Search

Beatrice Setnik,1 Carl L Roland,1 Kenneth W Sommerville,1,2 Glenn C Pixton,1 Robert Berke,3,4 Anne Calkins,5 Veeraindar Goli1,2 1Pfizer Inc, 2Duke University Medical Center, Durham, NC, 3Family Health Medical Services PLLC, Mayville, NY, 4Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, NY, 5New York Spine & Wellness Center, Syracuse, NY, USA Objective: To compare the investigator assessment of patient risk for prescription opioid misuse, abuse, and diversion with patient self-reports of these activities in a population with chronic pain. Methods: As a secondary objective of an open-label, multicenter, primary care-based clinical study to evaluate the success of converting opioid-experienced patients with chronic pain to morphine sulfate with sequestered naltrexone hydrochloride, risk for misuse, abuse, and diversion was assessed using two nonvalidated questionnaires: one was completed by the investigator and another by the patient (Self-Reported Misuse, Abuse, and Diversion [SR-MAD]). In addition, the validated Current Opioid Misuse Measure (COMM) test and urine drug test were used. Results: Of the 684 patients assessed by the investigators, 537 returned the self-assessment, SR-MAD. Most patients were assigned by the investigator as low risk for misuse (84.2%), abuse (89.3%), and diversion (94.3%). Of the patients who returned SR-MAD, 60% indicated having taken more opioids than prescribed and 10.9% reported chewing or crushing their opioids in the past. Of the patients who completed COMM, 40.6% were deemed as having aberrant behaviors. COMM results correlated with the risk levels from the investigator assessment. One-third of patients (33.8%) had at least one abnormal urine drug test result. Conclusion: More research is needed to better understand the gap between the investigator assessment of potential risk for misuse, abuse, and diversion and the actual extent of these behaviors among patients with chronic pain. Keywords: opioid, abuse, misuse, diversion, chronic pain

Beatrice Setnik,1 Carl L Roland,1 Kenneth W Sommerville,1,2 Glenn C Pixton,1 Robert Berke,3,4 Anne Calkins,5 Veeraindar Goli1,2 1Pfizer Inc, 2Duke University Medical Center, Durham, NC, USA; 3Family Health Medical Services PLLC, Mayville, 4Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, 5New York Spine & Wellness Center, Syracuse, NY, USA Objective: To evaluate the conversion of opioid-experienced patients with chronic moderate-to-severe pain to extended-release morphine sulfate with sequestered naltrexone hydrochloride (MSN) using a standardized conversion guide. Methods: This open-label, single-arm study was conducted in 157 primary care centers in the United States. A total of 684 opioid-experienced adults with chronic moderate-to-severe pain were converted to oral administration of MSN from transdermal fentanyl and oral formulations of hydrocodone, hydromorphone, methadone, oxycodone, oxymorphone, and other morphine products using a standardized conversion guide. The primary endpoint was the percentage of patients achieving a stable MSN dose within a 6-week titration phase. Secondary endpoints included duration of time to stable dose, number of titration steps, safety and efficacy measures, and investigator assessment of conversion guide utility. Results: Of the 684 patients, 51.3% were converted to a stable dose of MSN (95% confidence interval: 47.5%, 55.1%). The mean (standard deviation) number of days to stable dose was 20 (8.94), and number of titration steps to stable dose was 2.4 (1.37). The majority of adverse events were mild/moderate and consistent with opioid therapy. Mean pain scores at stable dose decreased from baseline. Investigators were generally satisfied with the conversion guide and, in 94% of cases, reported they would use it again. Conclusion: Conversion to MSN treatment using the standardized MSN conversion guide was an attainable goal in approximately half of the population of opioid-experienced patients with chronic moderate-to-severe pain. Investigators found the guide to be a useful tool to assist conversion of opioid-experienced patients to MSN. Keywords: opioid conversion, rotation, morphine, primary care, safety, equianalgesic

James Brown1, Beatrice Setnik2, Keung Lee3, Jody M Cleveland2, Carl L Roland2, Linda Wase4, Lynn Webster5 1Jena Medical, Ormond Beach, FL; 2Pfizer Inc, Cary, NC; 3Randolph Medical Associates, Asheboro, NC; 4Archimedes Pharma US Inc, Bedminster, NJ; 5Lifetree Clinical Research, Salt Lake City, UT, USA Background: The purpose of this study was to determine the effectiveness and safety of morphine sulfate extended-release capsules among primary care patients with chronic, moderate-to-severe pain using a universal precautions approach that assessed and monitored risk for opioid misuse and abuse. Methods: This open-label, uncontrolled, multicenter, prospective study was conducted in primary care centers (n = 281) and included opioid-naïve and opioid-experienced patients with either a pain score ≥4 (0 = no pain, 10 = pain as bad as you can imagine), or with unacceptable side effects while taking opioids. The patients were treated with morphine sulfate extended-release capsules for up to four months. Patient-rated pain intensity (worst, least, average) over the past 24 hours (0–10 scale), pain interference with seven activities of daily living (0 = no interference, 10 = completely interferes), and adverse events were recorded. Results: Of 1487 patients who filled at least one prescription, 561 (38%) completed the study. Patients were primarily white (87%) and female (57%); 92% had pain for more than one year; and 79% were opioid-experienced. Median age was 52 years. Decreases in mean (± standard deviation) average pain scores (baseline 6.2 ± 2.3) were -0.8 ± 2.2 at visit 2 (5–14 days later), and -1.6 ± 2.3 and -1.7 ± 2.2 at visits 3 and 4 (spaced 3–4 weeks apart), respectively, and -1.1 ± 2.4 at visit 5 (included patients withdrawn from the study who were no longer taking the study drug). A similar trend was observed for worst pain and least pain scores and for pain interference with activities. Fifty-one percent of the safety population patients and 81% in the completer population reported being satisfied or very satisfied with the study treatment. Most common adverse events were typical of opioids, ie, constipation (14%), nausea (11%), vomiting (5%), and somnolence (5%). Conclusion: The results suggest that pain outcomes improved in patients with chronic, moderate-to-severe pain receiving morphine sulfate extended-release capsules within the context of a structured universal precautions approach in the primary care setting. Keywords: opioids, analgesics, primary care, pain assessment, substance abuse, universal precautions

