Vaporized D-limonene selectively mitigates the acute anxiogenic effects of Δ9-tetrahydrocannabinol in healthy adults who intermittently use cannabis.

BACKGROUND: Cannabis contains hundreds of chemical constituents beyond delta-9-tetrahydrocannabinol (THC), which is believed to drive most of its acute pharmacodynamic effects. The entourage effect theory asserts that non-THC constituents can impact acute cannabis effects, but few empirical studies have systematically evaluated this theory in humans. This study assessed whether the cannabis terpenoid d-limonene mitigates the acute anxiogenic effects of THC. METHODS: Twenty healthy adults completed nine, double-blind outpatient sessions in which they inhaled vaporized THC alone (15mg or 30mg), d-limonene alone (1mg or 5mg), the same doses of THC and d-limonene together, or placebo; a subset of participants (n=12) completed a tenth session in which 30mg THC+15mg d-limonene was administered. Outcomes included subjective drug effects, cognitive/psychomotor performance, vital signs, and plasma THC and d-limonene concentrations. RESULTS: When d-limonene was administered alone, pharmacodynamic outcomes did not differ from placebo. Administration of 15mg and 30mg THC alone produced subjective, cognitive, and physiological effects typical of acute cannabis exposure. Ratings of anxiety-like subjective effects qualitatively decreased as d-limonene dose increased and concurrent administration of 30mg THC+15mg d-limonene significantly reduced ratings of "anxious/nervous" and "paranoid" compared with 30mg THC alone. Other pharmacodynamic effects were unchanged by d-limonene. D-limonene plasma concentrations were dose orderly, and concurrent administration of d-limonene did not alter THC pharmacokinetics. CONCLUSIONS: D-limonene selectively attenuated THC-induced anxiogenic effects, suggesting this terpenoid could increase the therapeutic index of THC. Future research should determine whether this effect extends to oral dose formulations and evaluate the interactions between other cannabis terpenoids or cannabinoids and THC.

Feasibility of a cannabidiol-dominant cannabis-based medicinal product for the treatment of long COVID symptoms: A single-arm open-label feasibility trial.

AIMS: To conduct a single-arm open-label feasibility trial of the safety and tolerability of a full-spectrum cannabidiol (CBD)-dominant cannabis-based medicinal product for treating the symptoms of long COVID. METHODS: The treatment phase ran for a total of 21 weeks, followed by ~3 weeks without the study drug. Participants received up to 3 mL of MediCabilis 5% CBD Oil (50 mg CBD/mL, <2 mg δ-9-tetrahydrocannabinol/mL) per day orally. Monthly patient-reported outcome measures of common symptoms and daily self-report of symptoms were collected via a smartphone app. Key measures of heart rate, activity, sleep and oxygen saturation were assessed using wearable technology. RESULTS: Twelve (1 male, 11 female) individuals diagnosed with long COVID were recruited into the trial. All participants adhered to the treatment protocol for the duration of the study and there were no serious adverse events. Response rates for the research assessments were high with over 90% completion of patient-reported outcome measures and daily self-report. CONCLUSION: The study drug was safe and well-tolerated, demonstrating feasibility of CBD-dominant cannabis-based medicinal products in individuals diagnosed with long COVID. However, there were limitations in research design related to recruitment strategy demonstrating a lack of feasibility in the approach implemented in this study. Future work with larger samples and incorporating a control group are required to test the efficacy of this treatment.

Effectiveness and Safety of Cannabinoids as an Add-On Therapy in the Treatment of Resistant Spasticity in Multiple Sclerosis: A Systematic Review.

Background: Spasticity continues to be a very prevalent, highly invalidating, and difficult-to-manage symptom in patients with multiple sclerosis (MS). The aim of this systematic review is to evaluate the effectiveness of the use of cannabis and cannabinoids in these patients, evaluating its use as an additional therapy. Methods: We performed a systematic review of the literature searching in the major scientific databases (PubMed, Scopus, EMBASE, WOS, and Cochrane Library) for articles from January 2017 to May 2022 containing information about the effectiveness of cannabis and cannabinoids in patients with insufficient response to first-line oral antispastic treatment. Results: A total of five medium high-quality articles were selected to be part of the study and all evaluated the effectiveness of the tetrahydrocannabinol (THC) and cannabidiol (CBD) spray. The effectiveness of this drug and the significant improvements are produced on the patient-related spasticity assessment scales, obtaining improvement up to 45%; and on quality of life, producing a decrease in the appearance of symptoms related to spasticity, as well as an increase in the development of basic activities of daily living. The average dose is 5-7 sprays/day. The discontinuation rate for these treatments is around 40% due to lack of effectiveness and adverse events. All reported adverse effects are mild to moderate in severity and their incidence is ∼17%, although this figure tends to decrease with drug use. Conclusions: Adding the THC:CBD sprays have been shown to be more effective in treating MS spasticity than optimizing the dose of first-line antispastic drugs in selected responders patients. The safety and tolerability profiles remain in line with those obtained in other trials. More patients would benefit from treatment if the initial response search period was extended.

