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IACM-Bulletin of August 19, 2018


🏷️ Science/Human — Medical cannabis laws in the USA are associated with improved workplace safety

In a large study scientists demonstrated that the legalisation of the medical use of cannabis, improved workplace safety for workers aged 25 to 44. Investigators at the Department of Agricultural Economics and Economics of Montana State University in Bozeman, USA, analysed data of all 50 US states and the District of Columbia for the period 1992 to 2015.

Authors wrote: “Legalizing medical marijuana was associated with a 19.5% reduction in the expected number of workplace fatalities among workers aged 25-44 (…). The association between legalizing medical marijuana and workplace fatalities among workers aged 16-24, although negative, was not statistically significant at conventional levels. The association between legalizing medical marijuana and workplace fatalities among workers aged 25-44 grew stronger over time. Five years after coming into effect, MMLs [medical marijuana laws] were associated with a 33.7% reduction in the expected number of workplace fatalities.”

Anderson DM, Rees DI, Tekin E. Medical marijuana laws and workplace fatalities in the United States. Int J Drug Policy. 2018;60:33-39.

🏷️ Science/Human — The risk of dependence formation among heavy cannabis users in the USA declined in the past 15 years

The risk of dependence formation among heavy cannabis users appears to have declined between 2002 and 2016. This is the main result of a study published in the journal Drug and Alcohol Dependence by researchers of RAND Pardee Graduate School in Santa Monica, USA. They used data assembled from the National Survey on Drug Use and Health (2002-2016). Rates of self-reported dependence and constituent symptoms were calculated for heavy cannabis users.

Dependence among heavy cannabis users fell by 39%. Among dependence symptoms, most showed significant declines: reducing important activities; use despite emotional, mental, or physical problems; failing attempts to cutback; lots of time getting, using, or getting over marijuana; and failing to keep limits set on use. Reported tolerance showed no significant change. Authors concluded: “though it is unclear why, the risk of dependence formation among heavy marijuana users appear to have declined since 2002.”

Davenport S. Falling rates of marijuana dependence among heavy users. Drug Alcohol Depend. 2018;191:52-55.

🏷️ Science/Human — Patients with insomnia experience improved sleep by the use of cannabis

The use of cannabis flowers in 409 people with a specified condition of insomnia resulted in significant improvements of their sleep. The extent of therapeutic effects depended on the cannabis strain. These are the results of research conducted at the Department of Psychology of the University of New Mexico in Albuquerque, USA. Patients completed 1056 medical cannabis administration sessions during which they rated self-perceived insomnia severity levels prior to and following consumption.

Participants showed an average symptom severity reduction of -4.5 points on a 0 to 10 point visual analogue scale. Use of pipes and vaporizers was associated with greater symptom relief and more positive side effects as compared to the use of cannabis cigarettes, while vaporization was also associated with lower negative effects. CBD was associated with greater statistically significant symptom relief than THC. Flowers from cannabis sativa plants were associated with more negative side effects than flowers from cannabis indica or hybrid plant subtypes.

Vigil JM, Stith SS, Diviant JP, Brockelman F, Keeling K, Hall B. Effectiveness of Raw, Natural Medical Cannabis Flower for Treating Insomnia under Naturalistic Conditions. Medicines (Basel). 2018;5(3).

🏷️ Science/Human — Large study with CBD in patients with epilepsy demonstrates good long-term safety of the medication

In an open study with 72 children and 60 adults with different forms of treatment-resistant epilepsy adverse events decreased over time. Scientists of the Department of Neurology at the University of Alabama in Birmingham, USA, wrote that their prospective, open-level safety study of CBD in treatment resistant epilepsy “provides evidence for significant improvements in AEP [adverse events profile], CSSS [Chalfont Seizure Severity Scale], and SF [seizure frequency] at 12 weeks that are sustained over the 48-week duration of treatment.”

Patients started with a dose of at 5 mg/kg/day and titrated it up to a maximum dosage of 50 mg/kg/day. Data were analysed for the enrolment and visits at 12, 24, and 48 weeks. For all participants adverse events decreased between start of the study and the 12-week visit with stable scores thereafter. Seizure frequency within 2 weeks decreased from a mean of 144.4 at entry to 52.2 at 12 weeks and remained stable thereafter.

Szaflarski JP, Bebin EM, Cutter G, DeWolfe J, Dure LS, Gaston TE, Kankirawatana P, Liu Y, Singh R, Standaert DG, Thomas AE, Ver Hoef LW; UAB CBD Program. Cannabidiol improves frequency and severity of seizures and reduces adverse events in an open-label add-on prospective study. Epilepsy Behav. 2018 Aug 9. [in press]

News in brief

🏷️ Science/Human — Israeli pain clinicians view cannabis as an effective treatment for chronic pain

According to a survey of 79 registered active pain specialists in Israel, who had experience “in prescribing cannabis over prolonged periods view it as an effective and relatively safe treatment for chronic pain, based on their own experience.” Authors noted that their “responses suggest a possible change of paradigm from using cannabis as the last resort.” Almost all pain specialists prescribed cannabis. Among them, 63% find cannabis moderately to highly effective, 56% have encountered mild or no side effects, and only 5% perceive it as significantly harmful.

