Assessment Of Abuse Potential Research Articles

Assessment of pharmacological effects and abuse potential of 5F-EDMB-PICA, CUMYL-PEGACLONE, and NM-2201 in mice.

The newly emerging synthetic cannabinoids (SCs) 5F-EDMB-PICA, CUMYL-PEGACLONE, and NM-2201 have been observed to produce effects by activating cannabinoid type 1 (CB1) receptors. Nevertheless, the pharmacological effects and potential for abuse of these three substances remain to be studied. These substances have yet to be regulated in many countries. We investigated the safety, pharmacological effects, rewarding effects, and cannabinoid withdrawal of 5F-EDMB-PICA, CUMYL-PEGACLONE, and NM-2201. This study evaluated the drug safety and the cannabinoid-specific pharmacological effects of the three substances through acute toxicity experiments (in which the LD50 of each substance was obtained) and tetrad experiments (comprising assessments of hypothermia, analgesia, locomotion inhibition, and catalepsy). Furthermore, the conditioned place preference (CPP) experiments and withdrawal experiments were conducted to evaluate the rewarding effect and cannabinoid withdrawal potential of the substances in question. The results demonstrated that all three drugs exhibited certain acute toxic effects and could potentially induce tetrad effects. The data were analyzed using non-linear regression, and the corresponding ED50 values and 95% confidence intervals (CI) were obtained. The rank order of potency was determined to be CUMYL-PEGACLONE > 5F-EDMB-PICA > NM-2201. In the CPP experiments, it was demonstrated that 5F-EDMB-PICA significantly induced an increase in CPP score at a dose of 0.3mg/kg, while NM-2201 caused an increase in CPP score and a significant aversion effect at a dose of 2 and 3mg/kg, respectively. It is noteworthy that all three types of SCs were observed to produce a significant biphasic effect, indicating that CPP scores were biphasic for all compounds. Following the administration of the CB1 receptor antagonist rimonabant, a notable increase in head twitches and paw tremors was observed, indicating that these three SCs induce cannabinoid withdrawal through the mediation of CB1 receptors. The results of this study indicated that these SCs possess cannabinoid-specific pharmacological effects and abuse potential, which provides substantial experimental data to support the future regulation of these substances.

Assessment of human abuse potential of an unflavored, sucralose-sweetened electronic cigarette in combustible cigarette smokers.

Despite the popularity of electronic cigarettes (ECIGs), limited research has examined the role of sweeteners, independent of other flavors, in shaping ECIG human abuse potential (HAP). This study examined the effects of sucralose and nicotine in unflavored ECIG liquid solutions to provide a basic understanding of the effects of sweeteners on ECIG HAP compared to combustible cigarettes. Individuals who smoked cigarettes daily (N = 14) completed five within-subject, Latin-square ordered study sessions that differed by product used: (a) own-brand combustible cigarettes (OB), (b) 0 mg/mL nicotine, unsweetened liquid, (c) 0 mg/mL nicotine, sucralose-sweetened liquid, (d) 15 mg/mL nicotine, unsweetened liquid, and (e) 15 mg/mL nicotine, sucralose-sweetened liquid. Participants completed subjective questionnaires and behavioral tasks following a 10-puff directed use bout during which puff topography was measured, and blood was sampled for later measurement of plasma nicotine concentration. On average, the OB condition had a greater increase in plasma nicotine concentration and produced more pronounced subjective effects compared to the ECIG conditions. The 15 mg/mL nicotine ECIGs delivered significantly more nicotine and produced greater drug effects and reductions in tobacco abstinence symptoms than the 0 mg/mL nicotine ECIGs. Sucralose-containing solutions increased ECIG product appeal, puff duration, and puff volume during the 10-puff directed bout. Findings revealed greater HAP for OB cigarettes relative to all ECIGs tested and suggest that adding sucralose and nicotine elevates ECIG HAP via different mechanisms; sucralose appears to influence HAP through product appeal, while nicotine influences HAP through drug effects and tobacco/nicotine abstinence symptom suppression. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Preclinical evaluation of abuse potential of the peripherally-restricted kappa opioid receptor agonist HSK21542

