IACM-Bulletin of September 28, 2003

IACM — News at the 2nd IACM Conference on Cannabinoids in Medicine (II)

Here are some more study results presented at the IACM Cologne Conference on 12-13 September at the Medical School of the University of Cologne. Erroneously the poster abstracts by Dr. Rudolf Brenneisen et al., Dr. Zlatko Mehmedic et al., and Dr. Miriam Schneider and Dr. Michael Koch had not been included in the first reader. Please find online the updated reader with both lecture and poster abstracts on the IACM web site (www.cannabis-med.org).

* Cannabis reduces postoperative pain

Dr. Anita Holdcroft of Imperial College in London investigated the effects of a capsulated cannabis extract in post-operative pain in 57 patients with doses of 5, 10 and 15 mg THC. Relief of pain and adverse effects were dose related. Dr. Holdcroft recently started a multi-centre study with 400 patients to test a cannabis extract with 10 mg THC. (Lecture by Anita Holdcroft)

* Cannabis alleviates symptoms in cancer patients

In an open study at the Lukas Clinic in Arlesheim, Switzerland, the effects of a capsulated cannabis extract were tested in 40 palliative cancer patients. Under the guidance of Dr. Silke Helwig the study intended to find out the maximally tolerated dose (MTD) to be used in a future controlled study. Based on side effects the MTD was concluded to be 0.15 mg THC/kg body weight. 24 patients noted an increase of appetite, 20 relief of pain, and 9 relief of nausea. (Lecture by Martin Schnelle)

* Endocannabinoids reduce size of myocardial infarction

In an animal study researchers of Cardiff and Cambridge University, UK, found out that the endocannabinoid anandamide limits myocardial infarction. One possible mechanism of action is via interaction with either cannabinoid-1 or cannabinoid-2 receptors, but other mechanisms of action may be involved. (Lecture by Willam Ford)

* Cannabis improves night vision

Inspired by reports of Jamaican and Moroccan fishermen Dr. Ethan Russo of Missoula, USA, and colleagues of Spain and Marocco investigated the effects of THC (dronabinol) and cannabis on night vision. The study examined the results of double-blinded placebo controlled THC administration in doses between 2.5 and 20 mg in one subject and in three subjects before and after smoking cannabis. In both test situations, improvements in night vision were noted after THC or cannabis. It is believed that this effect is dose-dependent and mediated by cannabinoid receptors in the retina. (Lecture by Ethan Russo)

* Alleviation of neuropathic pain with CT-3

Dr. Udo Schneider and colleagues of the Medical School of Hanover tested the efficacy of CT-3, a synthetic cannabinoid, in 21 patients with chronic neuropathic pain. Pain was significantly reduced without relevant side effects. (Lecture by Udo Schneider)

(Source: Reader of the IACM 2nd Conference on Cannabinoids in Medicine,

www.cannabis-med.org)

Science — THC and cannabis alleviate pain in multiple sclerosis

At the Fourth Congress of the European Federation of IASP Chapters on 2-6 September 2003 in Prague two new clinical studies on cannabis products in multiple sclerosis were presented, one by Danish researchers who investigated the effects of THC (dronabinol) in 24 MS patients and one by British researchers who studied the efficacy of a sublingual cannabis spray in 66 MS patients.

Under the guidance of Dr. KB Svendsen of the Danish Pain Research Center of the Aarhus University Hospital, 24 MS patients with neuropathic pain underwent a double blind placebo controlled crossover trial with dronabinol (THC), which was titrated up to a maximum of 10 mg daily. The two three week treatment phases were separated by a three weeks wash out period. Spontaneous pain intensity decreased significantly during dronabinol treatment compared with placebo. Pain relief was significantly higher during dronabinol.

Drs. CA Young and DJ Rog of the Walton Centre for Neurology and Neurosurgery in Liverpool presented results of their placebo controlled parallel study with a sublingual cannabis spray containing 2.7 mg THC and 2.5 mg CBD per spray, of which they could take up to 48 units a day, in 66 MS patients. After four weeks there was a significant mean reduction in pain for cannabis and a significant reduction in sleep disturbance.

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

(Source: Poster abstracts of the Prague Congress)

Science — THC and cannabis reduce neuropathic pain in damage of the brachial plexus

THC and a cannabis extract with a mix of THC and CBD reduced the pain in 48 patients due to damage of the brachial plexus and improved sleep quality. The study was a randomised double-blind crossover trial consisting of three 2-week periods.

