The abuse potential of the synthetic cannabinoid nabilone

Clinical Benefits and Safety of Medical Cannabis Products: A Narrative Review on Natural Extracts

Interest in medical cannabis and cannabis-based medicinal products (CBMPs) has increased greatly in recent years. Two cannabinoids are of principal importance; delta-9-tetrahydrocannabinol (∆9-THC), the primary psychoactive component, and also cannabidiol (CBD), considered non-intoxicating. Each has distinct mechanisms of action and different therapeutic potentials. CBMPs differ in their ∆9-THC and CBD components; predominantly ∆9-THC, balanced formulations with equivalent ∆9-THC and CBD elements, and CBD-predominant products. In this narrative review, we evaluate the published evidence for the clinical benefits of CBMPs and overall benefits in well-being. We also review the overall safety profile and discuss the potential for dependence with CBMPs. Evidence can be drawn from a wide range of randomized and other controlled studies and from observational real-world studies. Most data from observational registry studies are supportive of ∆9-THC-based products (∆9-THC-predominant or balanced CBMPs) in the management of chronic neuropathic pain. Balanced products are also effective in reducing spasticity in multiple sclerosis. Most CBMPs show benefit in providing symptomatic benefits in reducing anxiety, nausea, and in improving sleep, but the place of specific products is more subtle, and choice guided by specific circumstances. Symptomatic improvements are accompanied by improved quality of life and well-being. Safety data indicate that CBMPs are generally well tolerated in most patients without specific contraindications. The majority of adverse effects are non-serious, and transient; most are principally associated with ∆9-THC and are dose-dependent. In contrast to recreational cannabis use, there is little evidence from clinical studies that CBMPs have any potential for dependence.

Advice to People with Parkinson's in My Clinic: Cannabis

Cannabis (in all the varied methods of delivery) continues to garner significant attention as a potential therapeutic intervention for neurodegenerative disorders, including Parkinson's disease (PD). The recent legalization of personal use of cannabis products in some parts of the world has increased this interest and with it, potential availability to many more people. However, such access has led to more questions than answers for both patients and health care professionals. These include what symptom(s) of PD will cannabis products treat; what dose; what type of cannabis product to use and what are the side effects?

Eye Tracking in Patients with Parkinson’s Disease Treated with Nabilone–Results of a Phase II, Placebo-Controlled, Double-Blind, Parallel-Group Pilot Study

The topic of the therapeutic use of cannabinoids in Parkinson’s disease (PD) is broadly discussed and frequently comes up in the outpatient clinic. So far, there are only a few randomized clinical trials assessing the effects of cannabinoids in PD. We are able to demonstrate a reduction in non-motor symptom (NMS) burden after the administration of nabilone. As impairment of attention and working memory have been described earlier as possible side effects, we assess cognitive performance using saccadic paradigms measured by an eye tracker. We do not observe a significant difference in any of the saccadic paradigms between PD patients on placebo versus those treated with nabilone. We, therefore, conclude that top-down inhibitory control is not affected by the tetrahydrocannabinol analogue. Nabilone did not significantly worsen cognitive performance and appears to be safe to use in selected PD patients who suffer from disabling NMS.

Consensus-based recommendations for titrating cannabinoids and tapering opioids for chronic pain control

AIMS

Opioid misuse and overuse have contributed to a widespread overdose crisis and many patients and physicians are considering medical cannabis to support opioid tapering and chronic pain control. Using a five-step modified Delphi process, we aimed to develop consensus-based recommendations on: 1) when and how to safely initiate and titrate cannabinoids in the presence of opioids, 2) when and how to safely taper opioids in the presence of cannabinoids and 3) how to monitor patients and evaluate outcomes when treating with opioids and cannabinoids.

RESULTS

In patients with chronic pain taking opioids not reaching treatment goals, there was consensus that cannabinoids may be considered for patients experiencing or displaying opioid-related complications, despite psychological or physical interventions. There was consensus observed to initiate with a cannabidiol (CBD)-predominant oral extract in the daytime and consider adding tetrahydrocannabinol (THC). When adding THC, start with 0.5-3 mg, and increase by 1-2 mg once or twice weekly up to 30-40 mg/day. Initiate opioid tapering when the patient reports a minor/major improvement in function, seeks less as-needed medication to control pain and/or the cannabis dose has been optimised. The opioid tapering schedule may be 5%-10% of the morphine equivalent dose (MED) every 1 to 4 weeks. Clinical success could be defined by an improvement in function/quality of life, a ≥30% reduction in pain intensity, a ≥25% reduction in opioid dose, a reduction in opioid dose to <90 mg MED and/or reduction in opioid-related adverse events.

CONCLUSIONS

This five-stage modified Delphi process led to the development of consensus-based recommendations surrounding the safe introduction and titration of cannabinoids in concert with tapering opioids.

Evidence for the Endocannabinoid System as a Therapeutic Target in the Treatment of Cannabis Use Disorder

Purpose of Review

Cannabis use disorder (CUD) is highly prevalent. Psychotherapy alone is not adequately effective, with few individuals achieving abstinence. Pharmacotherapeutic supplementation may improve efficacy, and the endocannabinoid system presents a target specifically dysregulated by heavy cannabis use. This review compiles current literature evaluating endocannabinoid modulation as a treatment strategy for CUD, with implications for future research.

Recent Findings

Cannabinoid receptor agonists have been found to reduce cannabis withdrawal symptoms without a notable effect on relapse, and antagonists can produce severe psychiatric symptoms. Fatty acid amide hydrolase inhibitors and cannabidiol demonstrate the most promising efficacy in treating CUD thus far, but research with these compounds is still preliminary.

Summary

Components of the endocannabinoid system may serve as unique treatment targets with differential efficacy for the treatment of cannabis use disorder as a whole. Further research is needed exploring novel methods for targeting endocannabinoid dysfunction in CUD.