Place of therapeutic cannabis in France and safety data: A literature review.

OBJECTIVES: To date, very few cannabis-based specialities are authorised on the French market despite a growing demand from patients and health professionals. The objective of this study is to review the tolerance profile and the French legislative status of the two main cannabinoids used for therapeutic purposes: tetrahydrocannabiol (THC) associated with psychoactive effects and non-psychoactive cannabidiol (CBD). METHODS: This review is based on relevant articles retrieved by a search in Google Scholar and PubMed databases and on an assessment of the legal texts and summaries of product characteristics available in France. RESULTS: Evidence for the tolerability of CBD during chronic use is reassuring, but a significant risk of drug interactions exists. THC use appears to be associated with a higher proportion of serious adverse effects, including neuropsychological and cardiovascular effects. Inhaled cannabis appears to be associated with greater toxicity than the oral route. These data are presented together with the pharmacokinetic and pharmacodynamic data of THC and CBD. CONCLUSION: The literature reports several frequent but rarely serious adverse effects of CBD during chronic use as well as a significant risk of drug interactions. THC use seems to be associated with a higher proportion of serious adverse effects compared to CBD, particularly at the neuropsychological and cardiovascular levels. Health professionals should be up to date on the particularities of therapeutic cannabis in terms of efficacy, safety and drug interactions.

Cannabis and cannabinoids for symptomatic treatment for people with multiple sclerosis.