HSK21542 is a peripherally-restricted kappa opioid receptor (KOR) agonist developed for pain treatment. Because of the CNS pharmacological concern of opioid receptor activation, such as physical dependence and addiction potential, an assessment of abuse potential of HSK21542 was required prior to marketing approval. The preclinical abuse potential assessments for HSK21542 included the following studies: 1) intravenous self-administration study to explore the relative reinforcing efficacy in rats self-administering remifentanil; 2) rat drug discrimination study to examine the pharmacological similarity of the interoceptive or subjective effects of HSK21542 in rats discriminating pentazocine; 3) rat conditioned place preference (CPP) paradigm to test the rewarding effects; 4) rat natural physical dependence-spontaneous withdrawal study in rats chronically treated with HSK21542; 5) naloxone-precipitated withdrawal assay following chronic HSK21542 exposure to evaluate its physical dependence potential. The results showed that HSK21542 was devoid of behavioral evidence of positive reinforcing effect and did not share similar discriminative stimulus effects with pentazocine. HSK21542 also did not produce CPP in rats. In addition, HSK21542 did not produce spontaneous withdrawal or naloxone-precipitated withdrawal in rats with chronic treatments. Collectively, these preclinical findings suggest that HSK21542 has no abuse potential in animals, which demonstrate low abuse potential in humans.

S158 - Psychedelic Drug Abuse Potential Assessment Challenges to Scientific Validity and Real World Predictiveness: Current Approaches and Research Gaps

S158 - Psychedelic Drug Abuse Potential Assessment Challenges to Scientific Validity and Real World Predictiveness: Current Approaches and Research Gaps

Abuse potential assessment of the dual orexin receptor antagonist daridorexant in rats.

Drugs that act on the central nervous system (CNS) and have sedative effects can lead to abuse in humans. New CNS-active drugs often require evaluation of their abuse potential in dedicated animal models before marketing approval. Daridorexant is a new dual orexin receptor antagonist (DORA) with sleep-promoting properties in animals and humans. It was approved in 2022 in the United States and Europe for the treatment of insomnia disorder. Nonclinical evaluation of abuse potential of daridorexant using three specific rat models assessing reinforcement, interoception, and withdrawal. Reinforcing effects of daridorexant were assessed in an operant rat model of intravenous drug self-administration. Similarity of interoceptive effects to those of the commonly used sleep medication zolpidem was tested in an operant drug discrimination task. Withdrawal signs indicative of physical dependence were evaluated upon sudden termination of chronic daridorexant treatment. Rat experiments were conducted at a dose range resulting in daridorexant plasma concentrations equaling or exceeding those achieved at the clinically recommended dose of 50 mg in humans. Daridorexant had no reinforcing effects, was dissimilar to zolpidem in the drug discrimination task, and did not induce any withdrawal-related signs upon treatment discontinuation that would be indicative of physical dependence. Daridorexant showed no signs of abuse or dependence potential in rats. Our data indicate that daridorexant, like other DORAs, has a low potential for abuse in humans.

Failure of the dual orexin receptor antagonist suvorexant to engender drug discrimination in rats.

For abuse potential assessment, U.S. Food and Drug Administration (FDA) requests that new, brain-penetrating drugs are ideally compared with approved drugs that share the mechanism of action and are judged to have abuse liability by the Drug Enforcement Agency. For development of the dual orexin receptor antagonist (DORA) daridorexant, the FDA recommended conducting a rat drug discrimination paradigm against the approved, schedule IV, DORA suvorexant. Surprisingly, at suvorexant plasma levels up to three-fold the maximum concentration at the highest approved human dose, rats did not learn to discriminate the suvorexant stimulus from vehicle.

Assessment of abuse potential of carfentanil.

Carfentanil, as a fentanyl analogue, is a potent synthetic opioid. It has been controlled in many countries, and its emergence has been highlighted by many recent reports. However, although discriminative stimulus effects of carfentanil in rats had been reported, its abuse potential has not been fully evaluated. In this study, we evaluated the abuse potential of carfentanil via the tests of conditioned place preference (CPP), drug self-administration and naloxone-precipitated opioid withdrawal assay, compared with fentanyl and heroin. Carfentanil exhibited significant place preference at a minimum dose of 1μg/kg in mice, whereas fentanyl and heroin induced significant place preference at the minimum doses of 100 μg/kg and 1000 μg/kg, respectively. In the drug-substitution test in heroin self-administered rats (50 μg/kg/infusion), carfentanil and fentanyl acquired significant self-administrations above saline levels from 0.05-0.1 and 0.1-10.0μg/kg/infusion, respectively. Carfentanil induced the maximum number of infusions at 0.1μg/kg, whereas fentanyl and heroin at 1 and 25 μg/kg, respectively. In short, carfentanil showed the highest potency to induce CPP and self-administration. Furthermore, repeated treatment with escalating doses of carfentanil, fentanyl or heroin induced typical withdrawal symptoms in mice, including a greater number of jumping and weight loss than saline group. This indicated that carfentanil could produce physical dependence similar to fentanyl and heroin. Taken together, the present study demonstrated the higher abuse potential of carfentanil compared with fentanyl and heroin. The rank order of abuse potential for these compounds is carfentanil > fentanyl > heroin.