Abstract: The potential effect of ethanol to accelerate drug release from sustained release (SR) oral formulations is a general concern. Marketed Verapamil is a calcium channel blocker, mainly used as antihypertensive and anti-anginal drug and available in various dose and dosage forms. One is Verapamil Meltrex®, combining an innovative and unique SR formulation and technology that achieves a stable solid dispersion of drug by using melt extrusion technology. The aim of this investigation was to determine the influence of ethanol on the in vitro rate of release of marketed Verapamil (240mg) Meltrex®, in contrast to three compressed marketed Verapamil (240mg) SR formulations. Dissolution was tested under standardized conditions, with mediums containing ethanol concentrations of 0, 5, 20, and 40%. The dissolution profiles for Verapamil Meltrex® showed no differences between 5 and 40% ethanol versus 0% ethanol (P >0.05). The mean dissolution percentage (%) was identical at 1h (19%) in 0% versus 40% ethanol. In contrast, the three comparators showed significant increases in dissolution in 20 and 40% ethanol versus 0% ethanol (P <0.001). An initial rapid release (within 2h) was observed in 20 and 40% ethanol, with a mean dissolution of 99% (range 73–107%). Therefore, unlike the three SR Verapamil formulations tested, Verapamil Meltrex® was found to be resistant to in vitro dose dumping when combined with readily accessible ethanol concentrations. [Copyright &y& Elsevier]

Rationale: Lemborexant (LEM) is a dual orexin receptor antagonist (DORA) approved in multiple countries including the USA, Japan, Canada, Australia, and several Asian countries for the treatment of insomnia in adults. As a compound with central nervous system activity, it is important to understand the abuse potential of LEM with respect to public health., Objectives: This review discusses data for LEM relevant to each of the 8 factors of the United States Controlled Substances Act., Results: LEM did not demonstrate abuse potential in nonclinical testing and was associated with a low incidence of abuse-related adverse events in clinical study participants with insomnia disorder. Similar to other DORAs that have been evaluated (eg., almorexant, suvorexant (SUV), and daridorexant), LEM and the positive controls (zolpidem and SUV) also showed drug liking in a phase 1 abuse potential study that enrolled subjects who used sedatives recreationally. However, internet surveillance of SUV and the FDA Adverse Events Reporting System suggests that drugs in the DORA class display very low abuse-related risks in the community. Additionally, as described in FDA-approved labeling, it does not carry physical dependence and withdrawal risks., Conclusions: LEM, similar to most other prescription insomnia medications, was placed into Schedule IV. However, LEM and other drugs in the DORA class may have a lower potential for abuse as suggested by real-world postmarketing data from federal surveys and internet surveillance, and thus may have lower risks to public health than Schedule IV benzodiazepines and nonbenzodiazepine hypnotics that potentiate GABA signaling., (© 2023. The Author(s).)

