Research design considerations for clinical studies of abuse-deterrent opioid analgesics: IMMPACT recommendations

Abuse-deterrent formulations and opioid-related harms in North Carolina, 2010-2018

Abuse-deterrent formulations of opioid analgesics (ADFs) were introduced to reduce opioid-related harms among pain patients, but postmarketing study results have been mixed. However, these studies may be subject to bias from selection criteria, comparator choice, and potential confounding by "indication," highlighting the need for thorough study design considerations. In a sample of privately insured patients prescribed ADF or non-ADF extended-release/long-acting (ER/LA) opioids in North Carolina, we implemented a version of the prevalent new-user design to evaluate the relationship between ADFs and opioid use disorder (OUD, n = 235) and opioid overdose (n = 18) through 6 months of follow-up using inverse probability-weighted cumulative incidence functions and Fine-Gray models. The weighted hazard ratio (HRw) of opioid overdose among patients initiating ADFs was 0.87 (95% CI, 0.23-3.24) times as high as among patients who initiated, restarted, or continued non-ADF ER/LA opioids. We observed a short-term benefit of ADFs for incident OUD (HRw = 0.58; 95% CI, 0.35-0.93) compared to non-ADF ER/LA opioids in the first 6 weeks of follow-up, but this benefit disappeared later in follow-up (HRw = 1.30; 95% CI, 0.86-1.95). In summary, our findings add to the expanding body of evidence that there is no clear long-term reduction in harm from ADF opioids among patients in outpatient use. This article is part of a Special Collection on Pharmacoepidemiology.

Matching study design to prescribing intention: The prevalent new-user design for studying abuse-deterrent formulations of opioids

PURPOSE

In drug studies, research designs requiring no prior exposure to certain drug classes may restrict important populations. Since abuse-deterrent formulations (ADF) of opioids are routinely prescribed after other opioids, choice of study design, identification of appropriate comparators, and addressing confounding by "indication" are important considerations in ADF post-marketing studies.

METHODS

In a retrospective cohort study using claims data (2006-2018) from a North Carolina private insurer [NC claims] and Merative MarketScan [MarketScan], we identified patients (18-64 years old) initiating ADF or non-ADF extended-release/long-acting (ER/LA) opioids. We compared patient characteristics and described opioid treatment history between treatment groups, classifying patients as traditional (no opioid claims during prior six-month washout period) or prevalent new users.

RESULTS

We identified 8415 (NC claims) and 147 978 (MarketScan) ADF, and 10 114 (NC claims) and 232 028 (MarketScan) non-ADF ER/LA opioid initiators. Most had prior opioid exposure (ranging 64%-74%), and key clinical differences included higher prevalence of recent acute or chronic pain and surgery among patients initiating ADFs compared to non-ADF ER/LA initiators. Concurrent immediate-release opioid prescriptions at initiation were more common in prevalent new users than traditional new users.

CONCLUSIONS

Careful consideration of the study design, comparator choice, and confounding by "indication" is crucial when examining ADF opioid use-related outcomes.

Biobehavioral Assessments in BACPAC: Recommendations, Rationale, and Methods

The Biobehavioral Working Group of BACPAC was charged to evaluate a range of psychosocial, psychophysical, and behavioral domains relevant to chronic low back pain, and recommend specific assessment tools and procedures to harmonize biobehavioral data collection across the consortium. Primary references and sources for measure selection were the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials, the Minimum Data Set from the National Institutes of Health (NIH) Research Task Force on Standards for Chronic Low Back Pain, the Patient-Reported Outcomes Measurement Information System, and NeuroQOL. The questionnaire's recommendations supplemented the NIH HEAL Common Data Elements and BACPAC Minimum Data Set. Five domains were identified for inclusion: Pain Characteristics and Qualities; Pain-Related Psychosocial/Behavioral Factors; General Psychosocial Factors; Lifestyle Choices; and Social Determinants of Health/Social Factors. The Working Group identified best practices for required and optional Quantitative Sensory Testing of psychophysical pain processing for use in BACPAC projects.