Safety Considerations in Cannabinoid-Based Medicine

Cannabinoids are a diverse class of chemical compounds that are increasingly recognized as potential therapeutic options for a range of conditions. While many studies and reviews of cannabinoids focus on efficacy, safety is much less well reported. Overall assessment of the safety of cannabinoid-based medicines is confounded by confusion with recreational cannabis use as well as different study designs, indications, dosing, and administration methods. However, clinical studies in registered products are increasingly available, and this article aims to discuss and clarify what is known regarding the safety profiles of cannabinoid-based medicines, focusing on the medical and clinical safety evidence and identifying areas for future research. The two most well-studied cannabinoids are Δ9-tetrahydrocannabinol (THC), or its synthetic variants (dronabinol, nabilone), and cannabidiol (CBD). Across diverse indications, dizziness and fatigue are generally the most common adverse events experienced by patients receiving THC or combined THC and CBD. Patients receiving THC may experience adverse cognitive effects and impairment in psychomotor skills, with implications for driving and some occupations, while CBD may help to lower the psychotropic effects of THC when used in combination. Studies on dependency and addiction in a medical context are limited, but have shown inconsistent findings regarding misuse potential. Generally, the recommended route of administration is oral ingestion, as smoking medicinal cannabinoid products potentially releases mutagenic and carcinogenic by-products. There are several potential drug-drug interactions and contraindications for cannabinoid-based medicines, which physicians should account for when making prescribing decisions. The available evidence shows that, as with any other class of pharmaceuticals, cannabinoid-based medicines are associated with safety risks which should be assessed in the context of potential therapeutic benefits. Each patient should be assessed on an individual basis and physicians must rely on informed, evidence-based decision-making when determining whether a cannabinoid-based medicine could be an appropriate treatment option.

Therapeutic potential and safety considerations for the clinical use of synthetic cannabinoids

The phytocannabinoid Δ9-tetrahydrocannabinol (THC) was isolated and synthesized in the 1960s. Since then, two synthetic cannabinoids (SCBs) targeting the cannabinoid 1 (CB1R) and 2 (CB2R) receptors were approved for medical use based on clinical safety and efficacy data: dronabinol (synthetic THC) and nabilone (synthetic THC analog). To probe the function of the endocannabinoid system further, hundreds of investigational compounds were developed; in particular, agonists with (1) greater CB1/2R affinity relative to THC and (2) full CB1/2R agonist activity. This pharmacological profile may pose greater risks for misuse and adverse effects relative to THC, and these SCBs proliferated in retail markets as legal alternatives to cannabis (e.g., novel psychoactive substances [NPS], "Spice," "K2"). These SCBs were largely outlawed in the U.S., but blanket policies that placed all SCB chemicals into restrictive control categories impeded research progress into novel mechanisms for SCB therapeutic development. There is a concerted effort to develop new, therapeutically useful SCBs that target novel pharmacological mechanisms. This review highlights the potential therapeutic efficacy and safety considerations for unique SCBs, including CB1R partial and full agonists, peripherally-restricted CB1R agonists, selective CB2R agonists, selective CB1R antagonists/inverse agonists, CB1R allosteric modulators, endocannabinoid-degrading enzyme inhibitors, and cannabidiol. We propose promising directions for SCB research that may optimize therapeutic efficacy and diminish potential for adverse events, for example, peripherally-restricted CB1R antagonists/inverse agonists and biased CB1/2R agonists. Together, these strategies could lead to the discovery of new, therapeutically useful SCBs with reduced negative public health impact.

Use of a synthetic cannabinoid (nabilone) in the ongoing management of posttraumatic stress disorder nightmares in the Canadian Armed Forces: Results of an anonymous online survey

Introduction: The synthetic cannabinoid nabilone has shown promise in the management of posttraumatic stress disorder (PTSD) nightmares. To date, three clinical papers have been published showing positive results in nightmare suppression in civilian and military populations. This medication came on the market as an antiemetic. Nabilone has been used on an off-label basis at the Canadian Forces Operational Trauma and Stress Support Centre (OTSSC) in Ottawa for over a decade for PTSD nightmares. To date, there are no published reports of the ongoing experiences of patients who have been prescribed this medication for nightmare suppression. This research was conducted with the intent to fill this gap in the literature. Methods: An anonymous online survey was conducted in order to obtain a better understanding of the clinical effects experienced by those who continued taking nabilone. Eligible participants were active military members diagnosed with PTSD who were prescribed nabilone for the suppression of chronic nightmares. Results: Sixty military members responded to questions related to their ongoing experience using nabilone. Prior to taking nabilone, they had suffered from PTSD nightmares for an average of seven years. Suppression of nightmares was reported by 73% of respondents who continued taking nabilone. A small proportion self-discontinued nabilone to determine whether the medication was still needed. Of those who discontinued, most reported a return of nightmares an average of 1 week later; however, not all experienced a recurrence of nightmares. These findings support attempting a reduction or cessation at some point during treatment. For those who continued to experience nightmares, suppression was achieved with similar dosages to those previously prescribed; this suggests that nightmares are chronic and may need a longer duration of treatment. Discussion: This is the first survey to capture data for nabilone as a PTSD nightmare treatment beyond seven weeks. The results of this survey conform to the existing literature showing the efficacy of nabilone, a synthetic cannabinoid, as having a positive effect on nightmare suppression.

Cannabis, Cannabinoids, and Brain Morphology: A Review of the Evidence

Cannabis and cannabinoid-based products are increasingly being accepted and commodified globally. Yet there is currently limited understanding of the effect of the varied cannabinoid compounds on the brain. Exogenous cannabinoids interact with the endogenous cannabinoid system that underpins vital functions in the brain and body, and they are thought to perturb key brain and cognitive function. However, much neuroimaging research has been confined to observational studies of cannabis users, without examining the specific role of the various cannabinoids (Δ⁹-tetrahydrocannabinol, cannabidiol, etc.). This review summarizes the brain structural imaging evidence to date associated with cannabis use, its major cannabinoids (e.g., Δ⁹-tetrahydrocannabinol, cannabidiol), and synthetic cannabinoid products that have emerged as recreational drugs. In doing so, we seek to highlight some of the key issues to consider in understanding cannabinoid-related brain effects, emphasizing the dual neurotoxic and neuroprotective role of cannabinoids, and the need to consider the distinct role of the varied cannabinoids in establishing their effect on the brain.

Medication overuse headache: an overview of clinical aspects, mechanisms, and treatments

INTRODUCTION

Medication-overuse headache (MOH) is a common debilitating neurological disorder, with a prevalence of 1% to 7% in general population. It affects more than 60 million people worldwide and provokes substantial burden. Despite that, most practitioners don't know MOH. This review aims at presenting MOH clinical features, pathophysiology insights, and recent knowledge and guidance regarding treatments.

AREAS COVERED

A literature search in the major medical databases including the terms 'medication overuse headache,' 'chronic daily headache,' 'chronic migraine,' 'symptomatic medication overuse' and others, published between 1990 and 2020, was carried out.