BACKGROUND: Spasticity and chronic neuropathic pain are common and serious symptoms in people with multiple sclerosis (MS). These symptoms increase with disease progression and lead to worsening disability, impaired activities of daily living and quality of life. Anti-spasticity medications and analgesics are of limited benefit or poorly tolerated. Cannabinoids may reduce spasticity and pain in people with MS. Demand for symptomatic treatment with cannabinoids is high. A thorough understanding of the current body of evidence regarding benefits and harms of these drugs is required. OBJECTIVES: To assess benefit and harms of cannabinoids, including synthetic, or herbal and plant-derived cannabinoids, for reducing symptoms for adults with MS. SEARCH METHODS: We searched the following databases from inception to December 2021: MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library), CINAHL (EBSCO host), LILACS, the Physiotherapy Evidence Database (PEDro), the World Health Organisation International Clinical Trials Registry Platform, the US National Institutes of Health clinical trial register, the European Union Clinical Trials Register, the International Association for Cannabinoid Medicines databank. We hand searched citation lists of included studies and relevant reviews. SELECTION CRITERIA: We included randomised parallel or cross-over trials (RCTs) evaluating any cannabinoid (including herbal Cannabis, Cannabis flowers, plant-based cannabinoids, or synthetic cannabinoids) irrespective of dose, route, frequency, or duration of use for adults with MS. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. To assess bias in included studies, we used the Cochrane Risk of bias 2 tool for parallel RCTs and crossover trials. We rated the certainty of evidence using the GRADE approach for the following outcomes: reduction of 30% in the spasticity Numeric Rating Scale, pain relief of 50% or greater in the Numeric Rating Scale-Pain Intensity, much or very much improvement in the Patient Global Impression of Change (PGIC), Health-Related Quality of Life (HRQoL), withdrawals due to adverse events (AEs) (tolerability), serious adverse events (SAEs), nervous system disorders, psychiatric disorders, physical dependence. MAIN RESULTS: We included 25 RCTs with 3763 participants of whom 2290 received cannabinoids. Age ranged from 18 to 60 years, and between 50% and 88% participants across the studies were female.  The included studies were 3 to 48 weeks long and compared nabiximols, an oromucosal spray with a plant derived equal (1:1) combination of tetrahydrocannabinol (THC) and cannabidiol (CBD) (13 studies), synthetic cannabinoids mimicking THC (7 studies), an oral THC extract of Cannabis sativa (2 studies), inhaled herbal Cannabis (1 study) against placebo. One study compared dronabinol, THC extract of Cannabis sativa and placebo, one compared inhaled herbal Cannabis, dronabinol and placebo. We identified eight ongoing studies. Critical outcomes • Spasticity: nabiximols probably increases the number of people who report an important reduction of perceived severity of spasticity compared with placebo (odds ratio (OR) 2.51, 95% confidence interval (CI) 1.56 to 4.04; 5 RCTs, 1143 participants; I2 = 67%; moderate-certainty evidence). The absolute effect was 216 more people (95% CI 99 more to 332 more) per 1000 reporting benefit with cannabinoids than with placebo. • Chronic neuropathic pain: we found only one small trial that measured the number of participants reporting substantial pain relief with a synthetic cannabinoid compared with placebo (OR 4.23, 95% CI 1.11 to 16.17; 1 study, 48 participants; very low-certainty evidence). We are uncertain whether cannabinoids reduce chronic neuropathic pain intensity. • Treatment discontinuation due to AEs: cannabinoids may increase slightly the number of participants who discontinue treatment compared with placebo (OR 2.41, 95% CI 1.51 to 3.84; 21 studies, 3110 participants; I² = 17%; low-certainty evidence); the absolute effect is 39 more people (95% CI 15 more to 76 more) per 1000 people. Important outcomes • PGIC: cannabinoids probably increase the number of people who report 'very much' or 'much' improvement in health status compared with placebo (OR 1.80, 95% CI 1.37 to 2.36; 8 studies, 1215 participants; I² = 0%; moderate-certainty evidence). The absolute effect is 113 more people (95% CI 57 more to 175 more) per 1000 people reporting improvement. • HRQoL: cannabinoids may have little to no effect on HRQoL (SMD -0.08, 95% CI -0.17 to 0.02; 8 studies, 1942 participants; I2 = 0%; low-certainty evidence); • SAEs: cannabinoids may result in little to no difference in the number of participants who have SAEs compared with placebo (OR 1.38, 95% CI 0.96 to 1.99; 20 studies, 3124 participants; I² = 0%; low-certainty evidence); • AEs of the nervous system: cannabinoids may increase nervous system disorders compared with placebo (OR 2.61, 95% CI 1.53 to 4.44; 7 studies, 1154 participants; I² = 63%; low-certainty evidence); • Psychiatric disorders: cannabinoids may increase psychiatric disorders compared with placebo (OR 1.94, 95% CI 1.31 to 2.88; 6 studies, 1122 participants; I² = 0%; low-certainty evidence); • Drug tolerance: the evidence is very uncertain about the effect of cannabinoids on drug tolerance (OR 3.07, 95% CI 0.12 to 75.95; 2 studies, 458 participants; very low-certainty evidence). AUTHORS' CONCLUSIONS: Compared with placebo, nabiximols probably reduces the severity of spasticity in the short-term in people with MS. We are uncertain about the effect on chronic neurological pain and health-related quality of life. Cannabinoids may increase slightly treatment discontinuation due to AEs, nervous system and psychiatric disorders compared with placebo. We are uncertain about the effect on drug tolerance. The overall certainty of evidence is limited by short-term duration of the included studies.

Observational study of medical marijuana as a treatment for treatment-resistant epilepsies.

OBJECTIVES: Medical cannabis formulations with cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) are widely used to treat epilepsy. We studied the safety and efficacy of two formulations. METHODS: We prospectively observed 29 subjects (12 to 46 years old) with treatment-resistant epilepsies (11 Lennox-Gastaut syndrome; 15 with focal or multifocal epilepsy; three generalized epilepsy) were treated with medical cannabis (1THC:20CBD and/or 1THC:50CBD; maximum of 6 mg THC/day) for ≥24 weeks. The primary outcome was change in convulsive seizure frequency from the pre-treatment baseline to the stable optimal dose phase. RESULTS: There were no significant differences during treatment on stable maximal doses for convulsive seizure frequency, seizure duration, postictal duration, or use of rescue medications compared to baseline. No benefits were seen for behavioral disorders or sleep duration; there was a trend for more frequent bowel movements compared to baseline. Ten adverse events occurred in 6/29 patients, all were transient and most unrelated to study medication. No serious adverse events were related to study medication. INTERPRETATION: Our prospective observational study of two high-CBD/low-THC formulations found no evidence of efficacy in reducing seizures, seizure duration, postictal duration, or rescue medication use. Behavioral disorders or sleep duration was unchanged. Study medication was generally well tolerated. The doses of CBD used were lower than prior studies. Randomized trials with larger cohorts are needed, but we found no evidence of efficacy for two CBD:THC products in treating epilepsy, sleep, or behavior in our population.

