Category Archives: Addiction

Interactions between cannabinoid receptor agonists and mu opioid receptor agonists in rhesus monkeys discriminating fentanyl.

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“Cannabinoid receptor agonists such as delta-9-tetrahydrocannabinol (Δ9-THC) enhance some (antinociceptive) but not other (positive reinforcing) effects of mu opioid receptor agonists, suggesting that cannabinoids might be combined with opioids to treat pain without increasing, and possibly decreasing, abuse.

These data indicate that the discriminative stimulus effects of nalbuphine are more sensitive to attenuation by cannabinoids than those of fentanyl. That the discriminative stimulus effects of some opioids are more susceptible to modification by drugs from other classes has implications for developing maximally effective therapeutic drug mixtures with reduced abuse liability.”

http://www.ncbi.nlm.nih.gov/pubmed/27184925

ENDOCANNABINOID SYSTEM: A multi-facet therapeutic target.

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“Cannabis sativa is also popularly known as marijuana. It is being cultivated and used by man for recreational and medicinal purposes from many centuries.

Study of cannabinoids was at bay for very long time and its therapeutic value could not be adequately harnessed due to its legal status as proscribed drug in most of the countries.

The research of drugs acting on endocannabinoid system has seen many ups and down in recent past. Presently, it is known that endocannabinoids has role in pathology of many disorders and they also serve “protective role” in many medical conditions.

Several diseases like emesis, pain, inflammation, multiple sclerosis, anorexia, epilepsy, glaucoma, schizophrenia, cardiovascular disorders, cancer, obesity, metabolic syndrome related diseases, Parkinson’s disease, Huntington’s disease, Alzheimer’s disease and Tourette’s syndrome could possibly be treated by drugs modulating endocannabinoid system.

Presently, cannabinoid receptor agonists like nabilone and dronabinol are used for reducing the chemotherapy induced vomiting. Sativex (cannabidiol and THC combination) is approved in the UK, Spain and New Zealand to treat spasticity due to multiple sclerosis. In US it is under investigation for cancer pain, another drug Epidiolex (cannabidiol) is also under investigation in US for childhood seizures. Rimonabant, CB1 receptor antagonist appeared as a promising anti-obesity drug during clinical trials but it also exhibited remarkable psychiatric side effect profile. Due to which the US Food and Drug Administration did not approve Rimonabant in US. It sale was also suspended across the EU in 2008.

Recent discontinuation of clinical trial related to FAAH inhibitor due to occurrence of serious adverse events in the participating subjects could be discouraging for the research fraternity. Despite of some mishaps in clinical trials related to drugs acting on endocannabinoid system, still lot of research is being carried out to explore and establish the therapeutic targets for both cannabinoid receptor agonists and antagonists.

One challenge is to develop drugs that target only cannabinoid receptors in a particular tissue and another is to invent drugs that acts selectively on cannabinoid receptors located outside the blood brain barrier. Besides this, development of the suitable dosage forms with maximum efficacy and minimum adverse effects is also warranted.

Another angle to be introspected for therapeutic abilities of this group of drugs is non-CB1 and non-CB2 receptor targets for cannabinoids.

In order to successfully exploit the therapeutic potential of endocannabinoid system, it is imperative to further characterize the endocannabinoid system in terms of identification of the exact cellular location of cannabinoid receptors and their role as “protective” and “disease inducing substance”, time-dependent changes in the expression of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/27086601

Beyond the CB1 Receptor: Is Cannabidiol the Answer for Disorders of Motivation?

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“The Cannabis sativa plant has been used to treat various physiological and psychiatric conditions for millennia.

Current research is focused on isolating potentially therapeutic chemical constituents from the plant for use in the treatment of many central nervous system disorders.

Of particular interest is the primary nonpsychoactive constituent cannabidiol (CBD).