Background: Lemborexant (LEM) is a dual orexin receptor antagonist approved for the treatment of insomnia in adults in multiple countries including the the United States, Japan, Canada, Australia and several Asian countries., Procedures: This was a randomized, single-dose, single-center, double-blind, active-control, 6-way crossover study to evaluate LEM abuse potential. The study assessed oral doses of LEM 10 mg (LEM10), 20 mg (LEM20), and 30 mg (LEM30) compared with placebo (PBO), zolpidem (ZOL) immediate release 30 mg, and suvorexant (SUV) 40 mg. Subjects were healthy, nondependent, recreational sedative users able to discriminate/like the effects of both SUV and ZOL from PBO during a qualification phase., Results: Abuse potential endpoints were analyzed in qualified subjects who received and completed all treatments (n = 32). On the "at this moment" drug-liking visual analog scale (VAS), mean maximum (peak) effect (primary endpoint) values were 78.4, 80.5, and 83.6 for LEM10, LEM20, and LEM30, respectively, which were all significantly greater than PBO (57.8; all P > 0.05) but not different from SUV (76.1) or ZOL (78.3). Similarly, for secondary endpoints overall drug-liking VAS and take-drug-again VAS, mean maximum (peak) effect values for all LEM doses were significantly greater than PBO ( P > 0.05) but not different compared with ZOL or SUV., Conclusions: For all doses, LEM demonstrated abuse potential versus PBO and appeared to have a similar abuse potential profile to ZOL and SUV in this study population. Lemborexant was well tolerated. Lemborexant has been placed in Schedule IV, the same drug schedule as ZOL and SUV., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose/background: As part of a human abuse potential (HAP) study of lemborexant (LEM), the effects of therapeutic (LEM 10 mg), and supratherapeutic doses of LEM 20 mg and LEM 30 mg on cognition and psychomotor performance were compared with placebo (PBO) and supratherapeutic doses of zolpidem (ZOL) 30 mg and suvorexant (SUV) 40 mg. Subjects (n = 32) were healthy, nondependent, recreational sedative users able to discriminate the effects of both SUV and ZOL from PBO on subjective drug measures., Methods/procedures: The human abuse potential study was a single-dose, randomized, double-blind, PBO-controlled, 6-way crossover study. Eligible subjects admitted to the treatment phase completed the choice reaction test (CRT) and divided attention test. The CRT included measurements of recognition reaction time (RRT) and motor reaction time., Findings/results: Recognition reaction time and mean maximum change from baseline (CFB max ) scores were significantly increased (slower performance) versus PBO for all LEM doses (all P < 0.001), ZOL ( P < 0.001), and SUV ( P = 0.004), and LEM (all doses) was not statistically different from ZOL or SUV. Motor reaction time and mean CFB max versus PBO were significantly increased for all LEM doses (all P < 0.001), and ZOL ( P < 0.001) and SUV ( P < 0.001). All LEM doses showed significantly decreased (better performance) mean CFB max versus ZOL (all P < 0.001), but not SUV. Notably, all cognitive effects in the CRT and divided attention test were limited to the main treatment phase (up to 8 hours postdose)., Implications/conclusions: All active doses of LEM, ZOL, and SUV generally increased reaction time and reduced divided attention capabilities versus PBO. However, at therapeutic/supratherapeutic doses, LEM led to significantly less cognitive impairment than supratherapeutic doses of ZOL in some measures., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objectives: Serdexmethylphenidate (SDX) chloride (Cl) is a novel prodrug of d-methylphenidate (d-MPH). These studies evaluated the abuse potential of SDX Cl when administered orally, intranasally (IN), and intravenously (IV)., Methods: Three randomized, double-blind, placebo- and active-controlled crossover studies were conducted in recreational drug users to evaluate the abuse-related effects of oral SDX (120 and 240 mg) vs. extended-release (ER) d-MPH (80 mg) and phentermine (60 mg); IN SDX (80 mg) vs. d-MPH (40 mg), and IV SDX (30 mg) vs. d-MPH (15 mg). Abuse-related subjective measures, pharmacokinetics, and safety were assessed., Results: The primary endpoint of maximum (E max ) Drug Liking (DL) (0-100-point scale) was significantly higher following d-MPH vs. placebo, validating the studies. In the oral study, DL E max was significantly higher following 80 mg ER d-MPH (E max = 81.5) than 120 mg SDX (E max = 62.8, p  < .001) and 240 mg SDX (E max = 63.8, p = .006); and following 60 mg phentermine (E max = 80.2) than 120 mg SDX ( p  = .0195), but not 240 mg SDX ( p  = .0665). DL E max scores were significantly higher following IN d-MPH vs SDX (E max = 93.2 vs. 71.0, p  < .0001) and following IV d-MPH vs. SDX (E max = 84.3 vs. 56.6, p  = .001). Intravenous SDX was non-inferior to placebo ( p  = .001) for DL E max . Secondary endpoints (e.g. Take Drug Again) were generally consistent with the primary endpoint. Maximal and overall d-MPH exposure was lower for SDX than d-MPH for all routes. Adverse events typical of stimulants were more frequent with d-MPH than SDX., Conclusions: These findings indicate that the novel d-MPH prodrug, SDX, has lower abuse potential than d-MPH and support its classification as a C-IV controlled substance.

Background: Lemborexant is a dual orexin receptor antagonist approved to treat insomnia in adults in several countries including the USA, Canada, and Japan., Aims: This study was conducted to investigate effects of lemborexant and alcohol coadministration on postural stability, cognitive performance, and the pharmacokinetics, safety, and tolerability of lemborexant., Methods: This was a Phase 1, double-blind, placebo-controlled, four-period crossover study in 32 healthy adults. Individuals were randomized into one of four treatment sequences to receive single doses of placebo, lemborexant 10 mg (LEM10), alcohol (males, 0.7 g/kg; females, 0.6 g/kg), and LEM10 plus alcohol, each separated by a 14-day washout. Postural stability (body sway) was measured by ataxiameter and a cognitive performance assessment battery evaluated four domains of attention and memory., Results: Pharmacodynamic outcomes were analyzed for the 18 participants who completed all four treatments. Change from baseline in body sway showed no significant differences between lemborexant plus alcohol versus alcohol alone. Compared with alcohol alone, coadministration of lemborexant with alcohol showed additive negative effects on cognitive performance domains, corresponding approximately with peak plasma lemborexant concentrations (median = 1.5 h). Cognitive performance was also impaired with lemborexant alone at 0.5 and 2 h in this experimental paradigm with morning dosing. Alcohol increased plasma lemborexant exposure by 70% based on area under the curve to 72 h, and increased peak plasma lemborexant concentrations by 35%. The most commonly reported treatment-emergent adverse event was somnolence., Conclusion: Coadministration of lemborexant with alcohol showed additive negative effects on cognitive measures, but not on postural stability, compared with alcohol alone. Lemborexant exposure was increased with alcohol. Lemborexant alone or with alcohol was well tolerated. Patients are advised not to consume alcohol with lemborexant.