Review of Available Data for the Efficacy and Effectiveness of Nabiximols Oromucosal Spray (Sativex®) in Multiple Sclerosis Patients with Moderate to Severe Spasticity.

BACKGROUND: Sativex (USAN: nabiximols [NAB]) oromucosal spray is indicated for treatment of multiple sclerosis (MS) patients with moderate to severe spasticity and inadequate response to other antispasticity medications who demonstrate clinically significant improvement during an initial trial of therapy. This narrative review investigated the efficacy and effectiveness of NAB oromucosal spray for moderate to severe MS spasticity by examining spasticity 0-10 numerical rating scale (NRS) data from interventional and observational studies which featured a 4-week trial period as per the European Union-approved label. SUMMARY: Across both study types, clinically relevant and statistically significant reductions in mean MS spasticity 0-10 NRS scores were measured soon after treatment start and were maintained in the mid- to long term in treatment responders. Initial responder rates (≥20% NRS improvement from baseline at week 4) ranged from 47.6% to 81.4%, tending lower in the randomized clinical trials setting. Clinically relevant responder rates (≥30% NRS improvement from baseline at week 12) were similar between study types (range 30-41%) except for one outlier (74% in an observational study). Two open studies reported treatment continuation for ≥18 months in approximately half of patients who initiated treatment. In most longer term studies, symptomatic improvement in MS spasticity was maintained at mean daily dosages of about 6-7 sprays/day. Safety was consistent with the known profile of NAB. KEY MESSAGES: Experimental and observational studies of NAB oromucosal spray recorded similar findings. About half to two-thirds of MS patients who begin treatment will perceive initial symptomatic relief of spasticity within the 4-week trial period. About 40% of patients who initiate treatment will reach the ≥30% NRS improvement threshold at 3 months, comprising the majority of patients who continue long-term treatment. A trial of therapy with NAB is useful to identify patients most likely to gain longer term improvement in spasticity symptoms and discontinue those with insufficient benefit.

Cannabis Dopaminergic Effects Induce Hallucinations in a Patient with Parkinson's Disease.

Cannabis products that contain the tetrahydrocannabinol (THC) cannabinoid are emerging as promising therapeutic agents for the treatment of medical conditions such as chronic pain. THC elicits psychoactive effects through modulation of dopaminergic neurons, thereby altering levels of dopamine in the brain. This case report highlights the complexity associated with medicinal cannabis and the health risks associated with its use. A 57-year-old male with Parkinson's disease was experiencing worsening tremors and vivid hallucinations despite therapy optimization attempts. It was discovered that the patient took cannabis for chronic back pain, and a pharmacogenomics (PGx) test indicated the presence of variants for the COMT and HTR2A genes. These variants could increase dopamine levels and predispose patients to visual hallucinations. Once the cannabis was discontinued, the patient's hallucinations began to slowly dissipate. Cannabis use continues to expand as it gains more acceptance legally and medicinally, but cannabis can affect the response to drugs. This patient case suggests that cannabis use in combination with dopamine-promoting drugs, especially in a patient with genetic variants, can increase the risk for vivid hallucinations. These conditions support the importance of considering herb-drug interactions and PGx data when performing a medication safety review.

Medication overuse headache in patients with chronic migraine using cannabis: A case-referent study.