Psychedelic drug abuse potential assessment for new drug applications and controlled substance scheduling: A United States perspective

Psychedelics are an increasingly active area of research and pharmaceutical development. This includes abuse potential assessment to better understand their pharmacological mechanisms and effects and guide controlled substance regulation. Psychedelics pose challenges to abuse assessments to ensure valid, reliable, and generalizable outcomes and safe study conduct. Key nonclinical techniques, for example, receptor binding and functional assays in vitro, and nonclinical physical dependence determinations, are easily adaptable to psychedelics. However, the entactogens (weak reinforcers) and hallucinogens (non-reinforcers) require more flexible approaches than typically recommended by regulatory agencies. Phase 1 pharmacokinetic/pharmacodynamic safety studies and Phases 2/3 efficacy/safety trials with systematic monitoring of abuse-related adverse events are readily applicable to psychedelics. Human abuse trials require modification because supratherapeutic doses may not be safe and procedures, for example, personal monitors to manage serious adverse events, might bias outcomes. Abuse-related studies for psychedelics requiring approval by Food and Drug Administration and other agencies should take into consideration existing knowledge that will vary from extensive, for example, psilocybin, to zero for novel hallucinogens and entactogens. Many abuse assessments can be reasonably applied to animals and humans without compromising scientific integrity. Modification of existing techniques and incorporating a broader range of nonclinical tests should ensure generalizable outcomes. Human abuse studies merit reconsideration and possible modification to ensure safety and validity for psychedelic drug evaluation. Other nonclinical and clinical methods can provide evaluations of the pharmacological equivalence of test drugs to known drugs of abuse to provide context to the abuse assessment and guide drug scheduling.

Opioid-like adverse effects of tianeptine in male rats and mice.

Tianeptine is a mu-opioid receptor (MOR) agonist with increasing reports of abuse in human populations. Preclinical data regarding the abuse potential and other opioid-like adverse effects of tianeptine at supratherapeutic doses are sparse. The present study evaluated tianeptine in a rat model of abuse potential assessment and in mouse models of motor, gastrointestinal, and respiratory adverse effects. Abuse potential was assessed in adult male Sprague-Dawley rats using an intracranial self-stimulation (ICSS) procedure to determine effects of acute and repeated tianeptine on responding for electrical brain stimulation. Male ICR mice were used to determine the effects of tianeptine in assays of locomotor behavior and gastrointestinal motility. Male Swiss-Webster mice were monitored for respiratory changes using whole-body plethysmography. In rats, acute tianeptine produced weak and delayed evidence for abuse-related ICSS facilitation at an intermediate dose (10mg/kg, IP) and pronounced, naltrexone-preventable ICSS depression at a higher dose (32mg/kg, IP). Repeated 7-day tianeptine (10 and 32mg/kg/day, IP) produced no increase in abuse-related ICSS facilitation, only modest tolerance to ICSS depression, and no evidence of physical dependence. In mice, tianeptine produced dose-dependent, naltrexone-preventable locomotor activation. Tianeptine (100mg/kg, SC) also significantly inhibited gastrointestinal motility and produced naloxone-reversible respiratory depression. Tianeptine presents as a MOR agonist with resistance to tolerance and dependence in our ICSS assay in rats, and it has lower abuse potential by this metric than many commonly abused opioids. Nonetheless, tianeptine produces MOR agonist-like acute adverse effects that include motor impairment, constipation, and respiratory depression.

Kratom Abuse Potential 2021: An Updated Eight Factor Analysis.