EXPERT COMMENTARY

Primary headache sufferers such as migraineurs and tension-type headache patients may increase the headache frequency and induce the transition from episodic to chronic forms, as well as develop MOH, in the presence of medication overuse. There is evidence of structural and functional changes in some areas of the brain, which may identify those likely to respond or not to treatments. Despite the geographical differences and lack of consensus regarding approaches, to educate the patients about reducing medication intake, to withdraw overused medications and to start prophylaxis in some sufferers are crucial steps. Emerging treatments as monoclonal antibodies to migraine may result in better adherence and tolerability profiles as well as outcomes.

Role of cannabis in inflammatory bowel diseases

For many centuries, cannabis (marijuana) has been used for both recreational and medicinal purposes. Currently, there are about 192 million cannabis users worldwide, constituting approximately 3.9% of the global population. Cannabis comprises more than 70 aromatic hydrocarbon compounds known as cannabinoids. Endogenous circulating cannabinoids, or endocannabinoids, such as anandamide and 2-arachidonoyl-glycerol, their metabolizing enzymes (fatty acid amide hydrolase and monoacylglycerol lipase) and 2 G-protein coupled cannabinoid receptors, CB1 and CB2, together represent the endocannabinoid system and are present throughout the human body. In the gastrointestinal (GI) tract, the activated endocannabinoid system reduces gut motility, intestinal secretion and epithelial permeability, and induces inflammatory leukocyte recruitment and immune modulation through the cannabinoid receptors present in the enteric nervous and immune systems. Because of the effects of cannabinoids on the GI tract, attempts have been made to investigate their medicinal properties, particularly for GI disorders such as pancreatitis, hepatitis, and inflammatory bowel diseases (IBD). The effects of cannabis on IBD have been elucidated in several small observational and placebo-controlled studies, but with varied results. The small sample size and short follow-up duration in these studies make it difficult to show the clear benefits of cannabis in IBD. However, cannabis is now being considered as a potential drug for inflammatory GI conditions, particularly IBD, because of its spreading legalization in the United States and other countries and the growing trend in its use. More high-quality controlled studies are warranted to elucidate the mechanism and benefits of cannabis use as a possible option in IBD management.

Persistence of use of prescribed cannabinoid medicines in Manitoba, Canada: a population-based cohort study

BACKGROUND AND AIMS

To estimate prevalence of continuous use (persistence) of prescribed cannabinoid medications for up to 1 year from initial prescription in Manitoba, Canada and predictors of duration of use.

DESIGN AND SETTING

A retrospective, population-based, cohort study using administrative data from the Manitoba Population Research Data Repository located at the Manitoba Centre for Health Policy, Canada.

PARTICIPANTS

People without a record of a previous prescription who were prescribed a cannabinoid medication from 1 April 2004 to 1 April 2016 followed for 1 year from the date of first prescription.

MEASUREMENTS

Continuous prescribed cannabinoid medication use was defined as use without a gap exceeding 60 days between prescriptions. The primary outcome was prevalence of continuous prescribed cannabinoid medication use for up to 1 year. A secondary outcome was duration of continuous use. Predictors were socio-demographic characteristics, medical diagnoses and type of cannabinoid medication.

FINDINGS

Among 5452 new users, 18.1% [95% confidence interval (CI) = 17.08-19.12] were still using cannabinoids at 1 year. Median duration of use was 31 days [interquartile range (IQR) = 25-193]. This was highest for nabilone (33 days, IQR = 25-199) and lowest for nabiximols (20 days, IQR = 7-30). Use was longest among 19-45- and 46-64-year-old users and those with the highest socio-economic status. Fibromyalgia [hazard ratio (HR) = 0.89, 95% CI = 0.84-0.95], osteoarthritis (HR = 0.91, 95% CI = 0.82-0.97) and substance use disorder (HR = 0.85, 95% CI = 0.76-0.94) diagnoses were associated with longer use (HR for discontinuation-HR < 1 less discontinuation and longer use). A diagnosis of cancer was associated with shorter use (HR = 2.73, 95% CI = 2.02-3.67).

CONCLUSIONS

In Manitoba, Canada approximately 18% of people prescribed cannabinoid medication continue using for at least 1 year. Duration of use varies with type of cannabinoid medication, age, socio-economic status and dagnosis.

Nabilone for non-motor symptoms of Parkinson's disease: a randomized placebo-controlled, double-blind, parallel-group, enriched enrolment randomized withdrawal study (The NMS-Nab Study)

Although open-label observations report a positive effect of cannabinoids on non-motor symptoms (NMS) in Parkinson's disease (PD) patients, these effects remain to be investigated in a controlled trial for a broader use in NMS in PD patients. Therefore, we decided to design a proof-of-concept study to assess the synthetic cannabinoid nabilone for the treatment of NMS. We hypothesize that nabilone will improve NMS in patients with PD and have a favorable safety profile. The NMS-Nab Study is as a mono-centric phase II, randomized, placebo-controlled, double-blind, parallel-group, enriched enrollment withdrawal study. The primary efficacy criterion will be the change in Movement Disorders Society-Unified Parkinson's Disease-Rating Scale Part I score between baseline (i.e. randomization) and week 4. A total of 38 patients will have 80% power to detect a probability of 0.231 that an observation in the treatment group is less than an observation in the placebo group using a Wilcoxon rank-sum test with a 0.050 two-sided significance level assuming a true difference of 2.5 points between nabilone and placebo in the primary outcome measure and a standard deviation of the change of 2.4 points. The reduction of harm through an ineffective treatment, the possibility of individualized dosing, the reduction of sample size, and the possible evaluation of the influence of the placebo effect on efficacy outcomes justify this design for a single-centered placebo-controlled investigator-initiated trial of nabilone. This study should be the basis for further evaluations of long-term efficacy and safety of the use of cannabinoids in PD patients.

Pharmaceutical cannabinoid use in Manitoba, 2004/05 to 2014/15: a population-based cross-sectional study

BACKGROUND

Pharmaceutically derived cannabinoids are used for several indications, particularly pain management. The extent of their use from a population perspective is unknown; hence, the aim of this study was to evaluate trends in pharmaceutical cannabinoid use in Manitoba.

METHODS

This was a retrospective population-based cross-sectional study using administrative data from the Manitoba Centre for Health Policy. Pharmaceutical cannabinoid users residing in Manitoba from Apr. 1, 2004, to Mar. 31, 2015 were identified. We assessed the annual prevalence and incidence of pharmaceutical cannabinoid use, and the sociodemographic characteristics and medical conditions of users.

