Opioid addiction from the chronic use of prescription analgesics and illicit agents represents a major unmet public health crisis. Current pharmacotherapies for opioid dependence, such as opioid maintenance therapy (e.g., methadone and buprenorphine), reduce the need for illicit substances and alleviate opioid withdrawal, but possess a similar side effect profile as other opioids and can also trigger severe opioid withdrawal responses. Consequently, a strong need remains for the development of new treatment strategies that would relieve patients of opioid dependence without transferring this dependency to another drug. D9-tetrahydrocannabinol (THC), the primary psychoactive constituent in Cannabis sativa, has long been known to reduce naloxone- precipitated withdrawal symptoms in opioid-dependent animals. However, THC and other CB1 receptor agonists display several cannabimimetic side effects, including marijuana-like subjective activity, that limit their general therapeutic potential. Alternatively, increasing brain levels of the endogenous cannabinoids anandamide and 2-arachidonylglycerol (2-AG) though the blockade of their respective catabolic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) represents a promising therapeutic approach that lacks many of the undesirable side effects of direct-acting CB1 receptor agonists. We have recently developed JZL184, the first highly potent, selective, and orally active MAGL inhibitor. This compound causes significant elevations in brain 2-AG levels and robustly reduces the magnitude of naloxone-precipitated somatic withdrawal responses in morphine-dependent mice, but elicits far fewer cannabimimetic effects compared with THC. While FAAH inhibitors produce significant effects in preclinical models of pain and anxiety, our preliminary data show that these compounds lack efficacy in reducing opioid withdrawal effects. Thus, the overall objective of this proposal is to test whether optimized MAGL inhibitors will reduce the constellation of withdrawal symptoms in opioid-dependent mice and rhesus monkeys undergoing abstinence. In the proposed experiments, we will characterize the metabolism, pharmacokinetics, target selectivity, safety profile, and effectiveness of JZL184 and structurally related analogues in ameliorating withdrawal symptoms in established rodent and nonhuman primate models of opioid dependence. The following three major hypotheses will be tested: 1) MAGL inhibitors will reduce somatic and affective withdrawal signs in opioid- dependent rodents;2) MAGL inhibitors will reduce opioid withdrawal symptoms and withdrawal-related increases in heroin self-administration in opioid-dependent rhesus monkeys;and 3) inhibition of MAGL will produce minimal side effects compared to direct opioid and cannabinoid receptor agonists. The ultimate goal of this application is to identify a potent, selective, orally active, safe, and efficacious MAGL inhibitor that prevents opioid withdrawal in mouse and monkey preclinical models and is ready for IND-enabling toxicology en route to clinical development as a novel therapeutic for treating opioid abuse.

Public Health Relevance

Opioid addicts undergoing abstinence suffer from a constellation of physiological and behavioral withdrawal signs that cause great suffering and high-potential for relapse to drug usage;new targeted therapies are desperately needed to assist addicts in alleviating their dependence on opioid drugs while minimizing the potential for relapse. Here, we propose an innovative new way to treat opioid withdrawal with selective inhibitors of the endocannabinoid-degrading enzyme monoacylglycerol lipase (MAGL) and detail a plan to test this premise by developing best-in-class MAGL inhibitors with good translational potential for evaluation in animal models of opioid dependence and withdrawal. If successful, this research program could deliver next- generation therapies for opioid addiction that show excellent efficacy with limited potential for side effects and drug relapse.

National Institute of Health (NIH)
National Institute on Drug Abuse (NIDA)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZDA1-JXR-D (06))
Program Officer
Rapaka, Rao
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Scripps Research Institute
La Jolla
United States
Zip Code
Donvito, Giulia; Wilkerson, Jenny L; Damaj, M Imad et al. (2016) Palmitoylethanolamide Reverses Paclitaxel-Induced Allodynia in Mice. J Pharmacol Exp Ther 359:310-318
Grim, T W; Morales, A J; Gonek, M M et al. (2016) Stratification of Cannabinoid 1 Receptor (CB1R) Agonist Efficacy: Manipulation of CB1R Density through Use of Transgenic Mice Reveals Congruence between In Vivo and In Vitro Assays. J Pharmacol Exp Ther 359:329-339
Xu, Changqing; Hermes, Douglas J; Mackie, Ken et al. (2016) Cannabinoids Occlude the HIV-1 Tat-Induced Decrease in GABAergic Neurotransmission in Prefrontal Cortex Slices. J Neuroimmune Pharmacol 11:316-31
Wilkerson, J L; Ghosh, S; Bagdas, D et al. (2016) Diacylglycerol lipase β inhibition reverses nociceptive behaviour in mouse models of inflammatory and neuropathic pain. Br J Pharmacol 173:1678-92
Owens, Robert A; Ignatowska-Jankowska, Bogna; Mustafa, Mohammed et al. (2016) Discriminative Stimulus Properties of the Endocannabinoid Catabolic Enzyme Inhibitor SA-57 in Mice. J Pharmacol Exp Ther 358:306-14
Limebeer, Cheryl L; Rock, Erin M; Puvanenthirarajah, Nirushan et al. (2016) Elevation of 2-AG by monoacylglycerol lipase inhibition in the visceral insular cortex interferes with anticipatory nausea in a rat model. Behav Neurosci 130:261-6
Wilkerson, Jenny L; Niphakis, Micah J; Grim, Travis W et al. (2016) The Selective Monoacylglycerol Lipase Inhibitor MJN110 Produces Opioid-Sparing Effects in a Mouse Neuropathic Pain Model. J Pharmacol Exp Ther 357:145-56
Sticht, Martin A; Limebeer, Cheryl L; Rafla, Benjamin R et al. (2016) Endocannabinoid regulation of nausea is mediated by 2-arachidonoylglycerol (2-AG) in the rat visceral insular cortex. Neuropharmacology 102:92-102
Wiebelhaus, Jason M; Grim, Travis W; Owens, Robert A et al. (2015) Δ9-tetrahydrocannabinol and endocannabinoid degradative enzyme inhibitors attenuate intracranial self-stimulation in mice. J Pharmacol Exp Ther 352:195-207
Jackson, Kia J; Jackson, Asti; Carroll, F Ivy et al. (2015) Effects of orally-bioavailable short-acting kappa opioid receptor-selective antagonist LY2456302 on nicotine withdrawal in mice. Neuropharmacology 97:270-4

Showing the most recent 10 out of 27 publications