Emerging trends in Abuse-Deterrent Formulations: Technological insights and Regulatory considerations

BACKGROUND

Opioid medications are an integral part in the management of acute and chronic severe pain. However, non-medical practice of these prescription drug products is emerging as a serious public health problem. To control this opioid epidemic, USFDA is encouraging pharmaceutical companies to develop Abuse Deterrent Formulations (ADFs). Abuse Deterrent Formulations are much more difficult to manipulate and abuse when compared to their conventional formulations. This feature of ADFs is due to their ability to incumber extraction of active ingredients, to prevent administration through alternative routes and making abuse of altered product less rewarding.

OBJECTIVE

The main objective of this review is to abridge different ADFs and various laboratory-based in vitro manipulation and extraction studies, demonstrating that these approved ADFs have capabilities to deter abuse.

METHODS

The method includes collection of data from different search engines like PubMed, FDA guidance documents, ScienceDirect, Google Patents to get coverage of literature in order to get appropriate information regarding ADFs.

RESULTS

Various in vitro studies demonstrate that ADFs are effective in minimizing opioid drug abuse including opioid overdose. However, real impact of these ADFs on reducing the drug abuse can be concluded only after receiving the post marketing data.

CONCLUSION

ADFs are embracing fundamentally different paradigm in management of severe pain. We believe that development of abuse deterrent technologies would shift the architype, deterring multipill abuse and can prove as a breakthrough strategy in controlling this opioid epidemic menace.

Abuse-Deterrent Opioids: A Survey of Physician Beliefs, Behaviors, and Psychology

Objective

Evaluate beliefs and behaviors pertaining to abuse-deterrent opioids (ADFs).

Design

Survey in 2019 by invitation to all licensed physicians.

Setting

Commonwealth of Kentucky.

Participants

374 physicians.

Methods

Descriptive statistics, and hypothesis test that early adopter prescribers would have greater endorsement of opioid risk management.

Results

Of all prescribers, 55% believed all opioid analgesics should have ADF requirements (15% were unsure); 74% supported mandating insurance coverage. Only one-third considered whether an opioid was ADF when prescribing, motivated by patient family diversion (94%) and societal supply reduction (88%). About half believed ADFs were equally effective in preventing abuse by intact swallowing, injection, chewing, snorting, smoking routes. Only 4% of OxyContin prescribers chose it primarily because of ADF properties. Instead, the most common reason (33%) was being started by another prescriber. A quarter of physicians chose not to prescribe ADFs because of heroin switching potential. Early adopters strongly believed ADFs were effective in reducing abuse (PR 3.2; 95% CI 1.5, 6.6) compared to mainstream physicians. Early-adopter risk-management practices more often included tools increasing agency and measurement: urine drug screens (PR 2.0; 1.3, 3.1), risk screening (PR 1.3; 0.94, 1.9). While nearly all respondents (96%) felt that opioid abuse was a problem in the community, only 57% believed it was a problem among patients in their practice. Attribution theory revealed an externalization of opioid abuse problems that deflected blame from patients on to family members.

Conclusions

The primary motivator for prescribing ADFs was preventing diversion by family members, not patient-level abuse concerns.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-021-00343-z.

Elevated customary alcohol consumption attenuates opioid effects

BACKGROUND

Regular alcohol consumption is on the rise among older adults and has the potential of altering the subjective experience of pain and response to pain medications. This study examined the cognitive, analgesic and side effect response to oxycodone in middle age and older adults with elevated levels of customary alcohol consumption in a human laboratory setting.

METHODS

After refraining from alcohol for one day, eligible participants underwent baseline assessment cognition and side effects by means of questionnaires that were repeated at three time points (90 min, 5 and 8 h) following administration of a 10 mg oral dose of oxycodone. Response to pain stimulus (Cold Pressor Test (CPT)), pupil size, and plasma oxycodone were also measured.

RESULTS

One hundred twenty-eight adults (age 35-85) completed the study day. Compared to those with lower customary alcohol consumption, participants with elevated alcohol consumption showed attenuated opioid-induced pupil constriction and cognitive decline on objective measures of working memory, sustained attention, inhibitory control, coordination on a simulated driving task, and subjective dysphoric effects with enhanced subjective euphoric effects. Oxycodone pharmacokinetics, pain tolerance to CPT, and Berg balance were impacted comparably between alcohol consumption groups. Women endorsed greater negative drug effects, whereas men endorsed positive drug effects.