RESULTS

We identified 5181 people who received at least 1 prescription for a pharmaceutical cannabinoid over the study period, 5033 of whom received their first prescription after Apr. 1, 2004. Nabilone accounted for 73 650 (96.0%) of all prescriptions dispensed; dronabinol was discontinued during the study period. The annual prevalence rate of use increased by 527.2%, from 21.5 (95% confidence interval [CI] 21.4-21.6) users per 100 000 people in 2004/05 to 134.9 (95% CI 134.7-135.1) users per 100 000 people in 2014/15. The annual incidence rate increased by 413.3%, from 12.1 (95% CI 12.1-12.2) users per 100 000 person-years in 2004/05 to 62.2 (95% CI 62.1-62.4) users per 100 000 person-years in 2014/15. The highest use was among older adults aged 46-64 years, females and urban area residents. One-third of incident users (1775 [35.3%]) had a diagnosis of fibromyalgia in a 2-year period before their first cannabinoid prescription. General practitioners initiated almost half (2350 [46.7%]) of first prescriptions, and anesthesiologists/pain specialists initiated one-quarter (1299 [25.8%]).

INTERPRETATION

The prevalence and incidence of pharmaceutical cannabinoid use increased over time. These findings provide insight into the use of cannabinoids before the introduction of recreational marijuana, which may affect this trend.

Addictive potential of novel treatments for refractory depression and anxiety

Treatment-resistant mood disorders and anxiety disorders require intensive treatment, but treatment options should balance benefits and adverse effects or other potential detrimental effects on patients, including the risk of developing prescription medication addiction. Some of the newer treatment modalities for mood and anxiety disorders may have similar properties to benzodiazepines. The goal of this review was to identify the potential for developing dependence on the novel treatment approaches to treatment-resistant depression and refractory anxiety disorders. PubMed, MEDLINE, PsycINFO, Ovid, Cochrane Library, and Google Scholar were searched. Ketamine is effective in improving symptoms of major depressive disorder, but with no sustained benefits. Long-term use of oral or intranasal ketamine formulations may be associated with the risk of developing dependence. Augmentation of stimulant medication is usually effective for residual symptoms of depression, but the effects are usually short lasting and there is a potential for abuse. Synthetic cannabinoids and medicinal cannabis are increasingly being prescribed for a number of medical conditions, including anxiety disorders, without enough evidence about their efficacy and with the risk of patients developing dependence. In summary, benzodiazepines, ketamine, stimulant medications, and cannabinoids have some common characteristics, including short-lasting benefits and the risk of developing prescription medication addiction with longer use. All of these treatments may raise ethical dilemmas about the appropriateness of prescribing these medications in the long run for patients with depression and anxiety disorders.

Update on Treatment Guideline in Fibromyalgia Syndrome with Focus on Pharmacology

Fibromyalgia syndrome (FMS) is a chronic condition with unknown aetiology. The pathophysiology of the disease is incompletely understood; despite advances in our knowledge with regards to abnormal central and peripheral pain processing, and hypothalamo-pituitary-adrenal dysfunction, there is no clear specific pathophysiological therapeutic target. The management of this complex condition has thus perplexed the medical community for many years, and several national and international guidelines have aimed to address this complexity. The most recent guidelines from European League Against Rheumatism (EULAR) (2016), Canadian Pain Society (2012), and The Association of the Scientific Medical Societies in Germany (AWMF) (2012) highlight the change in attitudes regarding the overall approach to FMS, but offer varying advice with regards to the use of pharmacological agents. Amitriptyline, Pregabalin and Duloxetine are used most commonly in FMS and though modestly effective, are useful adjunctive treatment to non-pharmaceutical measures.

Using Social Listening Data to Monitor Misuse and Nonmedical Use of Bupropion: A Content Analysis

Background

The nonmedical use of pharmaceutical products has become a significant public health concern. Traditionally, the evaluation of nonmedical use has focused on controlled substances with addiction risk. Currently, there is no effective means of evaluating the nonmedical use of noncontrolled antidepressants.

Objective

Social listening, in the context of public health sometimes called infodemiology or infoveillance, is the process of identifying and assessing what is being said about a company, product, brand, or individual, within forms of electronic interactive media. The objectives of this study were (1) to determine whether content analysis of social listening data could be utilized to identify posts discussing potential misuse or nonmedical use of bupropion and two comparators, amitriptyline and venlafaxine, and (2) to describe and characterize these posts.

Methods

Social listening was performed on all publicly available posts cumulative through July 29, 2015, from two harm-reduction Web forums, Bluelight and Opiophile, which mentioned the study drugs. The acquired data were stripped of personally identifiable identification (PII). A set of generic, brand, and vernacular product names was used to identify product references in posts. Posts were obtained using natural language processing tools to identify vernacular references to drug misuse-related Preferred Terms from the English Medical Dictionary for Regulatory Activities (MedDRA) version 18 terminology. Posts were reviewed manually by coders, who extracted relevant details.

Results

A total of 7756 references to at least one of the study antidepressants were identified within posts gathered for this study. Of these posts, 668 (8.61%, 668/7756) referenced misuse or nonmedical use of the drug, with bupropion accounting for 438 (65.6%, 438/668). Of the 668 posts, nonmedical use was discouraged by 40.6% (178/438), 22% (22/100), and 18.5% (24/130) and encouraged by 12.3% (54/438), 10% (10/100), and 10.8% (14/130) for bupropion, amitriptyline, and venlafaxine, respectively. The most commonly reported desired effects were similar to stimulants with bupropion, sedatives with amitriptyline, and dissociatives with venlafaxine. The nasal route of administration was most frequently reported for bupropion, whereas the oral route was most frequently reported for amitriptyline and venlafaxine. Bupropion and venlafaxine were most commonly procured from health care providers, whereas amitriptyline was most commonly obtained or stolen from a third party. The Fleiss kappa for interrater agreement among 20 items with 7 categorical response options evaluated by all 11 raters was 0.448 (95% CI 0.421-0.457).

Conclusions

Social listening, conducted in collaboration with harm-reduction Web forums, offers a valuable new data source that can be used for monitoring nonmedical use of antidepressants. Additional work on the capabilities of social listening will help further delineate the benefits and limitations of this rapidly evolving data source.

Effects of zolpidem alone and in combination with nabilone on cannabis withdrawal and a laboratory model of relapse in cannabis users

RATIONALE

Each year, over 300,000 individuals in the USA enter treatment for cannabis use disorder (CUD). The development of effective pharmacotherapy for CUD is a priority.