Chronic antihypertensive treatment often includes combination of two or more therapies with complementary mechanism of action targeting different blood pressure (BP) control system. If available, these components are recommended to be administered as a fixed-dose combination (FDC) to reduce tablet burden, improve adherence and thus BP control. A combination of ramipril (RAMI) and bisoprolol (BISO) is one of the options used in clinical practice and is supported by therapeutic guidelines. The clinical program for a novel BISO/RAMI FDC consisted of two randomized, open-label, bioequivalence (BE) studies and one drug-drug interaction (DDI) study. The BE was examined between two FDC strengths of BISO/RAMI (10/10 and 10/5 mg) and the individual reference products administered concomitantly at respective doses after a single oral dose under fasting conditions. In both BE studies, 64 healthy subjects were randomized according to a two-way crossover design. The DDI study evaluated a potential pharmacokinetic (PK) interaction between BISO 10 mg and RAMI 10 mg following their single or concomitant administrations in 30 healthy subjects under fasting condition. BE for BISO/RAMI 10/5 mg and absence of a clinically relevant PK DDI between BISO and RAMI was demonstrated as the 90% confidence intervals (CIs) of the geometric mean ratios (GMRs) for area under the concentration time curve (AUC) and maximum concentration (C max ) remained within the acceptance range of 80.00 to 125.00%. However, BE for BISO/RAMI 10/10 mg was not demonstrated, as the lower bound of the 90% CI of C max for RAMI was outside the acceptance range of BE. Both drugs administered alone or combined were well-tolerated. No PK interaction was observed between BISO and RAMI/ramiprilat, since the co-administration of BISO and RAMI 10 mg single doses resulted in comparable rate and extent of absorption for BISO and RAMI when compared to their individual products., (© 2021 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: Human abuse potential studies include multiple measures to assess the subjective effects of central nervous system-active drugs. In this retrospective analysis, measurement properties of commonly used measures were assessed, and factor analysis was conducted to identify a core battery of measures., Methods: Measures of positive, negative and other effects, for example, bipolar "at-the-moment" Drug Liking visual analog scale (VAS), were derived for active controls and placebo from 19 studies in recreational drug users (N = 570). Distribution, placebo response, variability, convergent/discriminant validity, parameter effect sizes (eg, maximum effect [Emax], time-averaged area under the effect curve), and predictive validity were evaluated. A factor analysis was conducted with 9 studies., Results: Most parameters were not normally distributed. Bipolar VAS exhibited the lowest variability. Drug Liking VAS Emax was very sensitive, showed large effect sizes (>1.0), and was moderately to strongly correlated with Emax of other positive effects measures (r > 0.5), but weaker with less specific scales (eg, high, Any Effects VAS); time-averaged area under the effect curve showed higher variability and lower effect sizes. Maximum effect at any dose (EmaxD) was significantly correlated with Emax across all selected measures and showed higher effect sizes. In the overall factor analysis, factors could be categorized into positive effects/euphoria (77% of variance), negative effects (17.9%), and pharmacologic effects (5%). For predictive validity, effect sizes for Drug Liking VAS Emax/EmaxD were moderately correlated with postmarket adverse events related to abuse (R = 0.52)., Conclusions: A core battery of 7 subjective measures was proposed, with additional measures added based on pharmacologic effects.

Objectives: To evaluate the human abuse potential of pitolisant, a selective histamine 3 (H3)-receptor antagonist/inverse agonist recently approved by the US Food and Drug Administration for the treatment of excessive daytime sleepiness in adult patients with narcolepsy., Methods: Nondependent, recreational stimulant users able to distinguish phentermine HCl 60 mg from placebo in a drug discrimination test were randomized in a four-period, double-blind, crossover design to receive single doses of pitolisant 35.6 mg (therapeutic dose), pitolisant 213.6 mg (supratherapeutic dose), phentermine HCl 60 mg, and placebo. The primary endpoint was maximum effect (Emax) on the 100-point Drug Liking ("at this moment") visual analog scale., Results: In 38 study completers (73.7% male; 65.8% white; mean age, 33.3 years), mean Drug Liking Emax was significantly greater for phentermine versus pitolisant 35.6 mg (mean difference, 21.4; p < 0.0001) and pitolisant 213.6 mg (mean difference, 19.7; p < 0.0001). Drug Liking Emax was similar for pitolisant (both doses) and placebo. Similarly, for key secondary measures of Overall Drug Liking and willingness to Take Drug Again, mean Emax scores were significantly greater for phentermine versus pitolisant (both doses) and similar for pitolisant (both doses) versus placebo. The incidence of adverse events was 82.1% after phentermine HCl 60 mg, 72.5% after pitolisant 213.6 mg, 47.5% after pitolisant 35.6 mg, and 48.8% after placebo administration., Conclusions: In this study, pitolisant demonstrated significantly lower potential for abuse compared with phentermine and an overall profile similar to placebo; this suggests a low risk of abuse for pitolisant., Clinical Trial Registration: ClinicalTrials.gov NCT03152123. Determination of the abuse potential of pitolisant in healthy, nondependent recreational stimulant users. https://clinicaltrials.gov/ct2/show/NCT03152123., (© Sleep Research Society 2019. Published by Oxford University Press [on behalf of the Sleep Research Society].)

