Category Archives: Addiction

The endocannabinoid-alcohol crosstalk: recent advances on a bi-faceted target.

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“Increasing evidence focuses on the endocannabinoid system as a relevant player in the induction of aberrant synaptic plasticity and related addictive phenotype following chronic excessive alcohol drinking.

Besides, the endocannabinoid system is implicated in the pathogenesis of alcoholic liver disease.

Interestingly, whereas the involvement of CB1 cannabinoid receptors in alcohol rewarding properties is established, the central and peripheral action of CB2 cannabinoid signalling is still to be elucidated.

This review aims at giving the input to deepen knowledge on the role of the endocannabinoid system, highlighting the advancing evidence that suggests that CB1 and CB2 receptors may play opposite roles in the regulation of both the reinforcing properties of alcohol in the brain and the mechanisms responsible for cell injury and inflammation in the hepatic tissue.

The manipulation of the endocannabinoid system could represent a bi-faceted strategy to counteract alcohol-related dysfunction in central transmission and liver structural and functional disarrangement.”

https://www.ncbi.nlm.nih.gov/pubmed/29770478

https://onlinelibrary.wiley.com/doi/abs/10.1111/1440-1681.12967

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Review of the neurological benefits of phytocannabinoids.

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“Numerous physical, psychological, and emotional benefits have been attributed to marijuana since its first reported use in 2,600 BC in a Chinese pharmacopoeia. The phytocannabinoids, cannabidiol (CBD), and delta-9-tetrahydrocannabinol (Δ9-THC) are the most studied extracts from cannabis sativa subspecies hemp and marijuana. CBD and Δ9-THC interact uniquely with the endocannabinoid system (ECS). Through direct and indirect actions, intrinsic endocannabinoids and plant-based phytocannabinoids modulate and influence a variety of physiological systems influenced by the ECS.

METHODS:

In 1980, Cunha et al. reported anticonvulsant benefits in 7/8 subjects with medically uncontrolled epilepsy using marijuana extracts in a phase I clinical trial. Since then neurological applications have been the major focus of renewed research using medical marijuana and phytocannabinoid extracts.

RESULTS:

Recent neurological uses include adjunctive treatment for malignant brain tumors, Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, neuropathic pain, and the childhood seizure disorders Lennox-Gastaut and Dravet syndromes. In addition, psychiatric and mood disorders, such as schizophrenia, anxiety, depression, addiction, postconcussion syndrome, and posttraumatic stress disorders are being studied using phytocannabinoids.

CONCLUSIONS:

In this review we will provide animal and human research data on the current clinical neurological uses for CBD individually and in combination with Δ9-THC. We will emphasize the neuroprotective, antiinflammatory, and immunomodulatory benefits of phytocannabinoids and their applications in various clinical syndromes.”

https://www.ncbi.nlm.nih.gov/pubmed/29770251

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5938896/

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Deficient endocannabinoid signaling in the central amygdala contributes to alcohol dependence-related anxiety-like behavior and excessive alcohol intake.

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“Negative emotional states that are associated with excessive alcohol intake, particularly anxiety-like states, have been linked to opponent processes in the central nucleus of the amygdala (CeA), affecting stress-related transmitters and monoamines.

This study extends these observations to include endocannabinoid signaling in alcohol-dependent animals.

Rats and mice were exposed to chronic intermittent alcohol with vapor inhalation or liquid diet to induce dependence. In vivo microdialysis was used to estimate interstitial concentrations of endocannabinoids [N-arachidonoylethanolamine (anandamide; AEA) and 2-arachidonoylglycerol (2-AG)] and amino acids (glutamate and GABA) in rat CeA. Additionally, we evaluated the inhibition of endocannabinoids clearance enzymes [monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase] on anxiety-like behavior and alcohol consumption in alcohol-dependent rats and mice.

Results revealed that alcohol dependence produced decreases in baseline 2-AG dialysate levels and increases in baseline levels of glutamate and GABA. Acute alcohol abstinence induced an enhancement of these dependence-induced effects and the levels of 2-AG and GABA were restored upon alcohol re-exposure. Additional studies showed that the increased CeA 2-AG levels induced by restraint stress and alcohol self-administration were blunted in alcohol-dependent rats. Pharmacological studies in rats and mice showed that anxiety-like behavior and alcohol consumption were increased in alcohol-dependent animals, and these behavioral effects were attenuated mainly by MAGL inhibitors [MJN110 (10 and 20 mg/kg) in rats and JZL184 (1 and 3 mg/kg) in mice].

