IACM-Bulletin of March 19, 2006

Science UK — Mixed results in study with Sativex in spasticity due to multiple sclerosis

On 17 March GW Pharmaceuticals reported disappointing results from a phase III trial with the cannabis extract Sativex with 335 people with spasticity due to MS. The company said multiple sclerosis patients who stuck to the trial’s protocols did benefit. But an analysis of all study participants - whether or not they complied to the protocol – found no statistically significant advantage compared with a placebo.

The results mean that GW may now delay filing for regulatory approval of Sativex in the UK. "We need to pause for breath from a regulatory perspective and decide whether to go full steam ahead with a filing for this indication or whether it makes more sense strategically for us to wait for results of the neuropathic pain studies before filing," Managing Director Justin Gover told Reuters.

All patients who had participated in the trial reported on 17 March were taking best available anti-spasticity medication and remained on such medication through the trial. Hence, any improvements seen in the trial were obtained over and above currently available treatment. The primary outcome measure was the improvement in spasticity as measured on a 0-10 numeric rating scale. The duration of treatment in the study was 14 weeks.

(Sources: Press release of GW Pharmaceuticals of 17 March 2006, Reuters of 17 March 2006)

Science — THC reduces nocturnal agitation in patients with Alzheimer's disease

Scientist of the Charité in Berlin presented a small study with positive effects of THC on nocturnal agitation in six patients with advanced dementia, among them five patients with Alzheimer's disease. Participants received 2.5 mg THC in the evening for two weeks. The drug resulted in an objective reduction of nocturnal motor activity, measured by a device fixed at one arm that registers number and intensity of movements. Nocturnal movements reduced to 59 per cent of baseline values on average.

In an accompanied assessment of neuropsychological symptoms by the investigators using a standardized questionnaire, the Neuropsychiatric Inventory (NPI), a positive influence of THC on motor behaviour, agitation, irritability, and appetite disturbances was observed. Side effects were not noted. The new study confirms investigations of 1997 and 2003, which showed reduction of agitation by THC in patients suffering from Alzheimer's disease.

Treatment of agitation is often insufficient by the available medicinal drugs such as neuroleptics. The authors of the current study note that THC may be a new treatment option for this group of patients and could help to prevent costly and long-term hospitalisation. A somewhat higher dosing may possibly have an even higher therapeutic efficacy.

(Source: Walther S, Mahlberg R, Eichmann U, Kunz D. Delta-9-tetrahydrocannabinol for nighttime agitation in severe dementia. Psychopharmacology (Berl) 7 March 2006; [electronic publication ahead of print])

Science — Moderate regular cannabis use does not deteriorate memory and attention

Researchers of the University of Utrecht in the Netherlands did not find any differences in the performance of moderate regular cannabis users, who were abstinent from the drug for one week, and non-users in tasks on working memory and selective attention. They also did not find differences in overall patterns of brain activity measured by functional magnetic resonance imaging (fMRI). However, a closer look at brain activity revealed a significant alteration in a small area of the left cortex.

The regular cannabis users had used between 675 and 5.400 cannabis cigarettes during their life and between 75 and 900 (median: 350) cannabis cigarettes in the past year. Non-users had used between 0 and 15 cannabis cigarettes during their life. In the working memory task participants had to memorize five consonants. Later consonants were presented and subjects had to press a button when a consonant appeared that belonged to the memorized list. The selective attention task required participants to detect tones with a higher or a lower pitch than a baseline tone, and similarly to detect dots with a larger or smaller size than the baseline dot.

Researchers concluded that they "did not find evidence for robust long-term deficits in working memory and selective attention in frequent but relatively moderate cannabis users after 1 week of abstinence." However, they noted that they "cannot completely rule out effects of cannabis on brain function," because of the difference in activity in one brain region that is involved in working memory. They wrote that most previous studies focussed on extremely heavy users who are not representative for the majority of recreational cannabis users.

(Source: Jager G, Kahn RS, Van Den Brink W, Van Ree JM, Ramsey NF. Long-term effects of frequent cannabis use on working memory and attention: an fMRI study. Psychopharmacology (Berl) 2006 Mar 7; [electronic publication ahead of print])

News in brief

Argentina — Medical use

For the first time the Argentine judiciary considered the possession of cannabis for personal use as justified if it was for therapeutic purposes. The court of appeals has revoked the conviction of a woman accused for the possession of cannabis by a lower court, because it did not take the reason for the use of the drug into account. María Romilda Servini de Cubría said that she used cannabis to alleviate her pain resulting from a spinal cord disease and to improve her sleep. (Source: El Pais of 13 March 2006)

Germany — Study on criminal prosecution

According to a study by the Max Planck Institute for Foreign and International Criminal Law, there are significant differences between various German states with respect to how they prosecute offences against the Federal Narcotics Law. The investigation commissioned by the Federal Health Ministry shows that "in Bavaria, up to 60% of the criminal proceedings related to cannabis use are closed without a sentence, compared to up to 90% in Schleswig-Holstein and Berlin. In light of the requirements set by the Federal Supreme Court, these differences are not unproblematic.” In 1994 the Court had requested that lawmakers ensure a largely uniform judicial practice. (Source: Press release by the Max Planck Institute of 9 March 2006)

USA — Poll on legalization

According to a poll by Zogby International 46 per cent of citizens of the USA support an amendment of the federal law "to let states legally regulate and tax marijuana the way they do liquor and gambling." 49 per cent of respondents opposed this amendment of the law and five per cent were undecided. Zogby interviewed 1,004 adults. (Source: NORML of 16 March 2006)

Science — Arthritis

In cell studies with cartilage cells British researchers investigated the effects of two synthetic cannabinoids on degradation of cartilage constituents that was induced by Interleukin-1-alpha. Interleukin-1 is a protein involved in inflammation. The cannabinoids protected the cartilage matrix from degradation, an effect that was possibly mediated by cannabinoid receptors. (Source: Mbvundula EC, et al. J Pharm Pharmacol 2006;58(3):351-8)

USA — Steve Kubby

Steve Kubby, an activist for medical cannabis from California, who was forced to return to the United States earlier this year has been freed from jail after serving a third of his four-month jail sentence, officials said. He was released after 40 days for good behaviour and because of a need to reduce crowding. He fled to Canada following his 2001 conviction for possession of hallucinogens. (Source: Associated Press of 7 March 2006)