OBJECTIVE

This placebo-controlled study examined the effects of zolpidem alone and in combination with nabilone on cannabis withdrawal and a laboratory measure of relapse.

METHODS

Eleven daily, non-treatment-seeking cannabis users completed three, 8-day inpatient phases; each phase tested a different medication condition in counter-balanced order. On the first day of each phase, participants were administered placebo capsules t.i.d. and smoked experimenter-administered active cannabis (5.6 % Δ(9)-tetrahydrocannabinol (THC)). On days 2-8, the participants were administered capsules containing either placebo (0 mg at 0900, 1800, and 2300 hours), zolpidem (0 mg at 0900 and 1800, and 12.5 mg at 2300), or zolpidem (12.5 mg at 2300) and nabilone (3 mg at 0900 and 1800). Cannabis withdrawal, subjective capsule effects, and cognitive performance were examined on days 3-4, when only inactive cannabis (0.0 % THC) was available for self-administration. "Relapse" was measured on days 5-8, when participants could self-administer active cannabis.

RESULTS

Both medication conditions decreased withdrawal-related disruptions in sleep, but only zolpidem in combination with nabilone decreased withdrawal-related disruptions in mood and food intake relative to placebo. Zolpidem in combination with nabilone, but not zolpidem alone, decreased self-administration of active cannabis. Zolpidem in combination with nabilone also produced small increases in certain abuse-related subjective capsule ratings, while zolpidem alone did not. Neither medication condition altered cognitive performance.

CONCLUSIONS

Clinical testing of nabilone, either alone, or in combination with zolpidem is warranted.

Cannabinoids: Medical implications

Herbal cannabis has been used for thousands of years for medical purposes. With elucidation of the chemical structures of tetrahydrocannabinol (THC) and cannabidiol (CBD) and with discovery of the human endocannabinoid system, the medical usefulness of cannabinoids has been more intensively explored. While more randomized clinical trials are needed for some medical conditions, other medical disorders, like chronic cancer and neuropathic pain and certain symptoms of multiple sclerosis, have substantial evidence supporting cannabinoid efficacy. While herbal cannabis has not met rigorous FDA standards for medical approval, specific well-characterized cannabinoids have met those standards. Where medical cannabis is legal, patients typically see a physician who "certifies" that a benefit may result. Physicians must consider important patient selection criteria such as failure of standard medical treatment for a debilitating medical disorder. Medical cannabis patients must be informed about potential adverse effects, such as acute impairment of memory, coordination and judgment, and possible chronic effects, such as cannabis use disorder, cognitive impairment, and chronic bronchitis. In addition, social dysfunction may result at work/school, and there is increased possibility of motor vehicle accidents. Novel ways to manipulate the endocannbinoid system are being explored to maximize benefits of cannabinoid therapy and lessen possible harmful effects.

Clinical Use of Cannabinoids for Symptom Control in Multiple Sclerosis

The endocannabinoid system was discovered in 1988 but has received little attention for its potential therapeutic possibilities. That has started to change, and since 2000, a significant number of clinical trials of cannabinoids, principally for the control of spasticity in multiple sclerosis, have been undertaken. These studies have been difficult because of the nature of the disease and have involved patients for whom other therapies have failed or proved inadequate. This paper outlines the background to the use of cannabinoids available and discusses the principles of practice associated with their safe use. The focus has been on nabiximols, being the most studied and the only cannabinoid that has been both adequately researched for use in multiple sclerosis and granted a license by the regulators. However, what has emerged is that the effect for many patients can be much wider than just control of spasticity. Within and outside of neurology there seems to be an expanding range of possibilities for the therapeutic use of cannabinoids.

The efficacy of nabilone, a synthetic cannabinoid, in the treatment of PTSD-associated nightmares: A preliminary randomized, double-blind, placebo-controlled cross-over design study

OBJECTIVE

Investigate the efficacy of nabilone capsules (NAB) in reducing the frequency and intensity of nightmares in subjects with PTSD.

PATIENTS AND METHODS

Canadian male military personnel with PTSD, who despite standard treatment continued to experience trauma-related nightmares, received double-blind treatment with 0.5mg NAB or placebo (PBO), and then titrated to the effective dose (nightmare suppression) or reaching a maximum of 3.0mg. Subjects were followed for 7 weeks and then, following a 2-week washout period, were titrated with the other study treatment and followed for an additional 7 weeks. The modified intent-to-treat (mITT) population, which included all treated subjects that met inclusion/exclusion criteria, was analyzed.

RESULTS

Ten subjects were included in the mITT population. The mean reduction in nightmares as measured by the CAPS Recurring and Distressing Dream scores were -3.6 ± 2.4 and -1.0 ± 2.1 in the NAB and PBO groups, respectively (p=0.03). Mean global improvement as measured by the Clinical Global Impression of Change (CGI-C) was 1.9 ± 1.1 (i.e. much improved) and 3.2 ± 1.2 (i.e. minimally improved) in the NAB and PBO groups, respectively (p=0.05) Five out of 10 (50%) were much improved on NAB versus 1 out of 9 (11%) on PBO. Results for the General Well Being Questionnaire (WBQ) were 20.8 ± 22 and -0.4 ± 20.6 in the NAB and PBO groups, respectively (p=0.04). The proportion of subjects who experienced a treatment-related occurrence of adverse events was 50% in the NBO group and 60% in the PBO group. No event was severe nor resulted in a drop-out. This study is registered with Health Canada.

CONCLUSION

In this small sample NAB provided significant relief for military personnel with PTSD, indicating that it shows promise as a clinically-relevant treatment for patients with nightmares and a history of non-response to traditional therapies. These findings need to be replicated in a larger cohort. There is a need for further exploration of the effect of nabilone on other symptoms of PTSD such as re-experiencing, hyper vigilance and insomnia.

The subjective psychoactive effects of oral dronabinol studied in a randomized, controlled crossover clinical trial for pain

BACKGROUND

Many cannabinoid medications are approved in North America or in phase III trials, such as dronabinol, nabilone, or nabiximols. Little is known about their subjective psychoactive effects when used for pain management. We hypothesized that when used for pain, dronabinol has psychoactive effects in a dose-response relationship, whose peak effects are comparable with smoking marijuana.