The present results suggest a key role for endocannabinoid signaling in motivational neuroadaptations during alcohol dependence, in which a deficiency in CeA 2-AG signaling in alcohol-dependent animals is linked to stress and excessive alcohol consumption.”

https://www.ncbi.nlm.nih.gov/pubmed/29748627

https://www.nature.com/articles/s41386-018-0055-3

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Effects of cannabinoid type 2 receptor agonist AM1241 on morphine-induced antinociception, acute and chronic tolerance, and dependence in mice.

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“Morphine is a potent opioid analgesic used to alleviate moderate or severe pain but the development of drug tolerance and dependence limits its use in pain management.

Previous studies showed that cannabinoid type 2 (CB2) receptor ligands may modulate opioid effects. However, there is no report of the effect of CB2 receptor agonist on acute morphine tolerance and physical dependence. We therefore investigated the effect of a CB2 receptor agonist (AM1241) on morphine-induced morphine tolerance and physical dependence in mice.

Our findings suggest that coadministration of the CB2 receptor agonist and morphine could increase morphine antinociception and reduce morphine tolerance and physical dependence in mice.

PERSPECTIVE:

Combination of a CB2 agonist and morphine may provide a new strategy for better treatment of acute and chronic pain, and prevention of opioid tolerance and dependence. This may also provide a clue for the treatment of opioid tolerance and dependence in clinic.”

https://www.ncbi.nlm.nih.gov/pubmed/29729431

https://www.sciencedirect.com/science/article/pii/S1526590018301597

“Antinociceptive Synergy between 9 -Tetrahydrocannabinol and Opioids after Oral Administration” http://jpet.aspetjournals.org/content/jpet/304/3/1010.full.pdf

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Cannabinoid-Opioid Interaction in Chronic Pain

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“Cannabis inhalation with a vaporizer may enhance the analgesia of opioids.

In addition, previous research suggest that Cannabis may be useful in attenuating the development of opioid tolerance and dependence.

This is the first human study to show that inhaled cannabis safely potentiates the analgesia of opioids.

HUMAN STUDY SHOWS INHALED CANNABIS POTENTIATES ANALGESIA OF OPIOIDS.”

https://www.naturalmedicinejournal.com/journal/2012-06/cannabinoid-opioid-interaction-chronic-pain

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Antinociceptive Synergy between 9 -Tetrahydrocannabinol and Opioids after Oral Administration

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“Cannabinoids and opioids have been shown to possess several similar pharmacological effects, including analgesia

The analgesic effects of opioids, such as morphine and codeine, in mice are enhanced by oral administration of the cannabinoid 9 -tetrahydrocannabinol (9 -THC).

These findings suggest that the use of a low-dose combination of analgesics is a valid and effective approach for the treatment of pain and necessitates further study.

In summary, we have observed that 9 -THC enhances the antinociceptive effects of morphine and codeine in a synergistic fashion. This is the first report of a true synergistic interaction between oral 9 -THC and morphine or codeine, since previous studies have only examined one-dose combinations.

Much more work needs to be done to elucidate the mechanisms by which cannabinoids and opioids interact to produce analgesia. However, the implication that a combination of drugs may be more effective than either drug alone, and at the same time possibly reduce the occurrence of side effects, should provoke further study on analgesic drug interactions.”

http://jpet.aspetjournals.org/content/jpet/304/3/1010.full.pdf

http://healthdocbox.com/Substance_Abuse/71109245-Antinociceptive-synergy-between-9-tetrahydrocannabinol-and-opioids-after-oral-administration.html

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Molecular and cellular basis of cannabinoid and opioid interactions.

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“Cannabinoids and opioids have been shown to possess several similar pharmacological effects, including analgesia and stimulation of brain circuitry that are believed to underlie drug addiction and reward. In recent years, these phenomena have supported the possible existence of functional links in the mechanisms of action of both types of drugs.