Objective: To identify key characteristics and habits of recreational opioid users., Design: The data were compiled from volunteers who participated in clinical studies at a contract research organization in Toronto, Ontario, Canada., Interventions: Data were collected from 5,018 male and female recreational opioid users via telephone and face-to-face screening interviews. Five recreational opioid users participated in a live interview broadcast on the internet., Main Outcome Measures: Demographic data, recreational drug use history, routes of recreational drug administration, alcohol use, and smoking status. A subset of the demographic information and recreational drug use history was summarized separately using data collected between 2013 and 2016 from 114 recreational opioid users who were not dependent on opioids. Interview excerpts were included from five recreational opioid users who described their real-world experiences with drug abuse, including the impact of abuse-deterrent opioid formulations on their drug abuse behavior., Results: The preferred route of administration of opioids was oral (52 percent), followed by intranasal (36 percent), intravenous (10 percent), and buccal (chewing on a patch; 2 percent). Other substances used included nicotine, alcohol, and non-opioid psychoactive drugs (primarily cannabis). Oxycodone was the most frequently reported opioid of abuse., Conclusions: Recreational opioid users have distinct drug-related behaviors and preferences. Monitoring current trends and examining these behaviors is an important component to understand the potential safety risks associated with recreational opioid use., Competing Interests: Sponsored Review

Objective: To review the effects of naltrexone on withdrawal-related adverse events (AEs) and euphoria-related effects, and the relationship between plasma naltrexone concentrations and withdrawal across EMBEDA (MSN; extended-release morphine sulfate with sequestered naltrexone) studies., Methods: Five studies in pain patients and a safety review summarizing AE reports during the first year following approval of MSN were assessed for withdrawal reports. Three of these studies also assessed Clinical Opiate Withdrawal Scale (COWS) scores. Plasma naltrexone concentrations of MSN-treated individuals were summarized. Abuse potential was assessed in four studies in non-dependent recreational opioid users., Results: Withdrawal AEs occurred in 13/1781 patients across five MSN studies, and 25/182 cases involving withdrawal were reported in the safety review. In three of these studies, 11/964 patients experienced moderate withdrawal (COWS score = 13-24) and 1/964 patients experienced moderately severe withdrawal (score = 28); all were either non-compliant with study drug, had undetectable plasma naltrexone concentrations, or were tapering to placebo. In ≥89% of plasma naltrexone concentration samples from patients who took MSN (n = 166), naltrexone was below the limit of quantification (4.0 pg/mL). In four studies with non-dependent recreational opioid users (n = 118), crushed MSN was associated with significantly lower scores of drug liking, high, and take drug again than crushed morphine sulfate (p ≤ 0.005)., Conclusions: When taken intact as directed, naltrexone in MSN does not precipitate withdrawal. However, when MSN is crushed, naltrexone mitigates, but does not eliminate, the euphorigenic effects of crushed morphine sulfate.

Samidorphan is a μ-opioid receptor antagonist in development for the treatment of schizophrenia, in combination with olanzapine, and major depressive disorder, in combination with buprenorphine, at proposed therapeutic doses of samidorphan 10 mg and 2 mg, respectively. A double-blind, double-dummy, active- and placebo-controlled, crossover study evaluated the abuse potential of samidorphan in healthy, nondependent, recreational opioid users. Following a qualification phase, participants were randomized to 1 of 6 treatment sequences of study drugs: placebo, samidorphan (10 or 30 mg), oxycodone (40 mg), pentazocine (30 mg), and naltrexone (100 mg) in a 6 × 6 Williams design. The primary end point was maximum effect (E max ) for "at-the-moment" Drug Liking visual analog scale scores. Secondary end points included E max visual analog scale scores for Take Drug Again and Overall Drug Liking and safety assessments. Among 47 participants, at-the-moment E max Drug Liking scores for positive study controls oxycodone and pentazocine were significantly higher than placebo (P < .001) and samidorphan (both doses; P < .001). Both samidorphan doses had E max Drug Liking scores similar to placebo and naltrexone (median within-subject differences of 0.0). E max Take Drug Again scores for samidorphan (both doses) were higher than placebo, but similar to naltrexone, an unscheduled μ-opioid receptor antagonist. Adverse events to evaluate abuse potential occurred less frequently with samidorphan, naltrexone, and placebo than with oxycodone and pentazocine. Findings from this study support a lack of abuse potential with samidorphan at doses up to 30 mg and a safety profile consistent with previous samidorphan clinical studies., (© 2018, The American College of Clinical Pharmacology.)