METHODS

This was a randomized controlled trial of single dose placebo, 10 or 20 mg dronabinol in 30 chronic noncancer pain patients taking opioids and not using marijuana. Participants completed the Addiction Research Center Inventory (ARCI) hourly for 8 hours during 3 monitored sessions. Comparison sample was the ARCI ratings in participants with no pain (N=20), monitored every 30 minutes after smoking a 1.99% THC (low) and a 3.51% (high strength) marijuana cigarette.

RESULTS

The 10 and 20 mg dronabinol doses had significantly elevated scores over time on 4/5 subscales versus placebo (P<0.05). Average daily morphine use, total pain relief (TOTPAR), age, sex, and baseline pain level were not significant covariates. ARCI peak effects at 2 hours were similar to peak effects of smoked marijuana at 30 minutes (P=0.80, 10 mg=low strength, 20 mg=high strength).

CONCLUSIONS

In pain patients, oral dronabinol has similar psychoactive effects to smoking marijuana. This risk must be considered in any decision to prescribe cannabinoid medications for pain.

Use of a synthetic cannabinoid in a correctional population for posttraumatic stress disorder-related insomnia and nightmares, chronic pain, harm reduction, and other indications: a retrospective evaluation

Nabilone is a synthetic cannabinoid that has shown promise for the treatment of posttraumatic stress disorder (PTSD)-related insomnia and nightmares as well as efficacy in the management of chronic pain. It has also been proposed for harm reduction in cannabis dependence. Its effectiveness for management of concurrent disorders in seriously mentally ill correctional populations has not been evaluated. This retrospective study of 104 male inmates with serious mental illness prescribed nabilone analyzes the indications, efficacy, and safety of its use. Medications discontinued with the initiation of nabilone were also reviewed. The results showed nabilone targeting a mean of 3.5 indications per patient, thus likely reducing polypharmacy risk. The mean final dosage was 4.0 mg. Results indicated significant improvement in PTSD-associated insomnia, nightmares, PTSD symptoms, and Global Assessment of Functioning and subjective improvement in chronic pain. Medications associated with greater risk for adverse effects or abuse than nabilone were often able to be discontinued with the initiation of nabilone, most often antipsychotics and sedative/hypnotics. There was no evidence of abuse within this high-risk population or reduction of efficacy when nabilone was given in powder form with water rather than as a capsule. This study supports the promise of nabilone as a safe, effective treatment for concurrent disorders in seriously mentally ill correctional populations. Prospective, randomized controlled trials are required to confirm our preliminary results. Follow-up in the community will be required to confirm effectiveness in harm reduction.

Neuropathic orofacial pain: cannabinoids as a therapeutic avenue

Neuropathic orofacial pain (NOP) exists in several forms including pathologies such as burning mouth syndrome (BMS), persistent idiopathic facial pain (PIFP), trigeminal neuralgia (TN) and postherpetic neuralgia (PHN). BMS and PIFP are classically diagnosed by excluding other facial pain syndromes. TN and PHN are most often diagnosed based on a typical history and presenting pain characteristics. The pathophysiology of some of these conditions is still unclear and hence treatment options tend to vary and include a wide variety of treatments including cognitive behaviour therapy, anti-depressants, anti-convulsants and opioids; however such treatments often have limited efficacy with a great amount of inter-patient variability and poorly tolerated side effects. Analgesia is one the principal therapeutic targets of the cannabinoid system and many studies have demonstrated the efficacy of cannabinoid compounds in the treatment of neuropathic pain. This review will investigate the potential use of cannabinoids in the treatment of symptoms associated with NOP.

Review of pharmacological therapies in fibromyalgia syndrome

This review addresses the current status of drug therapy for the management of fibromyalgia syndrome (FMS) and is based on interdisciplinary FMS management guidelines, meta-analyses of drug trial data, and observational studies. In the absence of a single gold-standard medication, patients are treated with a variety of drugs from different categories, often with limited evidence. Drug therapy is not mandatory for the management of FMS. Pregabalin, duloxetine, milnacipran, and amitriptyline are the current first-line prescribed agents but have had a mostly modest effect. With only a minority of patients expected to experience substantial benefit, most will discontinue therapy because of either a lack of efficacy or tolerability problems. Many drug treatments have undergone limited study and have had negative results. It is unlikely that these failed pilot trials will undergo future study. However, medications, though imperfect, will continue to be a component of treatment strategy for these patients. Both the potential for medication therapy to relieve symptoms and the potential to cause harm should be carefully considered in their administration.

Subjective, cognitive and cardiovascular dose-effect profile of nabilone and dronabinol in marijuana smokers

Marijuana dependence is a substantial public health problem, with existing treatments showing limited efficacy. In laboratory and clinical studies, the cannabinoid receptor 1 agonist oral Δ9tetrahydrocannabinol (THC; dronabinol) has been shown to decrease marijuana withdrawal but not relapse. Dronabinol has poor bioavailability, potentially contributing to its failure to decrease relapse. The synthetic THC analogue, nabilone, has better bioavailability than dronabinol. We therefore aimed to characterize nabilone's behavioral and physiological effects across a range of acute doses in current marijuana smokers and compare these with dronabinol's effects. Participants (4 female; 10 male) smoking marijuana 6.6 (standard deviation = 0.7) days/week completed this outpatient, within-subjects, double-blind, randomized protocol. Over seven sessions, the time-dependent subjective, cognitive and cardiovascular effects of nabilone (2, 4, 6, 8 mg), dronabinol (10, 20 mg) and placebo were assessed. Nabilone (4, 6, 8 mg) and dronabinol (10, 20 mg) increased ratings of feeling a good effect, a strong effect and/or 'high' relative to placebo; nabilone had a slower onset of peak subjective effects than dronabinol. Nabilone (6, 8 mg) modestly lowered psychomotor speed relative to placebo and dronabinol. There were dose-dependent increases in heart rate after nabilone, and nabilone (2 mg) and dronabinol (10 mg) decreased systolic blood pressure. Thus, nabilone produced sustained, dose-related increases in positive mood, few cognitive decrements and lawful cardiovascular alterations. It had a longer time to peak effects than dronabinol, and effects were more dose-related, suggesting improved bioavailability. Nabilone was well tolerated by marijuana smokers, supporting further testing as a potential medication for marijuana dependence.