OBJECTIVE: To examine whether cannabis use predicts medication overuse headache (MOH) in patients with chronic migraine (CM). METHODS: Electronic chart review was conducted by combining the terms "CM," "medication overuse," "cannabis," "cannabidiol," and "tetrahydrocannabinol" for patients seen at our headache clinics from 2015 to 2019. Of 729 charts consecutively screened, 368 met our inclusion criteria, that is, adult patients with CM with ≥1-year CM duration. The following variables were extracted from the included patient charts: MOH diagnosis, age, sex, migraine frequency, current CM duration, current cannabis use duration, overused acute migraine medications, current MOH duration, and types of cannabis products used. Logistic regression was used to identify variables predicting MOH while controlling for remaining predictors. Agglomerative hierarchical clustering (AHC) was conducted to explore natural clusters using all predictor variables. RESULTS: There were 212 patients with CM and MOH (cases; median age 43 years, interquartile range [IQR] 33-54; 177 [83%] females) and 156 patients with CM without MOH (referents; median age 40 years, IQR 31-49; 130 [83%] females). MOH was present in 81% (122/150) of current cannabis users compared with 41% (90/218) in those without cannabis use-adjusted odds ratio 6.3 (95% CI: 3.56 to 11.1, p < 0.0001). Current cannabis use was significantly associated with opioid use (Spearman's rho 0.26, p < 0.0001). Both current cannabis use (rho 0.40, p < 0.0001) and opioid use (rho 0.36, p < 0.0001) were significantly associated with MOH. Similarly, AHC revealed two major natural clusters. Cluster I patients featured 9.3 times higher current cannabis use, 9.2 times higher current opioid use, and 1.8 times higher MOH burden than those in Cluster II (p < 0.0001). CONCLUSION: Cannabis use was significantly associated with increased prevalence of MOH in CM. Bidirectional cannabis-opioid association was observed-use of one was associated with use of the other. Advising patients with CM and MOH to reduce cannabis use may help treat MOH effectively.

Reversing the Psychiatric Effects of Neurodevelopmental Cannabinoid Exposure: Exploring Pharmacotherapeutic Interventions for Symptom Improvement.

Neurodevelopmental exposure to psychoactive compounds in cannabis, specifically THC, is associated with a variety of long-term psychopathological outcomes. This increased risk includes a higher prevalence of schizophrenia, mood and anxiety disorders, and cognitive impairments. Clinical and pre-clinical research continues to identify a wide array of underlying neuropathophysiological sequelae and mechanisms that may underlie THC-related psychiatric risk vulnerability, particularly following adolescent cannabis exposure. A common theme among these studies is the ability of developmental THC exposure to induce long-term adaptations in the mesocorticolimbic system which resemble pathological endophenotypes associated with these disorders. This narrative review will summarize recent clinical and pre-clinical evidence that has elucidated these THC-induced developmental risk factors and examine how specific pharmacotherapeutic interventions may serve to reverse or perhaps prevent these cannabis-related risk outcomes.

Opportunities, Challenges and Pitfalls of Using Cannabidiol as an Adjuvant Drug in COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may lead to coronavirus disease 2019 (COVID-19) which, in turn, may be associated with multiple organ dysfunction. In this review, we present advantages and disadvantages of cannabidiol (CBD), a non-intoxicating phytocannabinoid from the cannabis plant, as a potential agent for the treatment of COVID-19. CBD has been shown to downregulate proteins responsible for viral entry and to inhibit SARS-CoV-2 replication. Preclinical studies have demonstrated its effectiveness against diseases of the respiratory system as well as its cardioprotective, nephroprotective, hepatoprotective, neuroprotective and anti-convulsant properties, that is, effects that may be beneficial for COVID-19. Only the latter two properties have been demonstrated in clinical studies, which also revealed anxiolytic and antinociceptive effects of CBD (given alone or together with Δ9-tetrahydrocannabinol), which may be important for an adjuvant treatment to improve the quality of life in patients with COVID-19 and to limit post-traumatic stress symptoms. However, one should be aware of side effects of CBD (which are rarely serious), drug interactions (also extending to drugs acting against COVID-19) and the proper route of its administration (vaping may be dangerous). Clearly, further clinical studies are necessary to prove the suitability of CBD for the treatment of COVID-19.

Behavioral Battery for Testing Candidate Analgesics in Mice. II. Effects of Endocannabinoid Catabolic Enzyme Inhibitors and ∆9-Tetrahydrocannabinol.