CONCLUSION

Independent of subject's age, elevated customary alcohol consumption attenuates opioid central effects (i.e., pupil miosis, impaired cognition) and gender influences subjective drug effects. Clinicians should consider alcohol consumption and gender when prescribing opioid medications.

3D printing in personalized drug delivery: An overview of hot-melt extrusion-based fused deposition modeling

Advancements in pharmaceutical technologies have led to the personalization of therapies over the last decade. Three-dimensional printing (3DP) is an emerging technique in the manufacturing of pharmaceutical dosage forms because of its potential to create complex and customized dosage forms according to the patient's needs. Among the various 3DP techniques based on different functioning mechanisms, fused deposition modeling (FDM) 3D printing is a versatile and widely used method with advantages such as precision of quantity and the ability to incorporate different fill densities. This method is also economical and easily produces complex designs. Hot-melt extrusion (HME) is an established technique in pharmaceutical manufacturing that is utilized in the development of filaments which are used as "ink roll" or feedstock material in FDM 3D printing. This review discusses the various stages involved in FDM 3D printing, including feedstock filament preparation using HME, digital dosage form designs, filament characterization, and various novel applications, and future perspectives.

Prevention of Opioid Abuse and Treatment of Opioid Addiction: Current Status and Future Possibilities

Prescription opioid medications have seen a dramatic rise in misuse and abuse, leading regulators and scientists to develop policies and abuse-deterrent technologies to combat the current opioid epidemic. These abuse-deterrent formulations (ADFs) are intended to deter physical and chemical tampering of opioid-based products, while still providing safe and effective delivery for therapeutic purposes. Even though formulations with varying abuse-deterrent technologies have been approved, questions remain about their effectiveness. While these formulations provide a single means to combat the epidemic, a greater emphasis should be placed on formulations for treatment of addiction and overdose to help those struggling with opioid dependence. This article analyzes various ADFs currently in clinical use and explores potential novel systems for treatment of addiction and prevention of overdose.

Comparing rates and characteristics of ambulance attendances related to extramedical use of pharmaceutical opioids in Australia: a protocol for a retrospective observational study

INTRODUCTION AND AIMS

Extramedical use of, and associated harms with pharmaceutical opioids are common. Analysis of coded ambulance clinical records provides a unique opportunity to examine a national population-level indicator of relative harms. This protocol describes an observational study with three aims: (1) to compare supply adjusted rates of pharmaceutical opioid-related ambulance attendances for buprenorphine, codeine, fentanyl, oxycodone, oxycodone-naloxone, morphine, pethidine, tramadol and tapentadol; (2) to compare presentation characteristics for these commonly used pharmaceutical opioids and (3) to describe the context surrounding ambulance presentations related to oxycodone, a widely used opioid with an established abuse liability, and tapentadol, a more recent 'atypical' opioid on the Australian market, with fewer studies that have directly examined signals of extramedical use.

METHOD

Trained coders extract data from clinical records for ambulance presentations relating to extramedical use of commonly used pharmaceutical opioids. These data form the basis of a large, national database that captures alcohol-related and drug-related harms. Supply adjusted rates of presentations will be examined using Poisson regression. Multinomial logistic regression will be used to compare severity and other characteristics of attendances relating to different pharmaceutical opioids. Tapentadol-related and oxycodone-related cases will be qualitatively examined to understand the situationally specific contexts of the ambulance attendances outside of the characteristics captured in routinely coded variables.

ETHICS AND DISSEMINATION

Ethics approval related to analysis of ambulance attendance data was obtained from the Eastern Health Human Research Ethics Committee (E122 08-09), with an amendment specific to the qualitative analysis. Findings will be submitted for peer review in 2019. The understanding of risk profiles in real-world settings is of international public health importance. The analysis and publication of findings from this national dataset of clinical records will provide one of the most nuanced analyses to date of relative harms across nine pharmaceutical opioids over a 6-year period.

Opportunities and challenges for junior investigators conducting pain clinical trials

Introduction

Clinical investigation serves a vital role to advance treatment and management stratgies for patients with pain. For those new to clinical investigation, key advice for both the novice clinical-investigator and the experienced researcher expanding to translational work may accelerate research efforts.