Nabilone decreases marijuana withdrawal and a laboratory measure of marijuana relapse

Few individuals seeking treatment for marijuana use achieve sustained abstinence. The cannabinoid receptor agonist, Δ(9)-tetrahydrocannabinol (THC; dronabinol), decreases marijuana withdrawal symptoms, yet does not decrease marijuana use in the laboratory or clinic. Dronabinol has poor bioavailability, which may contribute to its poor efficacy. The FDA-approved synthetic analog of THC, nabilone, has higher bioavailability and clearer dose-linearity than dronabinol. This study tested whether nabilone administration would decrease marijuana withdrawal symptoms and a laboratory measure of marijuana relapse relative to placebo. Daily, nontreatment-seeking marijuana smokers (8 men and 3 women), who reported smoking 8.3±3.1 marijuana cigarettes/day completed this within-subject study comprising three, 8-day inpatient phases; each phase tested a different nabilone dose (0, 6, 8 mg/day, administered in counter-balanced order on days 2-8). On the first inpatient day, participants took placebo capsules and smoked active marijuana (5.6% THC) at six timepoints. For the next 3 days, they had the opportunity to self-administer placebo marijuana (0.0% THC; withdrawal), followed by 4 days in which active marijuana was available for self-administration (5.6% THC; relapse). Both nabilone dose conditions decreased marijuana relapse and reversed withdrawal-related irritability and disruptions in sleep and food intake (p<0.05). Nabilone (8 mg/day) modestly worsened psychomotor task performance. Neither dose condition increased ratings of capsule 'liking' or desire to take the capsules relative to placebo. Thus, nabilone maintenance produced a robust attenuation of marijuana withdrawal symptoms and a laboratory measure of relapse even with once per day dosing. These data support testing of nabilone for patients seeking marijuana treatment.

[Drug therapy of fibromyalgia syndrome. Systematic review, meta-analysis and guideline]

BACKGROUND

The scheduled update to the German S3 guidelines on fibromyalgia syndrome (FMS) by the Association of the Scientific Medical Societies ("Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften", AWMF; registration number 041/004) was planned starting in March 2011.

MATERIALS AND METHODS

The development of the guidelines was coordinated by the German Interdisciplinary Association for Pain Therapy ("Deutsche Interdisziplinären Vereinigung für Schmerztherapie", DIVS), 9 scientific medical societies and 2 patient self-help organizations. Eight working groups with a total of 50 members were evenly balanced in terms of gender, medical field, potential conflicts of interest and hierarchical position in the medical and scientific fields. Literature searches were performed using the Medline, PsycInfo, Scopus and Cochrane Library databases (until December 2010). The grading of the strength of the evidence followed the scheme of the Oxford Centre for Evidence-Based Medicine. The recommendations were based on level of evidence, efficacy (meta-analysis of the outcomes pain, sleep, fatigue and health-related quality of life), acceptability (total dropout rate), risks (adverse events) and applicability of treatment modalities in the German health care system. The formulation and grading of recommendations was accomplished using a multi-step, formal consensus process. The guidelines were reviewed by the boards of the participating scientific medical societies.

RESULTS AND CONCLUSION

Amitriptyline and-in case of comorbid depressive disorder or generalized anxiety disorder-duloxetine are recommended. Off-label use of duloxetine and pregabalin can be considered in case of no comorbid mental disorder. Strong opioids are not recommended. The English full-text version of this article is available at SpringerLink (under "Supplemental").

Nabilone for the treatment of medication overuse headache: results of a preliminary double-blind, active-controlled, randomized trial

Medication overuse headache (MOH) is a severe burden to sufferers and its treatment has few evidence-based indications. The aim of this study is to evaluate efficacy and safety of nabilone in reducing pain and frequency of headache, the number of analgesic intake and in increasing the quality of life on patients with long-standing intractable MOH. Thirty MOH patients were enrolled at the University of Modena’s Interdepartmental Centre for Research on Headache and Drug Abuse (Italy) in a randomized, double-blind, active-controlled, crossover study comparing nabilone 0.5 mg/day and ibuprofen 400 mg. The patients received each treatment orally for 8 weeks (before nabilone and then ibuprofen or vice versa), with 1 week wash-out between them. Randomization and allocation (ratio 1:1) were carried out by an independent pharmacy through a central computer system. Participants, care givers, and those assessing the outcomes were blinded to treatment sequence. Twenty-six subjects completed the study. Improvements from baseline were observed with both treatments. However, nabilone was more effective than ibuprofen in reducing pain intensity and daily analgesic intake (p < 0.05); moreover, nabilone was the only drug able to reduce the level of medication dependence (−41 %, p < 0.01) and to improve the quality of life (p < 0.05). Side effects were uncommon, mild and disappeared when nabilone was discontinued. This is the first randomized controlled trial demonstrating the benefits of nabilone on headache, analgesic consumption and the quality of life in patients with intractable MOH. This drug also appears to be safe and well-tolerated. Larger scale studies are needed to confirm these preliminary findings.

Blurred boundaries: the therapeutics and politics of medical marijuana

For 5 millennia, Cannabis sativa has been used throughout the world medically, recreationally, and spiritually. From the mid-19th century to the 1930s, American physicians prescribed it for a plethora of indications, until the federal government started imposing restrictions on its use, culminating in 1970 with the US Congress classifying it as a Schedule I substance, illegal, and without medical value. Simultaneous with this prohibition, marijuana became the United States' most widely used illicit recreational drug, a substance generally regarded as pleasurable and relaxing without the addictive dangers of opioids or stimulants. Meanwhile, cannabis never lost its cachet in alternative medicine circles, going mainstream in 1995 when California became the first of 16 states to date to legalize its medical use, despite the federal ban. Little about cannabis is straightforward. Its main active ingredient, δ-9-tetrahydrocannabinol, was not isolated until 1964, and not until the 1990s were the far-reaching modulatory activities of the endocannabinoid system in the human body appreciated. This system's elucidation raises the possibility of many promising pharmaceutical applications, even as draconian federal restrictions that hamstring research show no signs of softening. Recreational use continues unabated, despite growing evidence of marijuana's addictive potential, particularly in the young, and its propensity for inducing and exacerbating psychotic illness in the susceptible. Public approval drives medical marijuana legalization efforts without the scientific data normally required to justify a new medication's introduction. This article explores each of these controversies, with the intent of educating physicians to decide for themselves whether marijuana is panacea, scourge, or both. PubMed searches were conducted using the following keywords: medical marijuana, medical cannabis, endocannabinoid system, CB1 receptors, CB2 receptors, THC, cannabidiol, nabilone, dronabinol, nabiximols, rimonabant, marijuana legislation, marijuana abuse, marijuana dependence, and marijuana and schizophrenia. Bibliographies were hand searched for additional references relevant to clarifying the relationships between medical and recreational marijuana use and abuse.