Unlike Δ9-tetrahydrocannabinol (THC), CBD does not act through the cannabinoid type 1 (CB1) receptor but has many other receptor targets that may play a role in psychiatric disorders.

Here we review preclinical and clinical data outlining the therapeutic efficacy of CBD for the treatment of motivational disorders such as drug addiction, anxiety, and depression.

Across studies, findings suggest promising treatment effects and potentially overlapping mechanisms of action for CBD in these disorders and indicate the need for further systematic investigation of the viability of CBD as a psychiatric pharmacotherapy.”

http://www.ncbi.nlm.nih.gov/pubmed/27023732

Medical cannabis associated with decreased opiate medication use in retrospective cross-sectional survey of chronic pain patients.

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“Opioids are commonly used to treat patients with chronic pain (CP), though there is little evidence that they are effective for long term CP treatment.

Previous studies reported strong associations between passage of medical cannabis laws and decrease in opioid overdose statewide.

Our aim was to examine whether using medical cannabis for CP changed individual patterns of opioid use.

Using an online questionnaire, we conducted a cross-sectional retrospective survey of 244 medical cannabis patients with CP who patronized a medical cannabis dispensary in Michigan between November 2013 and February 2015. Data collected included demographic information, changes in opioid use, quality of life, medication classes used, and medication side effects before and after initiation of cannabis usage.

Among study participants, medical cannabis use was associated with a 64% decrease in opioid use (n=118), decreased number and side effects of medications, and an improved quality of life (45%).

This study suggests that many CP patients are essentially substituting medical cannabis for opioids and other medications for CP treatment, and finding the benefit and side effect profile of cannabis to be greater than these other classes of medications.

This article suggests that using medical cannabis for CP treatment may benefit for some CP patients. The reported improvement in quality of life, better side effect profile, and decreased opioid use should be confirmed by rigorous, longitudinal studies that also assess how CP patients use medical cannabis for pain management.”

http://www.ncbi.nlm.nih.gov/pubmed/27001005

Effects of fixed or self-titrated dosages of Sativex on cannabis withdrawal and cravings.

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“There is currently no pharmacological treatment approved for cannabis dependence. In this proof of concept study, we assessed the feasibility/effects of fixed and self-titrated dosages of Sativex (1:1, Δ9-tetrahydrocannabinol (THC)/cannabidiol (CBD)) on craving and withdrawal from cannabis among nine community-recruited cannabis-dependent subjects.

The results found in this proof of concept study warrant further systematic exploration of Sativex as a treatment option for cannabis withdrawal and dependence.”

http://www.ncbi.nlm.nih.gov/pubmed/26925704

Blockade of Nicotine and Cannabinoid Reinforcement and Relapse by a Cannabinoid CB1-Receptor Neutral Antagonist AM4113 and Inverse Agonist Rimonabant in Squirrel Monkeys.

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“Nicotine, the main psychoactive component of tobacco, and (-)-Δ9-tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, play major roles in tobacco and marijuana dependence as reinforcers of drug-seeking and drug-taking behavior.

Drugs that act as inverse agonists of cannabinoid CB1 receptors in the brain can attenuate the rewarding and abuse-related effects of nicotine and THC…

Recently-developed CB1-receptor neutral antagonists may provide an alternative therapeutic approach to nicotine and cannabinoid dependence.

These findings point to CB1-receptor neutral antagonists as a new class of medications for treatment of both tobacco dependence and cannabis dependence.”

http://www.ncbi.nlm.nih.gov/pubmed/26888056

Involvement of Endocannabinoids in Alcohol “Binge” Drinking: Studies of Mice with Human Fatty Acid Amide Hydrolase Genetic Variation and After CB1 Receptor Antagonists.

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“The endocannabinoid system has been found to play an important role in modulating alcohol intake.

Inhibition or genetic deletion of fatty acid amide hydrolase (FAAH; a key catabolic enzyme for endocannabinoids) leads to increased alcohol consumption and preference in rodent models.