Buprenorphine/samidorphan combination (BUP/SAM) is an opioid system modulator being investigated as adjunctive treatment for major depressive disorder. BUP/SAM is a fixed-dose combination of buprenorphine, a partial μ-opioid receptor agonist and κ-opioid receptor antagonist, and samidorphan, a μ-opioid receptor antagonist added to address the abuse and dependence potential of buprenorphine. In this study, we assessed the effect of samidorphan on the abuse potential of buprenorphine in the BUP/SAM combination in nondependent, recreational, adult opioid users (ClinicalTrials.gov ID: NCT02413281). Participants were randomized to 6 treatments in a blinded, Williams crossover design: placebo, BUP/SAM at the intended therapeutic dose (2 mg/2 mg), at 4-fold (8 mg/8 mg) and 8-fold (16 mg/16 mg) the therapeutic dose, and buprenorphine alone (8 mg and 16 mg). The primary end point was maximum effect (E max ) on the visual analog scale for "at the moment" Drug Liking. E max of Drug Liking for the BUP/SAM 2 mg/2 mg dose was similar to that for placebo (median within-subject difference [90% confidence interval]: 2.5 [0.0-9.0]). The supratherapeutic doses of BUP/SAM showed differences of small magnitude on Drug Liking E max compared to placebo. Drug Liking E max for all BUP/SAM doses were significantly lower than those observed for either buprenorphine dose alone. Fewer participants reported adverse events associated with abuse potential with BUP/SAM than with buprenorphine alone, and the overall safety profile of BUP/SAM was consistent with prior reports in healthy volunteers. These findings indicate that samidorphan substantially reduces the abuse potential of buprenorphine in the BUP/SAM combination., (© 2018, The American College of Clinical Pharmacology.)

Rationale: Treatment 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., Methods: This 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 (E max ) on Drug-Liking visual analog scale (VAS). Other measurements included E max 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 Results: Of 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 E max (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 E max 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 E max 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., Conclusion: Administration 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., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

With the development of opioid abuse-deterrent formulations (ADFs), there is a need to conduct well-designed human abuse potential studies to evaluate the effectiveness of their deterrent properties. Although these types of studies have been conducted for many years, largely to evaluate inherent abuse potential of a molecule and inform drug scheduling, methodological approaches have varied across studies. The focus of this review is to describe current "best practices" and methodological adaptations required to assess abuse-deterrent opioid formulations for regulatory submissions. A literature search was conducted in PubMed® to review methodological approaches (study conduct and analysis) used in opioid human abuse potential studies. Search terms included a combination of "opioid," "opiate," "abuse potential," "abuse liability," "liking," AND "pharmacodynamic," and only studies that evaluated single doses of opioids in healthy, nondependent individuals with or without prior opioid experience were included. Seventy-one human abuse potential studies meeting the prespecified criteria were identified, of which 21 studies evaluated a purported opioid ADF. Based on these studies, key methodological considerations were reviewed and summarized according to participant demographics, study prequalification, comparator and dose selection, route of administration and drug manipulation, study blinding, outcome measures and training, safety, and statistical analyses. The authors recommend careful consideration of key elements (eg, a standardized definition of a "nondependent recreational user"), as applicable, and offer key principles and "best practices" when conducting human abuse potential studies for opioid ADFs. Careful selection of appropriate study conditions is dependent on the type of ADF technology being evaluated.

Objective: To assess the intranasal (IN) human abuse potential of ELI-200, a novel immediate-release (IR) oxycodone formulation containing sequestered naltrexone., Design: Randomized, double-blind, double-dummy, active and placebo-controlled, five-way crossover study. Pharmacodynamics, safety, and pharmacokinetics (PKs) were evaluated for up to 36 hours postdose., Setting: Single site in Canada (INC Research Toronto)., Participants: Healthy male and female nondependent recreational opioid users underwent a naloxone challenge and drug discrimination qualification test., Intervention: Single IN dose of ground ELI-200 (30-mg oxycodone hydrochloride [HCl]/3-mg naltrexone HCl), crushed 30-mg oxycodone HCl IR (Roxicodone®), placebo, fixed placebo, and single oral dose of intact ELI-200 (30mg/3mg)., Main Outcome Measure: Peak effect (E max ) for bipolar Drug Liking (0-100 point visual analog scale)., Results: Of the 44 randomized subjects, 37 completed all five treatment periods. All active treatments showed significantly higher (p<0.001) median Drug Liking E max relative to placebo. Significant reductions (p<0.001) in median Drug Liking [E max ] were observed for IN ELI-200 [56.0] compared to IN oxycodone IR [100.0]. Secondary positive or objective measures (High, Good Drug Effects, Overall Drug Liking, Take Drug Again, and maximum pupil constriction) showed significantly lower E max for IN ELI-200 (p<0.001) compared to IN oxycodone IR., Conclusions: IN administration of ELI-200 demonstrated significantly decreased effects on subjective and physiologic measures, and greater nasal irritation, compared to IN oxycodone IR. These findings, along with the PK profile of naltrexone, demonstrated that when ELI-200 capsules were ground and administered intranasally, the naltrexone component was rapidly released and conferred meaningful abuse-deterrent properties.

Accurate assessment of inappropriate medication use events (ie, misuse, abuse, and related events) occurring in clinical trials is an important component in evaluating a medication's abuse potential. A meeting was convened to review all instruments measuring such events in clinical trials according to previously published standardized terminology and definitions. Only 2 approaches have been reported that are specifically designed to identify and classify misuse, abuse, and related events occurring in clinical trials, rather than to measure an individual's risk of using a medication inappropriately: the Self-Reported Misuse, Abuse, and Diversion (SR-MAD) instrument and the Misuse, Abuse, and Diversion Drug Event Reporting System (MADDERS). The conceptual basis, strengths, and limitations of these methods are discussed. To our knowledge, MADDERS is the only system available to comprehensively evaluate inappropriate medication use events prospectively to determine the underlying intent. MADDERS can also be applied retrospectively to completed trial data. SR-MAD can be used prospectively; additional development may be required to standardize its implementation and fully appraise the intent of inappropriate use events. Additional research is needed to further demonstrate the validity and utility of MADDERS as well as SR-MAD., Perspective: Identifying a medication's abuse potential requires assessing inappropriate medication use events in clinical trials on the basis of a standardized event classification system. The strengths and limitations of the 2 published methods designed to evaluate inappropriate medication use events are reviewed, with recommended considerations for further development and current implementation., (Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.)

