not be arrested, prosecuted or penalized. (Source: Chaska Herald of 7 February 2007)

USA — Illinois

On 9 February a bill was introduced to the Senate that would remove criminal penalties for the medical use of cannabis with a physician's recommendation. (Source: Marijuana Policy Project of 9 February 2007)

Science — Cannabis and driving

The presence of THC or its metabolites in blood or urine was associated with a small increase in potentially unsafe driving actions in a large case-control study. Researchers used a database on all fatal traffic accidents in the USA and included data from 1993 to 2003 of drivers aged 20 to 49 years. The presence of cannabinoids was associated with an increased risk of 29 per cent compared to drug-free controls to show a potentially unsafe driving action (e.g. failure to obey signs). A blood alcohol concentration of 0.05 per cent was associated with an increased risk of 101 per cent, which increased to 206 per cent for a blood alcohol concentration of 0.1 per cent. (Source: Bedard M, et al. Can J Public Health 2007;98(1):6-11.)

Science — Epilepsy

In a model of status epilepticus with nerve cells of the hippocampus (a certain brain region) researchers at the Virginia Commonwealth University, USA, demonstrated that resistance was developed to benzodiazepines but not to a synthetic cannabinoid. Efficacy of the benzodiazepine lorazepam was high up to 30 minutes, but reduced to 10 to 15 per cent after one hour of the epileptic state. The efficacy of the cannabinoid WIN55,212-2 was not reduced for more than two hours. (Source: Deshpande LS, et al. Exp Neurol. 2007 Jan 9; [Electronic publication ahead of print])