Drugs are regulated in the United States (US) by the Controlled Substances Act (CSA) if assessment of their abuse potential, including public health risks, show such control is warranted. An evaluation via the 8 factors of the CSA provides the comprehensive assessment required for permanent listing of new chemical entities and previously uncontrolled substances. Such an assessment was published for two kratom alkaloids in 2018 that the Food and Drug Administration (FDA) have identified as candidates for CSA listing: mitragynine (MG) and 7-hydroxymitragynine (7-OH-MG) (Henningfield et al., 2018a). That assessment concluded the abuse potential of MG was within the range of many other uncontrolled substances, that there was not evidence of an imminent risk to public health, and that a Schedule I listing (the only option for substances that are not FDA approved for therapeutic use such as kratom) carried public health risks including drug overdoses by people using kratom to abstain from opioids. The purpose of this review is to provide an updated abuse potential assessment reviewing greater than 100 studies published since January 1, 2018. These include studies of abuse potential and physical dependence/withdrawal in animals; in-vitro receptor binding; assessments of potential efficacy treating pain and substance use disorders; pharmacokinetic/pharmacodynamic studies with safety-related findings; clinical studies of long-term users with various physiological endpoints; and surveys of patterns and reasons for use and associated effects including dependence and withdrawal. Findings from these studies suggest that public health is better served by assuring continued access to kratom products by consumers and researchers. Currently, Kratom alkaloids and derivatives are in development as safer and/or more effective medicines for treating pain, substances use disorders, and mood disorders. Placing kratom in the CSA via scheduling would criminalize consumers and possession, seriously impede research, and can be predicted to have serious adverse public health consequences, including potentially thousands of drug overdose deaths. Therefore, CSA listing is not recommended. Regulation to minimize risks of contaminated, adulterated, and inappropriately marketed products is recommended.

Abuse potential assessment of the new dual orexin receptor antagonist daridorexant in recreational sedative drug users as compared to suvorexant and zolpidem.

Abuse potential properties have been reported for the dual orexin receptor antagonists (DORAs) suvorexant and lemborexant. Daridorexant is a new DORA currently in late-stage clinical development. This randomized, double-blind, double-dummy, placebo- and active-controlled six-period crossover study assessed its abuse potential in healthy recreational sedative drug users (n = 63). In each study period, a single, oral, morning dose of either daridorexant (50, 100, and 150 mg), placebo, or active control, i.e. suvorexant (150 mg) or zolpidem (30 mg), was administered. Primary pharmacodynamic (PD) endpoint was the Emax of the drug-liking visual analog scale (VAS) assessed over 24 h. Several secondary subjective and objective PD endpoints were also assessed. Study validity was confirmed based on drug-liking of suvorexant and zolpidem greater than placebo applying a predefined 15-point validity margin (p < 0.0001). Drug-liking VAS Emax (mean; 95% confidence interval) of daridorexant at 50 mg (73.2; 69.0-77.5) was significantly lower compared to suvorexant (80.7; 77.0-84.5) and zolpidem (79.9; 76.2-83.5) (p < 0.001), but similar at 100 mg (79.1; 75.0-83.3) and 150 mg (81.3; 77.7, 84.8). Such dose-related patterns were also observed for most secondary endpoints. At each daridorexant dose, Drug-liking VAS scores were greater than placebo. Both control drugs and daridorexant were safe and the pharmacokinetics of daridorexant was consistent with earlier trials indicating quick absorption and elimination. In this large, valid human abuse potential study, daridorexant showed dose-related drug-liking among recreational sedative drug users with lower effects at the highest phase-3 dose, and similar effects at higher doses compared to supratherapeutic doses of suvorexant and zolpidem. Study to Evaluate the Abuse Potential of ACT-541468 in Healthy Recreational Drug Users, https://www.clinicaltrials.gov/ct2/show/NCT03657355?term=ACT-541468&draw=3&rank=18, NCT03657355.

Rate of Onset as a Determinant of Abuse Potential Assessment Using Intracranial Self‐Stimulation in Rats