Treating pain in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an inflammatory, demyelinating, central nervous system disease that frequently causes pain.

AREAS COVERED

This article reviews the current literature and describes the therapeutic options for treating MS-related pain. The reader will be provided with current, evidence-based knowledge about the treatment of MS-related pain, and the review will take a practical approach to the various drugs for treating pain, including starting dose, titration and side effects.

EXPERT OPINION

Only cannabinoids have been assessed in randomized, controlled trials. Because of the concern regarding the risk of abuse and psychiatric adverse events, published guidelines as well as expert recommendations suggest using them as second-line therapy only. Hence, current treatment should be based on the general principles for treating peripheral neuropathic pain, taking into account drug-induced adverse effects.

Central and peripheral cannabinoid receptors as therapeutic targets in the control of food intake and body weight

The endocannabinoid system consists of lipid-derived agonists that activate cannabinoid (CB) receptors. CB receptor agonists, namely, the phytocannabinoid Δ(9)-THC and the endocannabinoid anandamide, increase hunger sensation and food intake. These discoveries led to the clinical use of Δ(9)-THC derivatives for the treatment of cancer and HIV-related nausea and cachexia. Animal studies clarified the important role of CB1 receptors in the hypothalamus and in the limbic system in mediating orexigenic effects. In parallel, data on CB1-specific blockade either by drugs or by genetic ablation further demonstrated that CB1 inhibition protects against weight gain induced by high-fat feeding and reduces body weight in obese animals and humans. The mechanisms of weight reduction by CB1 blockade are complex: they comprise interactions with several orexigenic and anorexigenic neuropeptides and hormones, regulation of sympathetic activity, influences on mitochondrial function, and on lipogenesis. Although these mechanisms appear to be mainly mediated by the CNS, weight loss also occurs when drugs that do not reach CNS concentrations sufficient to inhibit CB1 signaling are used. The development of peripherally restricted CB1 inverse agonists and antagonists opened new routes in CB1 pharmacology because centrally acting CB1 inverse agonists, e.g., rimonabant and taranabant, exerted unacceptable side effects that precluded their further development and application as weight loss drugs. Tissue and circulating endocannabinoid concentrations are often increased in animal models of obesity and in obese humans, especially those with visceral fat accumulation. Thus, further research on CB1 inhibition is still promising to treat human obesity.

Gastroparesis: concepts, controversies, and challenges

Patients with gastroparesis often present a challenge to the treating physician. Postprandial symptoms with nausea and vomiting may not only lead to nutritional and metabolic consequences, but also cause significant disruptions to social activities that often center around food. While the definition of gastroparesis focuses on impaired gastric emptying, treatment options that affect gastric function are limited and often disappointing. The female predominance, the mostly idiopathic nature of the illness with a common history of abuse, and coexisting anxiety or depression show parallels with other functional disorders of the gastrointestinal tract. These parallels provided the rationale for some initial studies investigating alternative therapies that target the brain rather than the stomach. This emerging shift in medical therapy comes at a time when clinical studies suggest that gastric electrical stimulation may exert its effects by modulating visceral sensory processing rather than altering gastric motility. Physiologic and detailed anatomic investigations also support a more complex picture with different disease mechanisms, ranging from impaired accommodation to apparent visceral hypersensitivity or decreased interstitial cells of Cajal to inflammatory infiltration of myenteric ganglia. Delayed gastric emptying remains the endophenotype defining gastroparesis. However, our treatment options go beyond prokinetics and may allow us to improve the quality of life of affected individuals.

Medical marijuana: medical necessity versus political agenda

Marijuana is classified by the Drug Enforcement Agency (DEA) as an illegal Schedule I drug which has no accepted medical use. However, recent studies have shown that medical marijuana is effective in controlling chronic non-cancer pain, alleviating nausea and vomiting associated with chemotherapy, treating wasting syndrome associated with AIDS, and controlling muscle spasms due to multiple sclerosis. These studies state that the alleviating benefits of marijuana outweigh the negative effects of the drug, and recommend that marijuana be administered to patients who have failed to respond to other therapies. Despite supporting evidence, the DEA refuses to reclassify marijuana as a Schedule II drug, which would allow physicians to prescribe marijuana to suffering patients. The use of medical marijuana has continued to gain support among states, and is currently legal in 16 states and the District of Columbia. This is in stark contrast to the federal government's stance of zero-tolerance, which has led to a heated legal debate in the United States. After reviewing relevant scientific data and grounding the issue in ethical principles like beneficence and nonmaleficence, there is a strong argument for allowing physicians to prescribe marijuana. Patients have a right to all beneficial treatments and to deny them this right violates their basic human rights.

Separate and combined effects of the cannabinoid agonists nabilone and Δ⁹-THC in humans discriminating Δ⁹-THC

BACKGROUND

Agonist replacement treatment is a promising strategy to manage cannabis-use disorders. The aim of this study was to assess the combined effects of the synthetic cannabinoid agonist nabilone and Δ⁹-tetrahydrocannabinol (Δ⁹-THC) using drug-discrimination procedures, which are sensitive to drug interactions. Testing the concurrent administration of nabilone and Δ⁹-THC was also conducted to provide initial safety and tolerability data, which is important because cannabis users will likely lapse during treatment.

METHODS

Six cannabis users learned to discriminate 30 mg oral Δ⁹-THC from placebo and then received nabilone (0, 1 and 3mg) and Δ⁹-THC (0, 5, 15 and 30 mg), alone and in combination. Subjects completed the multiple-choice procedure to assess drug reinforcement, and self-report, task performance and physiological measures were collected.

RESULTS

Δ⁹-THC and nabilone alone shared discriminative-stimulus effects with the training dose of Δ⁹-THC, increased crossover point on the multiple-choice procedure, produced overlapping subject ratings and decreased skin temperature. Nabilone alone also elevated heart rate. In combination, nabilone shifted the discriminative-stimulus effects of Δ⁹-THC leftward/upward and enhanced Δ⁹-THC effects on the other outcome measures.

CONCLUSIONS

These results replicate a previous study demonstrating that nabilone shares agonist effects with the active constituent of cannabis in cannabis users, and contribute further by indicating that nabilone would likely be safe and well tolerated when combined with cannabis. These data support the conduct of future studies to determine if nabilone treatment would produce cross-tolerance to the abuse-related effects of cannabis and reduce cannabis use.