IACM-Bulletin of August 7, 2005

Science — Patients with inflammatory bowel disease may benefit from cannabinoids

Patients with inflammatory bowel disease may benefit from cannabis-based drugs, UK scientists believe. The Bath University team found an abundant number of cannabinoid-2 receptors in certain tissues of the intestine of patients. They believe this is part of the body's attempt to dampen down the inflammation and that giving a drug that binds to these receptors could boost this.

Dr. Karen Wright and colleagues examined gut samples from healthy people and patients with inflammatory bowel disease. CB1 and CB2 receptors were found in several tissues of the large intestine of both groups. However, the patients had far greater numbers of CB2 receptors in the epithelium characteristic for the disease. Activation of the CB2 receptors by cannabinoids enhanced healing of the tissue. This observation provides a rationale for the treatment of inflammatory bowel diseases such as Crohn's disease and ulcerative colitis with cannabis products.

When people have inflammatory bowel disease their immune system produces inflammation in different areas of the digestive tract. This causes symptoms such as pain and urgent diarrhoea. Anecdotally, people with Crohn's disease and ulcerative colitis have reported that their symptoms get better when they use cannabis. First clinical trials with cannabis extracts in Crohn's disease are under way by the University of Munich (with Cannador) and by the British firm GW Pharmaceuticals (with Sativex).

(Sources: BBC News of 31 July 2005; Wright K, Rooney N, Feeney M, Tate J, Robertson D, Welham M, Ward S. Differential expression of cannabinoid receptors in the human colon: cannabinoids promote epithelial wound healing. Gastroenterology 2005;129(2):437-53)

Canada/USA — Canadian police raided the headquarters of the British Columbia Marijuana Party

Canadian police acting under orders from officials of the United States raided the headquarters of the British Columbia Marijuana Party (BCMP) in Vancouver on 22 July and arrested its leader Marc Emery. Emery and two others are accused by the U.S. of conspiracy to manufacture cannabis, conspiracy to distribute cannabis seeds to the USA and conspiracy to engage in money laundering. The U.S. is seeking their extradition.

On 2 August Justice Patrick Dohm allowed Emery to go free on $50,000 bail. He said Emery can continue his political work for the Marijuana Party. Emery will also be allowed to continue running his bookstore, where he sold cannabis seeds, and can resume operations at his Cannabis Culture magazine.

His lawyer John Conroy said the case against Emery is unfair because Canadian police have never charged him while he openly sold seeds for nine years. "Even Health Canada was directing people to online websites like Mr. Emery's to buy seeds. And now they're helping the Americans," he said at a news conference.

(Sources: Canadian Press of 2 August 2005, Cannabis Culture of 29 July 2005)

News in brief

Spain — Clinical studies with Sativex

Starting this autumn about 600 patients will be enrolled in clinical studies to treat different diseases with the cannabis extract Sativex. The patients who suffer from cancer, neurological disorders or AIDS will be included in the studies by six Catalan hospitals who participate in this program. It is intended to include 65 patients with neuropathic pain due to multiple sclerosis, 65 patients with spasticity due to MS, 130 patients with other neurological disorders, 40 patients with AIDS who suffer from appetite loss, and 60 cancer patients undergoing chemotherapy. If the treatment of chemotherapy-induced nausea and vomiting proves to be effective it is intended to treat another 240 patients with Sativex, which will be imported from Canada. (Source: El País of 28 July 2005)

Argentina — Health minister supports medical use

Health Minister Ginés González García said that he supports the medical use of cannabis but that he is against the legalization of drugs. He pointed out that morphine is also used to treat pain. (Source: Inforegion of 24 July 2005)

Science — Schizophrenia

Israelian scientists propose that the association between cannabis use and increased risk for schizophrenia that have been observed in recent studies from Sweden, the Netherlands, New Zealand, and Israel may not be causal. Several studies have reported an association between genes encoding the cannabinoid receptor and schizophrenia. The researchers write: "An alternative explanation of the association between cannabis use and schizophrenia might be that pathology of the cannabinoid system in schizophrenia patients is associated with both increased rates of cannabis use and increased risk for schizophrenia, without cannabis being a causal factor for schizophrenia." (Source: Weiser M, Noy S. Dialogues Clin Neurosci. 2005;7(1):81-5.)

Science — Cannabis use and cancer risk

Scientists of the International Agency for Research on Cancer (IARC), an institution of the World Health Organisation (WHO) reviewed the epidemiological data on cannabis use and cancer. Two cohort studies and 14 case-control studies were reviewed. The results were conflicting and most studies did not find a clear association between cannabis use and cancer. However, scientists noted that "sufficient studies are not available to adequately evaluate marijuana impact on cancer risk. Several limitations of previous studies include possible underreporting where marijuana use is illegal, small sample sizes, and too few heavy marijuana users in the study sample." (Source: Hashibe M, et al. Alcohol 2005;35(3):265-75.)