Objective

To review foundational material relevant to junior investigators focusing on pain clinical trials, with an emphasis on randomized controlled trials.

Methods

We reviewed recent publications and resources relevant to clinical investigators, with a particular emphasis on pain research.

Results

Understanding the approaches and barriers to clinical pain research is a first step to building a successful investigative portfolio. Key components of professional development include motivation, mentorship, and collaborative approaches to research. Many junior clinical-investigators face challenges in pursing research careers and sparking iterative progress towards success in clinical trials. Pain-specific research metrics and goals-including hypothesis development, study design considerations, and regulatory concerns-are also important considerations to junior investigators who pursue clinical trails. Approaches to build toward collaborative and independent funding are essential for investigators.

Conclusions

This work provides a foundation for understanding the clinical research process and helps inform the goals and plans of clinical-investigators.

Post-marketing studies of pharmaceutical opioid abuse-deterrent formulations: a framework for research design and reporting

BACKGROUND AND AIMS

Opioid formulations with properties to deter abuse (abuse-deterrent formulations; ADFs) have been developed as one response to the prescription opioid 'epidemic'. As for all medicines, ADFs undergo evaluation of safety and efficacy prior to registration for marketing. However, reduced extra-medical use (the primary intended outcome of ADFs and reason for their introduction) can only be established in post-marketing observational studies, comparing them to opioid formulations without abuse-deterrent properties. This has implications for various features of study design and analysis. We discuss proposals for the design, conduct, governance and reporting of post-marketing studies on the effectiveness of pharmaceutical and opioid ADFs.

METHODS

A review of current guidance documents, public work-shops and forums and our own experience with post-marketing studies of ADFs.

RESULTS AND CONCLUSIONS

Research questions for post-marketing studies on ADFs of opioids should reasonably be framed around detecting any probable intended or unintended clinical and/or meaningful changes in specific aspects of extra-medical use (e.g. injection use) and harms. Outcomes reported by prevalence and frequency of occurrence and disaggregated by specific product and route of administration can illustrate the magnitude of ADF impact. We argue that a multi-faceted approach is required, using data from both general population and sentinel high-risk cohorts and from primary and secondary data sources. The comparator (historical non-ADF formulation of that opioid, equivalent current generic or similar opioid product), duration of monitoring and analytical approach require justification and should be sufficient to add weight to conclusions of causality. To maximize transparency, we recommend explicit declarations of funding and conflict of interest, establishment of an advisory committee, publication of study protocol and access to study results.

Understanding the evidence for medical cannabis and cannabis-based medicines for the treatment of chronic non-cancer pain

The use of medical cannabis and cannabis-based medicines has received increasing interest in recent years; with a corresponding surge in the number of studies and reviews conducted in the field. Despite this growth in evidence, the findings and conclusions of these studies have been inconsistent. In this paper, we outline the current evidence for medical cannabis and cannabis-based medicines in the treatment and management of chronic non-cancer pain. We discuss limitations of the current evidence, including limitations of randomised control trials in the field, limits on generalisability of previous findings and common issues such as problems with measurements of dose and type of cannabinoids. We discuss future directions for medicinal cannabinoid research, including addressing limitations in trial design; developing frameworks to monitor for use disorder and other unintended outcomes; and considering endpoints other than 30% or 50% reductions in pain severity.

Oral Abuse Potential, Pharmacokinetics, and Safety of Once-Daily, Single-Entity, Extended-Release Hydrocodone (HYD) in Recreational Opioid Users

Objectives. A once-daily, extended-release hydrocodone bitartrate tablet with abuse-deterrent properties (Hysingla ER [HYD]) is available for the treatment of chronic pain in appropriate patients. This study evaluated the oral abuse potential and pharmacokinetics (PK) of HYD intact, chewed, or milled to fine particles in comparison with hydrocodone solution or placebo.

Design. Single-center, double-blind, randomized, five-period, five-treatment crossover study.

Subjects. Healthy adult, nondependent, recreational opioid users.

Methods. Forty subjects received orally administered treatments of hydrocodone 60 mg solution, HYD 60 mg intact, HYD 60 mg chewed, HYD 60 mg milled to fine particles, or placebo, separated by a five- to seven-day washout. Assessments over 36 hours postdose included subjective measures of drug liking and willingness to take drug again (assessed using visual analog scales [VAS]), pupillometry, PK, and safety measures.

