Tag Archives: Addiction

Cannabinoid CB1 receptors control conditioned drug seeking.

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Abstract

“Recent developments have implicated cannabinoid CB1 receptors as a novel target for a new class of therapeutic agents used to treat drug addiction. CB1 receptors are expressed in the motivational circuitry of the brain and modulate drug seeking. Blockade of the CB1 receptor is particularly effective in reducing cue-induced reinstatement of drug seeking, an animal analogue of cue-induced relapse in human addicts. These relapse-preventing properties are observed with different classes of abused drug (i.e. psychostimulants, opiates, nicotine and alcohol). In addition, recent evidence indicates a more general role of CB1 receptors in reward-related memories, which is consistent with the proposed role of endocannabinoids in memory-related plasticity. Relapse-preventing actions and inhibitory effects on weight gain were confirmed recently in clinical trials with the CB1 antagonist rimonabant. Collectively, these clinical and preclinical studies suggest that antagonists of CB1 receptors offer a novel approach in the treatment of addictive behaviours.”

http://www.ncbi.nlm.nih.gov/pubmed/15992935

Endocannabinoid regulation of relapse mechanisms.

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Abstract

“Addiction involves a complex neuropharmacologic behavioural cycle, in which positive reinforcement exerted by the drug and the negative state of withdrawal drive the user to extremes to obtain the drug. Comprehensive studies have established that relapse is the most common outcome of recovery programs treating addictive behaviours. Several types of anticraving medication are available nowadays, such as naltrexone for the treatment of alcoholism, bupropion for nicotine, methadone or buprenorphine for heroin. This review focuses on recent behavioural data providing a rationale for an endocannabinoid mechanism underlying reinstatement of compulsive drug seeking. Studies supporting the contention that reinstatement of extinguished drug self-administration behaviour may be generated by cannabinoid CB1 receptor agonists and attenuated, if not blocked, by CB1 receptor antagonists, are here reviewed. In support to these findings, conditioned place preference studies substantiate the involvement of the endocannabinoid system in recidivism mechanisms by demonstrating that motivation to relapse can be triggered by CB1 receptor activation while blockade of such receptors may prevent reinstatement of place conditioning induced by either drug primings or drug-associated cues. Finally, biochemical studies evaluating changes in endocannabinoid levels, CB1 receptor density and CB1 mRNA expression during re-exposure to drug following extinction are also examined. Taken together, the evidence available has important implications in the understanding and treatment of relapsing episodes in patients undergoing detoxification.”

http://www.ncbi.nlm.nih.gov/pubmed/17936008

Cannabis as an adjunct to or substitute for opiates in the treatment of chronic pain.

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Abstract

“There is a growing body of evidence to support the use of medical cannabis as an adjunct to or substitute for prescription opiates in the treatment of chronic pain. When used in conjunction with opiates, cannabinoids lead to a greater cumulative relief of pain, resulting in a reduction in the use of opiates (and associated side-effects) by patients in a clinical setting. Additionally, cannabinoids can prevent the development of tolerance to and withdrawal from opiates, and can even rekindle opiate analgesia after a prior dosage has become ineffective. Novel research suggests that cannabis may be useful in the treatment of problematic substance use. These findings suggest that increasing safe access to medical cannabis may reduce the personal and social harms associated with addiction, particularly in relation to the growing problematic use of pharmaceutical opiates. Despite a lack of regulatory oversight by federal governments in North America, community-based medical cannabis dispensaries have proven successful at supplying patients with a safe source of cannabis within an environment conducive to healing, and may be reducing the problematic use of pharmaceutical opiates and other potentially harmful substances in their communities.”

http://www.ncbi.nlm.nih.gov/pubmed/22880540

Targeted modulators of the endogenous cannabinoid system: future medications to treat addiction disorders and obesity.

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Abstract

“The endogenous endocannabinoid system encompasses a family of natural signaling lipids (“endocannabinoids”) functionally related to (9)-tetrahydrocannabinol, the psychoactive ingredient of marijuana (cannabis), along with proteins that modulate the endocannabinoids, including enzymes, transporters, and receptors. The endocannabinoid system’s ubiquitous regulatory actions in health and disease underscore its importance to mammalian (patho)physiology and suggest discrete targets through which it may be modulated for therapeutic gain. Medications based on the endocannabinoid system are an important focus of contemporary translational research, particularly with respect to substance abuse and obesity, two prevalent disorders with a pathogenic component of endocannabinoid system hyperactivity. Pressing health care needs have made the rational design of targeted CB1 cannabinoid-receptor modulators a promising route to future medications with significant therapeutic impact against psychobehavioral and metabolic disturbances having a reward-supported appetitive component.”

http://www.ncbi.nlm.nih.gov/pubmed/17915075