Background: Establishing content validity is an essential component of instrument development., Objective: To assess the content validity and patient interpretation of the Self-Reported Misuse, Abuse and Diversion of Prescription Opioids (SR-MAD) instrument., Methods: A cross-sectional, qualitative study was conducted in patients with chronic or acute pain. Patients were recruited from three patient groups (opioid naïve, known opioid abusers, and chronic opioid non-abusers). After patients completed the SR-MAD, they participated in an in-person cognitive interview to assess the patient's understanding of the instrument. Descriptive statistics and content analysis were performed., Results: Fifty-seven patients (Wave 1: 20; Wave 2: 37) were enrolled and completed the SR-MAD and cognitive interview. Mean age was 54.5 ± 13.7 years (range 25-84) with 12.5 years of living with pain. The most common chronic pain conditions were back pain (68%), neck pain (32%), and osteoarthritis (25%). Overall, most patients understood the meaning of each question and were able to describe each item using their own words. Many patients reported that some questions were not applicable to them but understood the meaning of the questions as well as the need to ask questions about misuse, abuse, and diversion of opioid medications. Minor revisions to the SR-MAD wording, response options, recall period, and the definition of "opioid", were recommended by the patients in both waves., Limitations: Given its qualitative design, this study has a small sample size. Additionally, quantitative validation of the SR-MAD is needed., Conclusion: The SR-MAD, developed based on expert consensus and revised with patient input, is a 15-item self-report instrument that can be used to identify and monitor prescription opioid abuse, misuse, and diversion.

Objective: To evaluate the abuse potential of ALO-02, an abuse-deterrent formulation comprising pellets of extended-release oxycodone hydrochloride surrounding sequestered naltrexone hydrochloride., Design: Randomized, double-blind, placebo-/active-controlled, 6-way crossover study, with naloxone challenge, drug discrimination, and treatment phases., Subjects: Nondependent, recreational opioid users., Methods: Oral administration of crushed and intact ALO-02, crushed immediate-release (IR) oxycodone, and placebo. Primary endpoints were Drug Liking and High measured on visual analog scales and reported as maximum effect (E max ) and area-under-the-effect-curve from 0 to 2 hours (AUE 0-2h ). Other pharmacodynamic, pharmacokinetic and safety assessments were included., Results: Drug Liking and High (E max ) for crushed oxycodone IR 40 mg were significantly higher compared with placebo, confirming study validity ( P  < 0.0001). Drug Liking and High (E max, AUE 0-2h ) for crushed ALO-02 (40 mg/4.8 mg and 60 mg/7.2 mg) were significantly lower compared to corresponding doses of crushed oxycodone IR (40 and 60 mg; P  < 0.0001). Likewise, Drug Liking and High (E max and AUE 0-2h ) for intact ALO-02 60 mg/7.2 mg were significantly lower compared with crushed oxycodone IR 60 mg ( P  < 0.0001). Secondary pharmacodynamic endpoints and plasma concentrations of oxycodone and naltrexone were consistent with these results. Fewer participants experienced adverse events (AEs) after ALO-02 (crushed or intact: 71.1-91.9%) compared with crushed oxycodone IR (100%). Most common AEs following crushed ALO-02 and oxycodone IR were euphoric mood, pruritus, somnolence, and dizziness., Conclusions: The results suggest that ALO-02 (crushed or intact) has lower abuse potential than crushed oxycodone IR when administered orally in nondependent, recreational opioid users., (© 2016 American Academy of Pain Medicine.)

Abuse liability studies usually measure drug liking using 100-mm visual analog scales (VAS), presented as unipolar (liking measured on entire scale) or bipolar (liking and disliking measured with a neutral midpoint). These 2 types of VAS were compared using drug liking ratings from a randomized double-blind crossover study of immediate-release and controlled-release oxycodone in 2 cohorts of nondependent recreational opioid users. Cohort 1 (n = 19) received intact oxycodone 40 mg, intact OxyContin ® 40 and 80 mg, crushed OxyContin ® 40 mg, and placebo, while cohort 2 (n = 16) received intact oxycodone 20, 40, and 80 mg and placebo. In general, bipolar and unipolar ratings were positively correlated (r = 0.72) for all values (n = 2,477). E max for both scales generally had higher correlation than individual responses for active drug or placebo. The correlation for individual scores after placebo treatment for the 2 scales was poor in both cohorts (r = -0.11, cohort 1 and r = 0.17, cohort 2). Both scales performed similarly within the context of the study, but bipolar scales can also assess disliking, which may be a consideration depending on anticipated drug effects. Appropriate participant training on the use of these scales is also necessary to reduce variability., (© 2016, The American College of Clinical Pharmacology.)