Enhanced signaling of the endocannabinoid (eCB) system through inhibition of the catabolic enzymes monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) has received increasing interest for development of candidate analgesics. This study compared effects of MAGL and FAAH inhibitors with effects of ∆9-tetrahydrocannabinol (THC) using a battery of pain-stimulated, pain-depressed, and pain-independent behaviors in male and female mice. Intraperitoneal injection of dilute lactic acid (IP acid) served as an acute visceral noxious stimulus to stimulate two behaviors (stretching, facial grimace) and depress two behaviors (rearing, nesting). Nesting and locomotion were also assessed in the absence of IP acid as pain-independent behaviors. THC and a spectrum of six eCB catabolic enzyme inhibitors ranging from MAGL- to FAAH-selective were assessed for effectiveness to alleviate pain-related behaviors at doses that did not alter pain-independent behaviors. The MAGL-selective inhibitor MJN110 produced the most effective antinociceptive profile, with 1.0 mg/kg alleviating IP acid effects on stretching, grimace, and nesting without altering pain-independent behaviors. MJN110 effects on IP acid-depressed nesting had a slow onset and long duration (40 minutes to 6 hours), were blocked by rimonabant, and tended to be greater in females. As inhibitors increased in FAAH selectivity, antinociceptive effectiveness decreased. PF3845, the most FAAH-selective inhibitor, produced no antinociception up to doses that disrupted locomotion. THC decreased IP acid-stimulated stretching and grimace at doses that did not alter pain-independent behaviors; however, it did not alleviate IP acid-induced depression of rearing or nesting. These results support further consideration of MAGL-selective inhibitors as candidate analgesics for acute inflammatory pain. SIGNIFICANCE STATEMENT: This study characterized a spectrum of endocannabinoid catabolic enzyme inhibitors ranging in selectivity from monoacylglycerol lipase-selective to fatty acid amide hydrolase-selective in a battery of pain-stimulated, pain-depressed, and pain-independent behaviors previously pharmacologically characterized in a companion paper. This battery provides a method for prioritizing candidate analgesics by effectiveness to alleviate pain-related behaviors at doses that do not alter pain-independent behaviors, with inclusion of pain-depressed behaviors increasing translational validity and decreasing susceptibility to motor-depressant false positives.

Adverse effects of Δ9-tetrahydrocannabinol on neuronal bioenergetics during postnatal development.

Ongoing societal changes in views on the medical and recreational roles of cannabis increased the use of concentrated plant extracts with a Δ9-tetrahydrocannabinol (THC) content of more than 90%. Even though prenatal THC exposure is widely considered adverse for neuronal development, equivalent experimental data for young age cohorts are largely lacking. Here, we administered plant-derived THC (1 or 5 mg/kg) to mice daily during P5-P16 and P5-P35 and monitored its effects on hippocampal neuronal survival and specification by high-resolution imaging and iTRAQ proteomics, respectively. We found that THC indiscriminately affects pyramidal cells and both cannabinoid receptor 1+ (CB1R)+ and CB1R- interneurons by P16. THC particularly disrupted the expression of mitochondrial proteins (complexes I-IV), a change that had persisted even 4 months after the end of drug exposure. This was reflected by a THC-induced loss of membrane integrity occluding mitochondrial respiration and could be partially or completely rescued by pH stabilization, antioxidants, bypassed glycolysis, and targeting either mitochondrial soluble adenylyl cyclase or the mitochondrial voltage-dependent anion channel. Overall, THC exposure during infancy induces significant and long-lasting reorganization of neuronal circuits through mechanisms that, in large part, render cellular bioenergetics insufficient to sustain key developmental processes in otherwise healthy neurons.

Δ9-tetrahydrocannabinol: Drug discrimination abuse liability testing in female Lister Hooded rats: Trials, tribulations and triumphs.

INTRODUCTION: The assessment of the abuse potential of CNS-active drugs is a regulatory requirement. Drug discrimination is one of the nonclinical tests that contribute to this assessment by providing information on a drug's potential to induce a discriminative stimulus comparable to that of a known drug of abuse. AIM: The objective was to validate drug discrimination in the rat for the purpose of supporting regulatory submissions for novel drugs with potential cannabinoid-like activity. METHODS: Ten female Lister hooded rats were trained to discriminate no-drug from Δ9-THC (1.5 mg/kg, IP) under a FR10 schedule of reinforcement. Once trained, a Δ9-THC dose-response curve was obtained using doses of 0.25, 0.75, 1.5, and 3 mg/kg, IP. This was followed by evaluation of amphetamine (0.3 mg/kg, SC); morphine (3 mg/kg, IP); midazolam (2.5 mg/kg, PO); and the synthetic cannabinoids WIN55,212-2 (0.75 to 2 mg/kg, IP), CP-47,497 (0.5 to 2 mg/kg, IP), and JWH-018 (1 mg/kg, IP) for their discriminative stimulus similarity to Δ9-THC. RESULTS: Pharmacological specificity was demonstrated by achieving the anticipated dose-response curve for Δ9-THC, and a vehicle-like response for the non-cannabinoid drugs. Although full generalisation was obtained for JWH-018, in contrast to published literature, WIN55,212-2 and CP-47,497 failed to generalise to Δ9-THC. DISCUSSION: Based on the literature review performed in light of the results obtained, contrasting and unpredictable behavioural responses produced by cannabinoids in animals and humans raises the question of the reliability and relevance of including drug discrimination and self-administration studies within an abuse potential assessment for novel cannabinoid-like drugs.

