IACM-Bulletin of January 9, 2005

Science — THC improves spasticity in multiple sclerosis in long-term study

First results of a follow-up study of the largest ever conducted clinical study of THC and cannabis in multiple sclerosis, known as the British CAMS study (Cannabinoids in Multiple Sclerosis), were published. The results of the 15-week-trial with eligible 630 patients had been published in November 2003 in the Lancet. 80 percent of the original study population participated in a 12 months follow-up study.

While in the short-term study there was no significant effect of cannabinoids on objective spasticity scores according to the Ashworth scale, the long-term study showed significant effects on this parameter in the THC group. As in the short-term study there was no significant objective improvement of spasticity in the cannabis group compared to placebo.

In the 15-week-study 657 patients with stable MS and muscle spasticity received either a capsulated cannabis extract, THC or a placebo. They received a maximum daily dose of 10-25 mg THC. 630 patients were eligible for statistical analysis. Although there was no objective evidence that cannabis relieved spasticity, or muscle stiffness, caused by the disease, patients reported subjective improvements in pain and spasticity. Mobility was improved as well. Study results caused different conclusions by experts with regard to the therapeutic benefits of cannabinoids in multiple sclerosis.

Until now only preliminary information on the 12-months-study is available. It is unclear why THC and not cannabis had effects on the Ashworth scale. Authors concluded from their data: "Initial results suggest that there may be more benefit over the longer-term than we found over the first part of the study."

(Sources: Press release of Cannabinoids in Multiple Sclerosis Trial of 9 October 2004; Zajicek J. The cannabinoids in MS study - final results from 12 months follow-up. Mult.Scler 2004; 10 (suppl 2): 115.)

News in brief

USA — Missouri

A survey by the University of Missouri indicates that there may be growing support for legalizing cannabis for medical use. A majority of 720 Missourians questioned in a telephone survey agreed that medical marijuana should be available for patients if it is prescribed by a doctor. 79 percent of the participants in this survey also believe that cannabis is addictive. "We were surprised to realize that people apparently see marijuana the same way they see legitimate pharmaceutical drugs that carry a high potential for abuse - opiates, cocaine, amphetamines, barbiturates, etc.," said Dr. Gary Brinker, one of the professors who conducted the survey. (Source: Associated Press of 30 December 2004)

Science — Inflammation of the brain

Basic research with brain cells shows that cannabinoids inhibit the generation of inflammatory mediators. A number of inflammatory mediators plays a role in brain damage, among them nitric oxide (a free radical), cytokines, and chemokines. Researchers investigated the effect of a synthetic cannabinoid on the production of several key inflammatory mediators by astrocytes. Astrocytes are type of glia cells, that fill the space between the nerve cells of the brain. The cannabinoid which works similar to THC inhibited the production of nitric oxide and of several chemokines (CXCL10, CCL2 and CCL5). Researchers concluded that "comparable agents may have therapeutic potential for the management of brain inflammation." (Source: Sheng WS, et al. Glia 2005;49(2):211-9)