Institute of Pain Medicine, Tel Aviv Sourasky Medical Center, Israel.

Sharon H, et al. J Pain Res. 2018;11:1411-1419.

🏷️ Science/Human — Cannabinoids may be helpful in glioblastoma

Among natural products, which may have antitumor effects in glioblastoma (GBM), an aggressive brain tumour, are cannabinoids, terpenes and curcumin, because according to the authors “many have been shown to have a significant effect in decreasing the progress of GBM through known mechanisms.”

Faculty of Sciences, Universidad Austral de Chile, Valdivia, Chile.

Erices JI, et al. Phytother Res. 2018 Aug 15. [in press].

🏷️ Science/Human — CBD effective in children with epilepsy

Researchers reviewed the experience with the first 40 children enrolled in the New South Wales (Australia) Compassionate Access Scheme for children with treatment-resistant epilepsy. Authors wrote that the “caregivers of 12 children felt the overall health of their children had much or very much improved; clinicians assessed seven children as being much or very much improved.”

Sydney Children's Hospitals Network, Australia.

Chen KA, et al. Med J Aust. 2018 Aug 13. [in press]

🏷️ Science/Human — Results of a survey among Australian patients, who treat themselves with cannabis

Most of 1748 participants in a survey conducted in Australia were men (68.1%) and employed (56.6%), with a mean age of 37.9 years and mean reported period of medical cannabis use of 9.8 years. The most frequent reasons for medical cannabis use were anxiety (50.7%), back pain (50.0%), depression (49.3%), and sleep problems (43.5%).

University of Sydney, Australia.

Lintzeris N, et al. Med J Aust. 2018 Aug 13. [in press]

🏷️ Science/Animal — The use of CBD in dogs with arthritis was effective and safe

In a placebo-controlled study with 22 dogs suffering from osteoarthritis CBD in a dose of 2 mg/kg twice daily increased comfort and activity of the animals. No side-effects were reported by owners. Each treatment lasted for 4 weeks with a 2-week washout period.

College of Veterinary Medicine, Cornell University, Ithaca, USA.

Gamble LJ, et al. Front Vet Sci. 2018;5:165.

🏷️ Science/Animal — No negative effect of THC on male reproductive process

In a study with male mice, which received 10 mg THC per kg body weight daily for a period of 30 days, there was no evidence for negative effects on reproduction compared to a control group, including no influence on the weight of the testes, the sperm motility or the sperm concentration. Authors concluded that their “work contradicts the belief that THC consumption has a negative effect on male reproductive processes.”

Department of Animal Reproduction, INIA, Madrid, Spain.

López-Cardona AP, et al. Biochem Pharmacol. 2018 Aug 3. [in press]

🏷️ Science/Animal — Cannabidiol and cannabidivarin may be helpful in muscular dystrophy

In muscle cells from patients with Duchenne muscular dystrophy some cannabinoids (CBD, CBDV) promoted the formation of myotubes, developing skeletal muscle fibers. In a mouse model of muscular dystrophy these cannabinoids prevented the loss of locomotor activity. Authors wrote that their research may lead to the prevention of muscle degeneration in patients with Duchenne muscular dystrophy.

Endocannabinoid Research Group, National Research Council, Pozzuoli, Italy.

Iannotti FA, et al. Br J Pharmacol. 2018 Aug 3. [in press]

🏷️ Science/Animal — The endocannabinoid system involved in maintenance of homeostasis in the bowel

The influx of certain white blood cells (neutrophils) into the intestinal lumen is associated with severe damage to the mucosa in inflammatory bowel disease. Activation of the CB2 receptor is involved in inhibiting this influx and maintaining homeostasis in the healthy intestine.

University of Massachusetts Medical School, Worcester, USA.

Szabady RL, et al. J Clin Invest. 2018 Aug 13. [in press]

🏷️ Science/Animal — Endocannabinoids may improve memory despite exposure to alcohol

According to a study with rats increase of endocannabinoid levels by a blockade of FAAH (fatty acid amide hydrolase) may be associated with improved memory despite ethanol exposure.

University Hospital of Malaga, Spain.

Rivera P, et al. Biochem Pharmacol. 2018 Aug 8. [in press]

🏷️ Science/Animal — A disturbed function of the CB1 receptor exacerbates Alzheimer-like symptoms in mice

According to animal research dysfunction of the CB1 receptor “could account for the acceleration of the memory impairment observed.” Authors wrote that their research “suggests a crucial role for the CB1 receptor” and the progression of Alzheimer disease-related pathological events.

University of Barcelona-IDIBELL, Hospital of Llobregat, Spain.

Aso E, et al. Biochem Pharmacol. 2018 Aug 7. [in press]

🏷️ Science/Animal — Blockade of the CB2 receptor reduces kidney fibrosis

In animal models of kidney fibrosis a synthetic substance (XL-001), which binds to the CB2 receptor and behaves as an inverse agonist ameliorated kidney fibrosis and inflammation. Authors wrote that this novel inverse agonist “may provide a strategy in the fight against fibrotic kidney diseases.”

National Clinical Research Center of Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.

Zhou L, et al. Kidney Int. 2018 Aug 6. [in press]