Objective: Prescription opioid misuse and abuse is a serious public health concern that can lead to overdose, addiction, and death. The development of opioid formulations designed to deter misuse and abuse is considered an important step towards addressing the problem, but the extent to which abuse-deterrent opioids (ADOs) actually deter abuse in the community requires confirmation through epidemiologic studies. Epidemiologic evaluations of misuse and abuse present several unique challenges related to study design, sources of data, and methodology, particularly for new entrant ADOs with low population exposure. The purpose of this article is to review the critical methodologic issues that must be considered when designing an epidemiologic evaluation of prescription opioid misuse and abuse, and deterrence for new entrant ADOs., Methods: A systematic feasibility assessment was conducted by critically evaluating and applying epidemiologic principles to combinations of epidemiology study design, study directionality, population, data source, clinical and patient-reported endpoints, type of comparator, effect size, and the ability to control for confounding variables., Results: Ten epidemiologic factors were identified that are considered key to an epidemiologic evaluation, and the issues associated with each are summarized., Conclusion: Given the low population exposure of new entrant ADOs, there is limited feasibility in conducting the epidemiologic studies necessary to evaluate the effectiveness of these products in deterring abuse. Clear regulatory guidance is needed.

Objectives: To compare the results of two open-label primary care-based studies that examined investigator assessment of patient risk for prescription opioid misuse, abuse, and diversion relative to patient self-reports and urine drug tests (UDTs)., Methods: Risk assessment data from two open-label, multicenter, primary care-based US studies in patients with chronic pain were compared., Results: In one study (n = 1487), 54.4% of patients were at moderate, 24.8% at high, and 20.8% at low risk based on patients' self-reports at baseline on the Screener and Opioid Assessment for Patients with Pain®-Revised questionnaire. Investigators assigned 1.3% of patients as high risk despite 5.0% self-reporting prior illicit drug use and 15.3% with positive UDT(s) for an illicit drug at baseline. In the second study (n = 684), few patients were considered by investigators to be at high risk for misuse (1.6%), abuse (1.8%), or diversion (1.0%). However, 10.4% of patients reported prior illicit drug use; 23.4% had at least one abnormal baseline UDT; 60% of 537 patients reported on the Self-Reported Misuse, Abuse, and Diversion questionnaire they took more opioids than prescribed; and 10.9% reported chewing/crushing opioids in the past. Of patients completing the Current Opioid Misuse Measure, 40.6% were classified as having aberrant behaviors., Conclusion: A comparison of risk assessment across two studies indicates a tendency for investigators to assess patients as lower risk for opioid-related aberrant behaviors despite a significant proportion self-reporting aberrant behavior and/or presenting with illicit UDTs. These consistent findings underline the importance of appropriate implementation of objective measures and self-reporting tools when evaluating risk in patients., Clinical Trial Registration: www.clinicaltrials.gov identifiers: NCT00640042 and NCT01179191.

Background: ALO-02, comprising pellets of extended-release oxycodone surrounding sequestered naltrexone, is intended to deter abuse., Objective: Determine the abuse potential of intravenous oxycodone combined with naltrexone, which represents simulated crushed ALO-02 in solution, compared with intravenous oxycodone in nondependent, recreational opioid users., Methods: A randomized, double-blind, placebo-controlled, three-way crossover study with naloxone challenge, drug discrimination, and treatment phases. Intravenous treatments included oxycodone hydrochloride 20 mg, oxycodone hydrochloride 20 mg plus naltrexone hydrochloride 2.4 mg (simulated crushed ALO-02 20 mg/2.4 mg), or placebo (0.9% sodium chloride for injection). Primary end points were peak effects (E max ) and area under the effects curve within 2 h postdose (AUE 0-2h ) on drug liking and high visual analog scales., Results: Thirty-three participants were randomized into treatment phase, and 29 completed all treatments. Study validity was confirmed with statistically significant differences in E max for drug liking and high (p < 0.0001) between intravenous oxycodone and placebo. Intravenous simulated crushed ALO-02 resulted in significantly lower scores than oxycodone on drug liking (E max : 58.2 vs. 92.4; AUE 0-2h : 104.3 vs. 152.4) and high (E max : 17.2 vs. 93.1; AUE 0-2h : 12.0 vs. 133.6), respectively (p < 0.0001, all comparisons). More participants experienced adverse events after intravenous oxycodone (n = 27 [90%]) versus intravenous simulated crushed ALO-02 (n = 4 [12.5%]) or placebo (n = 2 [6.5%])., Conclusion: Intravenous administration of simulated crushed ALO-02 resulted in significantly lower abuse potential, as assessed by subjective ratings of drug liking and high, than intravenous oxycodone in nondependent, recreational opioid users. This suggests that injection of ALO-02 may not be as desirable to recreational opioid users compared with oxycodone taken for nonmedical reasons.

Abuse-deterrent formulations are one strategy for mitigating the epidemic of prescription opioid abuse. Regulatory guidance documents describe the requirements for developing abuse-deterrent formulations of novel drugs and formulations; however, they do not address "abuse-deterrence equivalence" for generic formulations. As generics may be produced with different excipients and formulations compared to reference drugs, differences in their properties may impact their abuse-deterrent features. Currently, it is unclear what specific studies are needed to support generic abuse-deterrence claims. This commentary outlines several recommendations on the in vitro and in vivo testing required, including the conditions for conducting a human abuse potential study.