Results. Following oral administration, HYD intact, HYD chewed, and HYD fine particles led to significantly lower “at this moment” drug liking compared with hydrocodone solution. HYD intact and chewed were significantly different from hydrocodone solution on overall drug liking, take drug again, and good effects. Pupil constriction, as measured by pupillometry, occurred later with HYD intact and HYD chewed than with hydrocodone solution. Across treatments (hydrocodone solution, HYD fine particles, HYD chewed, and HYD intact, respectively), mean C_max and rate of absorption (C_max/T_max) values decreased, respectively, and median T_max values increased, respectively. Safety was consistent with the known effects of opioid agonists.

Conclusion. HYD demonstrated reduced oral abuse potential compared with hydrocodone solution in healthy adult, nondependent, recreational opioid users.*

Challenges Involved in the Development and Delivery of Abuse-deterrent Formulations of Opioid Analgesics

PURPOSE

This commentary examines the development, regulatory, and reimbursement challenges facing abuse-deterrent formulation (ADF) products.

METHODS

In January 2017, the Tufts Center for the Study of Drug Development convened a roundtable to explore clinical development, regulatory, and reimbursement challenges with respect to ADFs of opioid analgesics. Roundtable participants, who included a range of pharmaceutical industry and other experts, discussed multiple challenges.

FINDINGS

First, several key clinical development challenges were identified and discussed. These challenges pertain to prodrug development and development of deterrents against oral abuse. Second, experts suggested that more clarity is needed from regulatory authorities regarding standards for proving ADF labeling claims and for being rewarded with 3-year data exclusivity. Similarly, given the substantial burdens associated with the development of postapproval evidence generation, experts raised the need for a consistent regulatory policy related to postapproval evidence generation for all ADFs (branded and generic). Third, despite the public health benefits of certain ADF products, current coverage and access policies impede patient access. Payer justification for restrictive policies appears to be based more on budget impact considerations than cost-effectiveness. Fourth, there remains a need to further expand the evidence base regarding clinical and cost-effectiveness as well as abuse deterrence in a real-world setting for all ADF products.

IMPLICATIONS

Clinical development challenges need to be overcome with respect to novel ADF technologies, such as prodrugs and deterrents against oral abuse. More clarity is needed from regulatory authorities on labeling claims and data exclusivity eligibility with respect to ADFs. Ensuring prescriber training and awareness of various options for treating pain, including ADF products, is an important step, as is educating payers about the public health benefits of ADFs in appropriate subpopulations of pain patients. In addition, physicians may need to incorporate appropriate risk stratification methods. Finally, it is important to establish a level playing field between coverage of ADF and non-ADF products so that non-ADF products are not given preferred formulary placement.

Measures That Identify Prescription Medication Misuse, Abuse, and Related Events in Clinical Trials: ACTTION Critique and Recommended Considerations

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.

The ALERRT® instrument: a quantitative measure of the effort required to compromise prescription opioid abuse-deterrent tablets

BACKGROUND

US FDA guidance recommends measuring the degree of effort needed to manipulate abuse-deterrent (AD) opioids. The ALERRT^® instrument (PinneyAssociates; Bethesda, MD) uses visual analog scales to assess the labor, effort, and resources necessary to physically compromise AD product candidates in standardized settings.

OBJECTIVE

Use the ALERRT^® instrument for testing morphine abuse-deterrent, extended-release, injection-molded tablets (ADER-IMT) 60 and 100 mg and the comparators immediate-release (IR) morphine sulfate 30 mg and extended-release (ER) morphine sulfate 60 mg.

METHODS

Four technicians tested the products using 10 household tools. The ALERRT instrument quantified effort (all tools) and time (3 preselected tools) required for manipulation.

RESULTS

Morphine-ADER-IMT 60 and 100 mg were difficult to manipulate, as demonstrated by high scores (mean range, 71.0-99.0 and 77.0-99.5, respectively). IR and ER morphine sulfate were easy to manipulate (low scores; mean range, 2.0-14.8 and 2.3-17.5, respectively). Statistically significant mean differences between morphine-ADER-IMT and comparators' ALERRT scores were observed. Manipulations of morphine-ADER-IMT 60 and 100 mg for 300 seconds failed to produce substantial powdering. Manipulations of IR morphine sulfate (mean range, 65.5-175.8 seconds) and ER morphine sulfate (49.3-163.0 seconds) produced substantial to complete powdering in 92% of tablets.