The present review addresses the recent advances in the study of biochemical and molecular mechanisms underlying opioid and cannabinoid interaction. Several hypothesis have been formulated to explain this cross-modulation including the release of opioid peptides by cannabinoids or endocannabinoids by opioids and interaction at the level of receptor and/or their signal transduction mechanisms.

Moreover it is important to consider that the nature of cannabinoid and opioid interaction might differ in the brain circuits mediating reward and in those mediating other pharmacological properties, such as antinociception.

Further studies are needed since a better knowledge of the opioid-cannabinoid interaction may lead to exciting therapeutic possibilities.”

https://www.ncbi.nlm.nih.gov/pubmed/15927245

https://www.sciencedirect.com/science/article/pii/S0091305705001450?via%3Dihub

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Cannabidiol reverses attentional bias to cigarette cues in a human experimental model of tobacco withdrawal.

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“Cannabidiol (CBD), a non-intoxicating cannabinoid, may be a promising novel smoking cessation treatment due to its anxiolytic properties, minimal side-effects and research showing it may modify drug cue salience.

We used an experimental medicine approach with dependent cigarette smokers to investigate if (1) overnight nicotine abstinence, compared with satiety, will produce greater attentional bias (AB), higher pleasantness ratings of cigarette-related stimuli and increased craving and withdrawal; (2) CBD in comparison to placebo, would attenuate AB, pleasantness of cigarette-related stimuli, craving and withdrawal and not produce any side-effects.

FINDINGS:

When participants received placebo, tobacco abstinence increased AB (p=.001, d =.789) compared with satiety. However, CBD reversed this effect, such that automatic AB was directed away from cigarette cues (p=.007, d= .704) and no longer differed from satiety (p=.82). Compared with placebo, CBD also reduced explicit pleasantness of cigarette images (p=.011; d=.514). Craving (Bayes Factor: 7.07) and withdrawal (Bayes Factor: 6.48) were unaffected by CBD, but greater in abstinence compared with satiety. Systolic blood pressure decreased under CBD during abstinence.

CONCLUSIONS:

A single 800mg oral dose of cannabidiol (CBD) reduced the salience and pleasantness of cigarette cues, compared with placebo, after overnight cigarette abstinence in dependent smokers. CBD did not influence tobacco craving or withdrawal or any subjectively rated side-effects.”

https://www.ncbi.nlm.nih.gov/pubmed/29714034

https://onlinelibrary.wiley.com/doi/abs/10.1111/add.14243

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The effect of high-dose dronabinol (oral THC) maintenance on cannabis self-administration.

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“There is a clear need for advancing the treatment of cannabis use disorders. Prior research has demonstrated that dronabinol (oral THC) can dose-dependently suppress cannabis withdrawal and reduce the acute effects of smoked cannabis.

The present study was conducted to evaluate whether high-dose dronabinol could reduce cannabis self-administration among daily users.

CONCLUSIONS:

Chronic dronabinol dosing can reduce cannabis self-administration in daily cannabis users and suppress withdrawal symptoms. Cannabinoid agonist medications should continue to be explored for therapeutic utility in the treatment of cannabis use disorders.”

https://www.ncbi.nlm.nih.gov/pubmed/29689485

https://www.drugandalcoholdependence.com/article/S0376-8716(18)30184-4/fulltext

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Testing associations between cannabis use and subcortical volumes in two large population-based samples.

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“Disentangling the putative impact of cannabis on brain morphology from other comorbid substance use is critical. After controlling for the effects of nicotine, alcohol and multi-substance use, this study aimed to determine whether frequent cannabis use is associated with significantly smaller subcortical grey matter volumes.

FINDINGS:

After correcting for multiple testing (p=0.007), cannabis use was unrelated to any subcortical ROI. However, maximum nicotine use was associated with significantly smaller thalamus volumes in middle-age males.

CONCLUSIONS:

In exploratory analyses based on young adult and middle age samples, normal variation in cannabis use is statistically unrelated to individual differences in brain morphology as measured by subcortical volume.”

https://www.ncbi.nlm.nih.gov/pubmed/29691937

https://onlinelibrary.wiley.com/doi/abs/10.1111/add.14252

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