Background Intracranial self-stimulation (ICSS) is one procedure that has been used to evaluate abuse potential of drugs, and as with more commonly used drug self-administration procedures, ICSS is especially sensitive to drugs that activate the mesolimbic dopamine system. Drug self-administration studies have shown that abuse potential can also be influenced by temporal parameters, and especially rate of onset; however, the degree to which rate of onset influences abuse-potential metrics in ICSS procedures has not been systematically examined. To address this issue, this study evaluated three dopamine transporter (DAT) inhibitors that have different onset rates and were shown previously to maintain different peak break points in rhesus monkeys responding under a progressive-ratio schedule (cocaine > WIN35428 > RTI-31 for both rate of onset and break point). In ICSS, abuse potential is generally indicated when a drug increases low rates of responding maintained by low levels of brain stimulation, a phenomenon called “ICSS facilitation”. We hypothesized that these three DAT inhibitors would facilitate ICSS different time courses, but the degree to which rate of onset might influence peak facilitation was unknown. Methods Adult male and female Sprague-Dawley rats (n = 5-7 per drug) were surgically implanted with permanent stainless-steel electrodes targeting the medial forebrain bundle and trained to respond on a lever to receive electrical brain stimulation. Behavioral sessions were organized in components consisting of ten one-minute frequency trials over a range of brain-stimulation frequencies (56-158 Hz), such that a full curve relating brain-stimulation frequency to response rate could be determined every 10 min. On test days, three baseline ICSS components were followed first by intraperitoneal drug injection and then immediately by 12 consecutive test components (120 min). Additional pairs of test components were initiated at 300 and 1440 minutes post-injection. The drugs and dose ranges tested were as follows: cocaine HCl (1.0 - 10 mg/kg), WIN35428 (0.10 – 0.32 mg/kg), and RTI-31 (0.032 – 0.10 mg/kg). All drugs were tested up to doses that produced peak levels of ICSS facilitation; higher doses disrupted responding and produced stereotypies. Results Under baseline conditions, brain stimulation maintained a frequency-dependent increase in reinforcement rates. All three drugs dose-dependently and robustly facilitated ICSS, shifting ICSS frequency-rate curves to the left and increasing the total number of stimulations per component when data were collapsed across all frequencies. Consistent with previous studies, the rate of onset for ICSS facilitation was fastest for cocaine, slower for WIN35428, and slowest for RTI-31. Cocaine also had the shortest duration of action and the lowest potency, whereas RTI-31 had the longest duration of action and highest potency. However, despite these differences in time course and potency, peak ICSS facilitation was not statistically different across drugs. Conclusions These results suggest that ICSS studies should evaluate rate of onset as well as peak ICSS facilitation in reaching conclusions about overall abuse potential of a test drug.

P.031 Abuse potential assessment of the novel dual orexin receptor antagonist daridorexant compared to suvorexant and zolpidem in recreational drug users

P.031 Abuse potential assessment of the novel dual orexin receptor antagonist daridorexant compared to suvorexant and zolpidem in recreational drug users

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

IntroductionThe 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. AimThe objective was to validate drug discrimination in the rat for the purpose of supporting regulatory submissions for novel drugs with potential cannabinoid-like activity. MethodsTen 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. ResultsPharmacological 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. DiscussionBased 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.

Development of quantitative biomarkers of drug-induced activation of the reward system for abuse potential assessment

Development of quantitative biomarkers of drug-induced activation of the reward system for abuse potential assessment

Preclinical assessment of tramadol abuse potential: Effects of acute and repeated tramadol on intracranial self-stimulation in rats.

Tramadol is a widely used analgesic that activates mu-opioid receptors (MOR) and inhibits serotonin and norepinephrine transporters. This mixed pharmacology may limit both its own abuse potential and its modulation of abuse potential of other MOR agonists. This study used an intracranial self-stimulation (ICSS) procedure to compare abuse-related effects produced by acute or repeated treatment with tramadol or morphine in rats. Abuse potential in ICSS procedures is indicated by a drug-induced increase (or 'facilitation') of ICSS responding. Adult male Sprague-Dawley rats were implanted with electrodes targeting the medial forebrain bundle and trained to respond on a lever for pulses of electrical brain stimulation. Tramadol effects were evaluated after acute administration (3.2-32 mg/kg) in the absence or presence of the opioid antagonist naltrexone, the CYP2D6 hepatic-enzyme inhibitor quinine or a combination of both. Additionally, both tramadol and morphine were also tested before and after repeated tramadol (32 mg/kg/day for six days) or repeated morphine (3.2 mg/kg/day for six days). Acute tramadol produced primarily ICSS rate-decreasing effects that were antagonised by naltrexone but not by quinine or naltrexone + quinine. Tramadol also produced little or no ICSS facilitation after repeated tramadol or repeated morphine, and repeated tramadol did not enhance ICSS facilitation by morphine. By contrast, morphine-induced ICSS facilitation was enhanced by repeated morphine treatment. These results suggest that tramadol has lower abuse potential than other abused MOR agonists and that repeated tramadol exposure produces relatively little enhancement of abuse potential of other MOR agonists.

An Assessment of Fathers Child Abuse Potential in Terms of Their History of Being Maltreated by Their Fathers

An Assessment of Fathers Child Abuse Potential in Terms of Their History of Being Maltreated by Their Fathers

Childhood adversity and parenting behavior: the role of oxytocin receptor gene polymorphisms.