CONCLUSIONS

Morphine-ADER-IMT was extremely difficult to manipulate versus non-AD formulations of morphine. The ALERRT system differentiated the degree of effort for manipulation of morphine-ADER-IMT and non-AD morphine formulations, indicating sensitivity of this instrument as part of Category 1 testing. By measuring the degree of effort required for manipulation, the ALERRT instrument provides an empirical assessment into the relative difficulty of manipulating opioid analgesics for abuse.

Risk based in vitro performance assessment of extended release abuse deterrent formulations

High strength extended release opioid products, which are indispensable tools in the management of pain, are associated with serious risks of unintentional and potentially fatal overdose, as well as of misuse and abuse that might lead to addiction. The issue of drug abuse becomes increasingly prominent when the dosage forms can be readily manipulated to release a high amount of opioid or to extract the drug in certain products or solvents. One approach to deter opioid drug abuse is by providing novel abuse deterrent formulations (ADF), with properties that may be viewed as barriers to abuse of the product. However, unlike regular extended release formulations, assessment of ADF technologies are challenging, in part due to the great variety of formulation designs available to achieve deterrence of abuse by oral, parenteral, nasal and respiratory routes. With limited prior history or literature information, and lack of compendial standards, evaluation and regulatory approval of these novel drug products become increasingly difficult. The present article describes a risk-based standardized in-vitro approach that can be utilized in general evaluation of abuse deterrent features for all ADF products.

Intranasal Abuse Potential, Pharmacokinetics, and Safety of Once-Daily, Single-Entity, Extended-Release Hydrocodone (HYD) in Recreational Opioid Users

Objectives. A once-daily, extended-release hydrocodone bitartrate tablet with abuse-deterrent properties (Hysingla ER® [HYD]) is available for the treatment of chronic pain in appropriate patients. This study evaluated the intranasal abuse potential and pharmacokinetics of HYD coarse and fine particles vs hydrocodone powder or placebo.

Design. Single-center, double-blind, positive- and placebo-controlled, randomized, four-treatment crossover study.

Subjects. Healthy adult, nondependent, recreational opioid users with a history of intranasal abuse.

Methods. During four treatment periods, subjects (N = 31) received hydrocodone powder 60 mg, HYD coarse particles 60 mg, HYD fine particles 60 mg, or placebo, with five-to-seven-day washouts between treatments. Measures over 36 hours postdose included drug-liking and willingness to take drug again, assessed using visual analog scales (VASs), pupillometry, intranasal irritation, and pharmacokinetics.

Results. Insufflation of both HYD coarse and fine particles led to lower “At this Moment” Drug Liking VAS peak values compared with hydrocodone powder, but higher values compared with placebo (P < 0.001 for all comparisons). Similar results were observed for Overall Drug Liking VAS, Take Drug Again VAS, and Subjective Drug Value. Compared with hydrocodone, insufflation of HYD particles led to reduced miosis and increased nasal irritation. Mean hydrocodone C_max following insufflation of HYD coarse particles, HYD fine particles, and hydrocodone powder was 27.5, 36.5, and 105.8 ng/mL, respectively; median T_max was ≥2-fold longer with either HYD particle size than hydrocodone powder; and (C_max/T_max) was 9.5, 13.4, and 82.0 ng/mL/h, respectively. Safety was consistent with that of opioid agonists.

Conclusions. HYD demonstrated reduced intranasal abuse potential compared with hydrocodone powder.