Association of Naturalistic Administration of Cannabis Flower and Concentrates With Intoxication and Impairment.

Importance: The rapidly growing legal cannabis market includes new and highly potent products, the effects of which, to our knowledge, have not previously been examined in biobehavioral research studies because of federal restrictions on cannabis research. Objective: To use federally compatible, observational methods to study high-∆9-tetrahydrocannabinol (THC) legal market forms of cannabis. Design, Setting, and Participants: In this cohort study with a between-groups design that was conducted in a community and university setting, cannabis flower users and concentrate users were randomly assigned to higher- vs lower-THC products within user groups. Participants completed a baseline and an experimental mobile laboratory assessment that included 3 points: before, immediately after, and 1 hour after ad libitum legal market flower and concentrate use. Of the 133 individuals enrolled and assessed, 55 regular flower cannabis users (41.4%) and 66 regular concentrate cannabis users (49.6%) complied with the study's cannabis use instructions and had complete data across primary outcomes. Exposures: Flower users were randomly assigned to use either 16% or 24% THC flower and concentrate users were randomly assigned to use either 70% or 90% THC concentrate that they purchased from a dispensary. Main Outcomes and Measures: Primary outcome measures included plasma cannabinoids, subjective drug intoxication, and neurobehavioral tasks testing attention, memory, inhibitory control, and balance. Results: A total of 121 participants completed the study for analysis: 55 flower users (mean [SD] age, 28.8 [8.1] years; 25 women [46%]) and 66 concentrate users (mean [SD] age, 28.3 [10.4] years; 30 women [45%]). Concentrate users compared with flower users exhibited higher plasma THC levels and 11-hydroxyΔ9-THC (THC's active metabolite) across all points. After ad libitum cannabis administration, mean plasma THC levels were 0.32 (SE = 0.43) µg/mL in concentrate users (to convert to millimoles per liter, multiply by 3.18) and 0.14 (SE = 0.16) µg/mL in flower users. Most neurobehavioral measures were not altered by short-term cannabis consumption. However, delayed verbal memory (F1,203 = 32.31; P < .001) and balance function (F1,203 = 18.88; P < .001) were impaired after use. Differing outcomes for the type of product (flower vs concentrate) or potency within products were not observed. Conclusions and Relevance: This study provides information about the association of pharmacological and neurobehavioral outcomes with legal market cannabis. Short-term use of concentrates was associated with higher levels of THC exposure. Across forms of cannabis and potencies, users' domains of verbal memory and proprioception-focused postural stability were primarily associated with THC administration.

Herbal Preparations of Medical Cannabis: A Vademecum for Prescribing Doctors.

Cannabis has been used for centuries for therapeutic purposes. In the last century, the plant was demonized due to its high abuse liability and supposedly insufficient health benefits. However, recent decriminalization policies and new scientific evidence have increased the interest in cannabis therapeutic potential of cannabis and paved the way for the release of marketing authorizations for cannabis-based products. Although several synthetic and standardized products are currently available on the market, patients' preferences lean towards herbal preparations, because they are easy to handle and self-administer. A literature search was conducted on multidisciplinary research databases and international agencies or institutional websites. Despite the growing popularity of medical cannabis, little data is available on the chemical composition and preparation methods of medical cannabis extracts. The authors hereby report the most common cannabis preparations, presenting their medical indications, routes of administration and recommended dosages. A practical and helpful guide for prescribing doctors is provided, including suggested posology, titration strategies and cannabinoid amounts in herbal preparations obtained from different sources of medical cannabis.

Tetrahydrocannabinol and Cannabidiol Use in an Outpatient Palliative Medicine Population.