Patients continued on all previous stable medications including analgesics. During each 2-week period, subjects received in random order either placebo, THC (18,25 on average) or a mix of THC and CBD (cannabidiol) with a ratio of 1:1. THC and cannabis were applied as a sublingual spray.

Both the THC and THC:CBD extracts decreased pain and improved sleep. The effects were moderate although mostly statistically significant. Researchers concluded , that “given the refractory nature of the pain in this patient group, this study shows that cannabis-based medicinal extracts represent a significant advance in treatment.”

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

(Source: Berman J, et al. Efficacy of two cannabis-based medicinal extracts for relief of central neuropathic pain from brachial plexus avulsion: results of a randomised controlled trial. Anaesthesia, 2003;58:938)

Switzerland — Parliament blocks decriminalisation of cannabis

Ignoring the appeals of its health minister, the National Council (Swiss Lower House of Parliament) on 25 September blocked government moves to decriminalize cannabis. After an emotional debate, the National Council voted 96-89 to take no action on the government's proposed narcotics law revision. This means the legislation will be kicked back to the Council of States (Upper House of Parliament) which overwhelmingly approved it in December 2001.

The government argued that police resources were too stretched to enforce restrictive and outdated laws, with an estimated 500,000 people out of a population of 7 million being occasional or regular soft drug users. "Bans on cannabis and alcohol have always proved a failure," Health Minister Pascal Couchepin said in an impassioned speech to parliament. He said the proposed legislation aimed to step up preventive measures and cut down on black market profits.

In practice, cannabis users rarely face police sanctions as Switzerland is more relaxed about drugs than many other countries. However, there are big local variations and - given the legal grey area - police often alternate between tolerance and repression.

The upper house will reconsider the legislation in one of its forthcoming sessions. It can either amend it or send it back unchanged to the lower house. Supporters of a more liberal drug policy hope that the package will finally win parliamentary passage once the pressures of the general election have eased.

(Sources: Associated Press of 25 September 2003, Tagesanzeiger of 25 September 2003)

News in brief

Germany — Berlin

Possession of up to 15 grams of cannabis may soon become legal in the state of Berlin. The move is supported by the Greens, the Free Democrats, the Social Democrats and the Socialists and opposed by the Christian Democrats. The decision is intended to be made in some months after discussion in the responsible committees of the state parliament. (Source: Berliner Zeitung of 25 September 2003)

Canada — Government marijuana

Some of the first patients to smoke government marijuana say it is "disgusting" and they want their money back. Health Canada, the federal health department, started selling marijuana in July following a court order that patients should not be forced to get their marijuana from drug dealers on the streets. No patients have complained directly to Health Canada so far, spokeswoman Krista Apse said, and the department will not accept returns or provide refunds. (Source: Associated Press of 15 September 2003)

Science — Vomiting

In an animal study THC and CBD (cannabidiol) reduced vomiting. Shrews were

injected with one of the two cannabinoids 10 min prior to an injection with lithium, which causes vomiting. THC produced a dose-dependent suppression of lithium-induced vomiting, with higher doses producing greater suppression than lower doses. CBD produced a biphasic effect with lower doses producing suppression and higher doses producing enhancement of vomiting. (Source: Parker LA, et al. Psychopharmacology (Berl) 2003 Sep 10 [electronic publication ahead of print])

Science — Pain

In animal tests there was an additive analgesic effect of a topical opiate and a cannabinoid. Topical application of morphine and a synthetic cannabinoid (WIN 55, 212-2) yielded significantly greater analgesic effects than that of topical morphine alone. Additionally, spinally administered ineffective doses of the cannabinoid potentiated the antinociceptive effects of topical morphine. (Source: Yesilyurt O, et al. Pain 2003 Sep;105(1-2):303-8.)

Science — Pain

In an animal study with rats the number of cannabinoid-1 receptors increased following nerve injury. This increased the efficacy of cannabinoids in neuropathic pain. Researchers conclude that the “upregularion” of CB1 receptors “may contribute to the therapeutic effects of exogenous cannabinoids on neuropathic pain.” (Source: Lim G, et al. Pain. 2003 Sep;105(1-2):275-283.)

Science — Pain

The analgesic effects of THC alone and in combination with morphine were tested in healthy subjects. Pain was caused by different means. THC did not significantly reduce pain. In the cold and heat tests it even produced increased pain. A slight additive analgesic effect could be observed for THC-morphine in the electrical stimulation test. (Source: Naef M, et al. Pain 2003 Sep;105(1-2):79-88)