Previous research revealed experiences of childhood adversity (CA) to be related to less favorable parenting behavior. It can further be expected that maternal oxytocin receptor (OXTR) genes may influence parenting behavior and moderate relationships between CA and parenting behavior. Moreover, associations between the OXTR gene and plasma oxytocin (OT) have been discussed. The present study investigated main effects of the OXTR gene on parenting behavior and plasma OT of mothers, and moderating effects of the OXTR gene on the relationship between mothers' experiences of CA and parenting behavior. We relied on a sample of 193 mothers and their on average 8-year-old children. Maternal experiences of CA were assessed using a standardized interview. A questionnaire for the assessment of child abuse potential and observations of mother-child interaction were used as indicators of parenting behavior. For mothers, we analyzed three polymorphisms (rs53576, rs1042778, rs2254298) of the OXTR gene and plasma OT. Only the rs53576 was associated with mothers' parenting behavior, specifically with maternal sensitivity. The rs2254298 significantly moderated relations between mothers' experiences of CA and parenting behavior. Significant relations could be found only for mothers who were homozygous for the G allele. The G allele of the rs2254298 was further related to increased plasma OT levels. Our findings underline the importance of considering genetic variation when investigating consequences of CA and developing intervention programs that are adapted to an individual's needs.

Abuse potential assessment of cannabidiol (CBD) in recreational polydrug users: A randomized, double-blind, controlled trial

RationaleTreatment with a highly purified oral solution of cannabidiol (CBD), derived from the plant Cannabis sativa L., demonstrated some evidence of central nervous system (CNS)-related adverse events in patients enrolled in phase 3 trials for treatment of childhood-onset epilepsy. Cannabidiol was categorized as a Schedule 1 substance by the United States Drug Enforcement Administration; therefore, it was important to test CBD for human abuse potential. MethodsThis was a single-dose, randomized, double-blind, double-dummy, placebo- and active-controlled crossover trial. The abuse potential of single oral doses of plant-derived pharmaceutical formulations of highly purified CBD (Epidiolex®; 750 mg, 1500 mg, and 4500 mg) was compared with that of single oral doses of alprazolam (2 mg), dronabinol (10 mg and 30 mg), and placebo in healthy recreational polydrug users. The primary endpoint to assess abuse potential was the maximum effect (Emax) on Drug-Liking visual analog scale (VAS). Other measurements included Emax on Overall Drug-Liking VAS, Take Drug Again VAS, positive and negative effects, other subjective effects, and Drug Similarity VAS. Cognitive and psychomotor functions were assessed using the Divided Attention Test, the Hopkins Verbal Learning Test—Revised, and the Digit–Symbol Substitution Task. Pharmacokinetic parameters were determined for CBD and its major metabolites. Standard safety measures and adverse events were assessed. Principal resultsOf 95 eligible subjects, 43 qualified for the treatment phase, received at least 1 dose of investigational medicinal product, and were included in safety assessments; 35 subjects were included in the pharmacodynamic analysis. Subjects receiving alprazolam and dronabinol had significantly higher Drug-Liking Emax (P < 0.0001) compared with those receiving placebo, confirming study validity. Compared with placebo, Drug-Liking was not significantly different for subjects taking 750-mg CBD (P = 0.51). Drug-Liking Emax values for 1500-mg and 4500-mg CBD were significantly different from placebo (P = 0.04 and 0.002, respectively); however, the mean differences were <10 points on VAS compared with >18-point differences between positive controls and placebo. Alprazolam and dronabinol had significantly higher Drug-Liking, Overall-Liking, and Take Drug Again VAS Emax values compared with all doses of CBD (P ≤ 0.004). In contrast to alprazolam, CBD administration had no observable effect on cognitive/psychomotor tests. Pharmacokinetic parameters for CBD in this trial were consistent with previous studies. The majority of adverse events reported during the trial were of mild or moderate severity; no serious adverse events or deaths were reported. ConclusionAdministration of a therapeutic dose of CBD (750 mg) showed significantly low abuse potential in a highly sensitive population of polydrug users. Although high and supratherapeutic doses of CBD (1500 mg and 4500 mg, respectively) had detectable subjective effects compared with placebo; the effects were significantly lower than those observed with alprazolam and dronabinol.

Book Review: Nonclinical Assessment of Abuse Potential for New Pharmaceuticals—1st Edition

Book Review: Nonclinical Assessment of Abuse Potential for New Pharmaceuticals—1st Edition