BACKGROUND: Palliative medicine physicians are challenged by lack of guidance regarding effectiveness and dosing of cannabis products in the setting of their emerging popularity. OBJECTIVE: The aim of this study was to describe early patterns of tetrahydrocannabinol (THC) and cannabidiol (CBD) use in Florida following passage of the state's first medical marijuana law. We describe here the perceived benefits, side effects, and beliefs expressed by patients in a single outpatient academic palliative medicine practice. METHODS: A cross-sectional survey was performed of a sequential convenience sample of patients who presented to an outpatient academic palliative medicine clinic over a 3-month period. RESULTS: In all, 24% (14/58) of respondents reported THC use, with half using THC on a daily basis. Patients reported improvements in pain, appetite, and nausea. In all, 71% (10/14) began using THC after the diagnosis of their chronic illness, and the most common form of usage was vaping. In all, 24% (14/58) of patients reported CBD use. Patients reported improvements in pain, and the most common form of usage was topical application. None of the patients had used CBD prior to the onset of their chronic illness. In all, 21% (3/14) of THC users and 21% (3/14) of CBD users thought that their substance was helping to cure their illness. Individual reported side effects in both groups were minimal. CONCLUSIONS: Approximately a quarter of outpatient palliative care patients use THC or CBD, often on a daily basis. Palliative care providers should be aware of the frequency, diverse usage, and beliefs behind cannabis product use in this patient population.

Cannabis for the Treatment of Crohn's Disease and Ulcerative Colitis: Evidence From Cochrane Reviews.

BACKGROUND: We systematically reviewed the safety and effectiveness of cannabis and cannabinoids treatment for Crohn's disease (CD) and ulcerative colitis (UC). METHODS: MEDLINE, Embase, WHO ICTRP, AMED, PsychINFO, CENTRAL, ClinicalTrials.Gov, and the European Clinical Trials Register were searched for relevant studies. MAIN RESULTS: Five randomized controlled trials (3 CD and 2 UC studies, 185 participants) were included. One CD study (N = 21) showed 45% (5 of 11) of the cannabis cigarette group experienced clinical remission compared with 10% (1 of 10) of the placebo group (risk ratio [RR] 4.55; 95% CI, 0.63-32.56). Another CD study (N = 19) did not show significant rates of clinical remission. Forty percent (4 of 10) of participants in the cannabis oil group experienced remission compared with 33% (3 of 9) of the placebo group (RR 1.20; 95% CI, 0.36-3.97). A UC study (N = 60) did not have significant clinical remission rates. Twenty-four percent (7 of 29) of cannabis oil participants experienced remission compared with 26% (8 of 31) of placebo participants (RR 0.94; 95% CI, 0.39-2.25). A second UC study (N = 32) showed the effects on disease activity, C-reactive protein levels, and fecal calprotectin levels were uncertain. Adverse events were more prevalent in the cannabis groups for both CD and UC studies. GRADE analysis for the UC and CD studies ranged from very low to moderate. CONCLUSIONS: In summary, no firm conclusions can be made regarding the safety and effectiveness of cannabis and cannabinoids in adults with CD and UC.

The effectiveness of self-directed medical cannabis treatment for pain.

The prior medical literature offers little guidance as to how pain relief and side effect manifestation may vary across commonly used and commercially available cannabis product types. We used the largest dataset in the United States of real-time responses to and side effect reporting from patient-directed cannabis consumption sessions for the treatment of pain under naturalistic conditions in order to identify how cannabis affects momentary pain intensity levels and which product characteristics are the best predictors of therapeutic pain relief. Between 06/06/2016 and 10/24/2018, 2987 people used the ReleafApp to record 20,513 cannabis administration measuring cannabis' effects on momentary pain intensity levels across five pain categories: musculoskeletal, gastrointestinal, nerve, headache-related, or non-specified pain. The average pain reduction was -3.10 points on a 0-10 visual analogue scale (SD = 2.16, d = 1.55, p < .001). Whole Cannabis flower was associated with greater pain relief than were other types of products, and higher tetrahydrocannabinol (THC) levels were the strongest predictors of analgesia and side effects prevalence across the five pain categories. In contrast, cannabidiol (CBD) levels generally were not associated with pain relief except for a negative association between CBD and relief from gastrointestinal and non-specified pain. These findings suggest benefits from patient-directed, cannabis therapy as a mid-level analgesic treatment; however, effectiveness and side effect manifestation vary with the characteristics of the product used.