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IACM-Bulletin of August 26, 2012

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Science/Human — Long-term use of cannabis extract is associated with sustained effect on spasticity in MS patients

According to an open study in the UK with 146 patients with multiple sclerosis and spasticity the cannabis extract Sativex was still effective after one year of treatment. The study was headed by Dr Michael Serpell, professor of anaesthesia at the Pain Clinic in Gartnavel of the University of Glasgow. During a 6-week controlled trial, Sativex had a clinically relevant effect on spasticity. Mean treatment exposure of an open follow-up study was 334 days and patients administered on average 7.3 sprays (about 20 mg THC and 18 mg CBD) per day.

Fifty-two (36 per cent) patients withdrew from the study in the first year, 14 per cent due to side effects and 9 per cent due to lack of efficacy. Common (more than 10 per cent of cases) adverse effects were dizziness and fatigue. Serious adverse effects occurred in five patients, with two psychiatric events reported by one patient. Authors wrote: "No new safety concerns were identified with chronic Sativex treatment, and serious adverse effects were uncommon. There was no evidence of tolerance developing, and patients who remained in the study reported continued benefit."

Serpell MG, Notcutt W, Collin C. Sativex long-term use: an open-label trial in patients with spasticity due to multiple sclerosis. J Neurol. 2012 Aug 10. [in press]

USA — Citizens of Arkansas and Massachusetts will decide on laws on the legalization of cannabis for medicinal use in November

On 22 August officials of the State of Arkansas approved placing a proposal to legalize the medical use of cannabis on the November ballot. Supporters aim to make Arkansas the first southern state to approve the drug for some conditions. The government said Arkansans for Compassionate Care turned in enough signatures to put the law before the voters.

Seventeen states and the District of Columbia have legalized the medical use of cannabis in some form. The proposal would allow Arkansans with certain diseases to purchase cannabis from dispensaries with a doctor's recommendation. These conditions include cancer, glaucoma, HIV, AIDS and Alzheimer's disease. The proposal also would allow patients or a caregiver to grow cannabis if the patient lives more than five miles away from a dispensary. Voters in Massachusetts will also decide in November whether to legalize the medical use of cannabis. In addition, in Colorado, Oregon and Washington voters this fall will vote on decriminalisation of cannabis for recreational use.

San Francisco Chronicle of 22 August 2012

News in brief

Science/Human — Cannabis use not associated with development of depression

According to a long-term study in 45087 Swedish men no effects of cannabis use were observed on later development of depression, but an increased risk for schizophrenia was confirmed. Subjects provided data on cannabis use at the age of 18 and were followed for 35 years.

Karolinska Institutet, Stockholm, Sweden.

Manrique-Garcia E, et al. BMC Psychiatry, 2012;12(1):112.

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Science/Human — Cannabis decreased accident risk in coal miners

Coal miners involved in accidents presented with lower THC concentrations in their urine than miners not involved in accidents, while those involved in accidents presented with higher cocaine and opioid concentrations. The study compared 100 coal miners involved in accidents and 215 control subjects.

St. Mary's Occupational Medicine Clinic, Evansville, USA.

Price JW. J Addict Med. 2012 Aug 14. [in press]

Science/Animal — Activation of CB2 receptor protects the brain

Activation of the cannabinoid-2 receptor by a synthetic cannabinoid (0-1966) increased the integrity of the blood-brain barrier in mice after traumatic brain injury. Repeated treatments with the cannabinoid attenuated blood-brain barrier damage and degeneration of nerve cells of the brain.

Thomas Jefferson University Hospital, Philadelphia, USA.

Amenta PS, et al. J Neurosci Res. 2012 Aug 18. [in press]

Science/Cells — Anandamide shows potential to protect nerve cells against Alzheimer’s disease

In a study with nerve cells, anandamide enhanced the activity of a certain gene (Notch-1), which may restore the development of new nerve cells and cognition in Alzheimer’s disease.

University of Dublin/Trinity College Institute of Neuroscience, Ireland.

Tanveer R, et al. J Biol Chem. 2012 Aug 13. [in press]

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Science/Animal — Feeding of fish with linoleic acid increases endocannabinoid concentrations

Vegetable oils such as soybean oil are recognised as suitable alternatives to fish oil in feed for Atlantic salmon but introduce high amounts of linoleic acid, an omega-6 fatty acid, in the salmon fillet. Atlantic salmon were fed fish oil and soybean oil for 6 months. Feeding of fish with soybean oil increased linoleic acid, decreased long-chain omega-3 fatty acids and elevated the endocannabinoids 2-AG and anandamide, resulting in accelerated weight gain.

National Institute of Nutrition and Seafood Research, Bergen, Norway.

Alvheim AR, et al. Br J Nutr. 2012 Aug 10:1-10. [in press]

Science/Animal — CBD protected the kidneys from transient reduction of blood supply

Cannabidiol (CBD) given intravenously one hour before and 12 hours after reducing blood supply to the kidneys for 30 minutes in rats reduced damage to the organs. Researchers concluded that “Cannabidiol, via its antioxidant and anti-inflammatory properties, may represent a potential therapeutic option to protect” against damage to kidneys caused by temporarily reduced blood supply.

College of Medicine, King Faisal University, Al-Ahsa, Saudi Arabia.

Fouad AA, et al. Life Sci. 2012 Aug 1. [in press]