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IACM-Bulletin of December 2, 2012

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Science/Human — Cannabis effective in epilepsy according to two case reports

Two patients with epilepsy were able to control their seizures by the use of cannabis, scientists from the Epilepsy Center at the Department of Neurology of the University of California in San Francisco, USA, reported in the journal Epilepsy & Behavior. Both stopped cannabis use upon admission to the epilepsy monitoring unit of the Department and developed a dramatic increase in seizure frequency documented by video-EEG telemetry. With this technique patients can be continuously monitored and recorded with a video camera and an EEG (electroencephalograph).

Both patients suffered from focal epilepsy. This means that the source of the seizures within the brain is localized and not generalized. In a 43-year-old patient seizure frequency increased from one to two in one night with cannabis to ten seizures after stopping cannabis use. The second subject, a 60-year-old patient experienced five seizures in a 12-hour period after ceasing cannabis use. Both patients did not respond to conventional anti-epileptic medication. Researchers concluded that their epilepsy “was nearly controlled through regular outpatient marijuana use.”

Hegde M, Santos-Sanchez C, Hess CP, Kabir AA, Garcia PA. Seizure exacerbation in two patients with focal epilepsy following marijuana cessation. Epilepsy Behav 2012;25(4):563-566.

Science/Human — Tetrahydrocannabivarin (THCV) may offer treatment against diabetes according to clinical study

According to a press release by GW Pharmaceuticals tetrahydrocannabivarin (THCV), which they call GWP42004, may offer promise in the treatment of type 2 diabetes. In a small clinical study, which examined a number of clinically relevant endpoints in patients with type 2 diabetes, the oral cannabinoid showed consistent evidence of anti-diabetic effects. This 5-arm study was a 13 week placebo controlled study of THCV (5mg), CBD (100mg) and two separate ratios (5mg:5mg and 100mg:5mg) of CBD:THCV. Each treatment was administered twice daily.

The exploratory study enrolled a total of 62 type 2 diabetes patients, such that each treatment group had 11-14 patients. THCV caused reduced fasting plasma glucose levels with an increase in fasting insulin, improved function of beta-cells in the pancreas, which produce insulin, and had other positive effects.

GW Pharmaceuticals of 28 November 2012

WHO Trial Registration Data Set

Science/Human — Mixed results of a cannabis extract in chronic pain caused by multiple sclerosis in clinical study

The cannabis extract Sativex produced mixed results in the treatment of neuropathic pain due to multiple sclerosis according to a study with 339 patients, researchers of the Pain and Anaesthesia Research Centre of St Bartholomew's Hospital in London, UK, reported. Sativex is a spray containing nearly equal amounts of CBD and THC. Patients received the medication in addition to their current medication, which failed to control their pain adequately. The trial consisted of two phases. In phase A 167 participants received Sativex and 172 received placebo in a double-blind manner for 14 weeks. In phase B 58 patients continued to receive either placebo or Sativex for 18 weeks to investigate maintenance of treatment effects.

In phase A 50 per cent of cannabis patients experienced pain reduction of more than 30 per cent compared to 45 per cent of placebo patients, which was not significantly different. However, during phase B Sativex was superior to placebo, with 57 per cent of patients receiving placebo failing treatment versus only 24 per cent of patients from the cannabis group. In addition, mean pain intensity and sleep quality improved in the cannabis group compared to placebo. Authors concluded that “the results of the current investigation were equivocal, with conflicting findings in the two phases of the study. (…) These findings suggest that further studies are required to explore the full potential of THC/CBD spray in these patients.”

Langford RM, Mares J, Novotna A, Vachova M, Novakova I, Notcutt W, Ratcliffe S. A double-blind, randomized, placebo-controlled, parallel-group study of THC/CBD oromucosal spray in combination with the existing treatment regimen, in the relief of central neuropathic pain in patients with multiple sclerosis. J Neurol. 2012 Nov 21. [in press]

News in brief

Holland — Government wants to classify THC rich cannabis similar to heroin

Strong strains of cannabis will be designated Class A drugs in the Netherlands, the same category as heroin and cocaine, a minister said. Justice Minister Ivo Opstelten told the Dutch Parliament under the plan coffee shops in the Netherlands will only be allowed to sell cannabis with a THC level of less than 15 per cent. Today, one strain of Bedrocan cannabis, which is available in Dutch pharmacies, contains more than 15 per cent THC.

UPI of 20 November 2012.

Canada — Two thirds support legalization or decriminalization of cannabis

In a representative opinion poll conducted by the Forum Poll among Canadians 18 years of age and older, two thirds (65 per cent) supported either legalization and taxation of cannabis (33 per cent) or decriminalization of small amounts (32 per cent).

Forum Research of 20 November 2012

Science/Animal — Cannabinoid receptors contribute to effects of electroacupuncture

Electroacupuncture produced pain-reducing and anti-inflammatory effects in rats, and these effects appeared to be mediated through CB1 and CB2 receptor activation.

Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil.

Gondim DV, et al. Can J Physiol Pharmacol 2012;90(11):1479-89.

Science/Human — THC changes perception of time

In a study with 44 subjects effects of THC, which was administered intravenously at doses from 0.015 to 0.05 mg per kg body weight, on estimation of time was investigated. While infrequent users showed overestimation of elapsed time at medium and high doses, frequent cannabis users were not affected due to tolerance.

Department of Psychiatry, Yale School of Medicine, Yale University, New Haven, USA.

Sewell RA, et al. Psychopharmacology (Berl). 2012 Nov 24. [in press]

Science/Animal — Severe stress changes CB1 receptors in the brain

In an experimental study rats were exposed to cats, which is very stressing for them. Seven days later there was still a reduction in CB1 receptor expression in brain areas (frontal cortex, amygdala) related to symptoms of post-traumatic stress disorder.

Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.

Campos AC, et al. Neurosci Lett. 2012 Nov 21. [in press]