A common human single-nucleotide polymorphism (SNP; C385A, rs324420) in the FAAH gene is associated with decreased enzymatic activity of FAAH, resulting in increased anandamide levels in both humans and FAAH C385A knock-in mice.

These data suggest that there is direct and selective involvement of the human FAAH C385A SNP and CB1 receptors in alcohol “binge” drinking.”

http://www.ncbi.nlm.nih.gov/pubmed/26857901

Attenuation of cue-induced reinstatement of nicotine seeking by URB597 through cannabinoid CB1 receptor in rats.

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“The endocannabinoid system is composed of endocannabinoids (such as anandamide), their target receptors (CB1 and CB2 receptors, CB1Rs and CB2Rs), the enzymes that degrade them (fatty-acid-amide-hydrolase (FAAH) for anandamide), and an endocannabinoid transporter. FAAH inhibition has been recently identified as having a critical involvement in behaviors related to nicotine addiction and has been shown to reduce the effect of nicotine on the mesolimbic dopaminergic system via CB1R and peroxisome proliferator-activated receptor alpha (PPARα). Thus, inhibition of FAAH may represent a novel strategy for smoking cessation, but its mechanism of action on relapse to nicotine seeking is still unknown.

OBJECTIVE:

The study aims to explore the mechanism of action of the inhibitor of FAAH activity, URB597, on relapse to nicotine seeking by evaluating the effect of the CB1R, CB2R, and PPARα antagonists on the attenuating effect of URB597 on cue-induced reinstatement of nicotine seeking in rats.

RESULTS:

URB597 reduced cue-induced reinstatement of nicotine seeking, an effect that was reversed by the CB1R antagonist rimonabant, but not by the CB2R or PPARα antagonists AM630 and MK886, respectively.

CONCLUSIONS:

These results indicate that URB597 reduces cue-induced reinstatement in rats through a CB1 receptor-dependent mechanism, and not via CB2R or PPARα. Since FAAH inhibition represent a novel and promising strategy for tobacco smoking cessation, dissecting how it produces its action may lead to a better understanding of the neurobiological mechanisms underlying nicotine addiction.”

http://www.ncbi.nlm.nih.gov/pubmed/26864774

Cannabidiol Oil for Decreasing Addictive Use of Marijuana: A Case Report.

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“This case study illustrates the use of cannabidiol (CBD) oil to decrease the addictive use of marijuana and provide anxiolytic and sleep benefits.

The second most abundant component-CBD-has been suggested to have the medicinal effects of decreasing anxiety, improving sleep, and other neuro-protective effects.

The mechanism of action for CBD has been suggested to be antagonistic to the psychoactive properties of THC in many locations within the central nervous system. Such action raises the issue of whether it might be beneficial to use CBD in isolation to facilitate withdrawal of marijuana use.

With use of the CBD oil, the patient reported being less anxious, as well as settling into a regular pattern of sleep. He also indicated that he had not used any marijuana since starting the CBD oil. With the decrease in the dosage to 18 mg, the patient was able to maintain his nonuse of marijuana.”

http://www.ncbi.nlm.nih.gov/pubmed/26807069

Medical marijuana programs – Why might they matter for public health and why should we better understand their impacts?

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“Although cannabis is an illegal drug, ‘medical marijuana programs’ (MMPs) have proliferated (e.g., in Canada and several US states), allowing for legal cannabis use for therapeutic purposes.

While both health risks and potential therapeutic  for cannabis use have been documented, potential public health impacts of MMPs – also vis-à-vis other psychoactive substance use – remain under-explored.

We briefly reviewed the emerging evidence on MMP participants’ health status, and specifically other psychoactive substance use behaviors and outcomes.

MMP participants report improvements in overall health status, and specifically reductions in levels of risky alcohol, prescription drug and – to some extent – tobacco or other illicit drug use…”

http://www.ncbi.nlm.nih.gov/pubmed/26844050