Abuse-deterrent formulations: transitioning the pharmaceutical market to improve public health and safety

This article evaluates abuse-deterrent formulations (ADFs) as a method to reduce prescription drug abuse while ensuring access to vital medications for individuals with legitimate need; assesses the pros and cons of ADFs and the current state of ADF adoption in the market; and develops policy recommendations to transition the market to ADFs. Although abuse-deterrent technology is still in its nascent stages, ADFs have been proven to reduce prescription drug abuse and its consequences, and even an incremental reduction in abuse can have a significant impact on the nation by reducing the costly social, physical, mental, and public health problems resulting from abuse. Federal ADF policy does not reflect the urgency of the prescription drug abuse epidemic and does not go far enough toward changing the status quo. Policies must be implemented to encourage innovation and a market shift toward ADFs by ensuring any generic medication that references a branded ADF demonstrates that it does not have abuse-deterrent properties inferior to the branded ADF product. Policies must also require federal prescription drug benefit plans to cover ADFs to ensure consumers have access to such medications.

Abuse liability measures for use in analgesic clinical trials in patients with pain: IMMPACT recommendations

Assessing and mitigating the abuse liability (AL) of analgesics is an urgent clinical and societal problem. Analgesics have traditionally been assessed in randomized clinical trials (RCTs) designed to demonstrate analgesic efficacy relative to placebo or an active comparator. In these trials, rigorous, prospectively designed assessment for AL is generally not performed. The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) convened a consensus meeting to review the available evidence and discuss methods for improving the assessment of the AL of analgesics in clinical trials in patients with pain. Recommendations for improved assessment include: (1) performing trials that include individuals with diverse risks of abuse; (2) improving the assessment of AL in clinical trials (eg, training study personnel in the principles of abuse and addiction behaviors, designing the trial to assess AL outcomes as primary or secondary outcome measures depending on the trial objectives); (3) performing standardized assessment of outcomes, including targeted observations by study personnel and using structured adverse events query forms that ask all subjects specifically for certain symptoms (such as euphoria and craving); and (4) collecting detailed information about events of potential concern (eg, unexpected urine drug testing results, loss of study medication, and dropping out of the trial). The authors also propose a research agenda for improving the assessment of AL in future trials.

Abuse potential, pharmacokinetics, pharmacodynamics, and safety of intranasally administered crushed oxycodone HCl abuse-deterrent controlled-release tablets in recreational opioid users

The objective of this study was to evaluate abuse potential, pharmacokinetics, pharmacodynamics, and safety of intranasally administered, crushed reformulated OxyContin® (oxycodone HCl controlled-release) tablets (ORF), relative to crushed original OxyContin® (OC), oxycodone powder (Oxy API), and OC placebo. This randomized, double-blind, positive- and placebo-controlled crossover study enrolled healthy, adult, nonphysically dependent recreational opioid users with recent history of intranasal drug abuse (N = 27). Active treatments contained oxycodone (30 mg). Pharmacokinetics, pharmacodynamics (e.g., Overall Drug Liking [ODL], Take Drug Again [TDA], and High Visual Analog Scales [VAS]; Subjective Drug Value [SDV]; pupillometry; intranasal irritation), and safety (e.g., adverse events, vital signs, laboratory tests) were assessed to 24 hours postdose. Crushed ORF administration yielded reduced oxycodone Cmax and increased Tmax versus crushed OC and Oxy API. Peak effects for pharmacodynamic measures were delayed with ORF (1-2 hours) versus OC and Oxy API (0.5-1 hour). ODL, TDA, High VAS, and SDV Emax values were significantly lower (P ≤ .05) and some intranasal irritation ratings were greater for ORF versus OC and Oxy API. No significant or unexpected safety findings were observed. Compared with OC and Oxy API, intranasally administered ORF was associated with lower and delayed peak plasma concentrations, decreased drug-liking, and decreased intranasal tolerability. This suggests that ORF has a decreased potential for intranasal oxycodone abuse. There were no significant or unexpected safety findings. As is true for all abuse potential studies, epidemiological or other appropriate post-marketing studies are required to assess the impact of the reduction in intranasal oxycodone abuse potential observed in the present study on real-world patterns of ORF misuse, abuse, and diversion.

Transcutaneous electrical nerve stimulation reduces pain, fatigue and hyperalgesia while restoring central inhibition in primary fibromyalgia

Because transcutaneous electrical nerve stimulation (TENS) works by reducing central excitability and activating central inhibition pathways, we tested the hypothesis that TENS would reduce pain and fatigue and improve function and hyperalgesia in people with fibromyalgia who have enhanced central excitability and reduced inhibition. The current study used a double-blinded randomized, placebo-controlled cross-over design to test the effects of a single treatment of TENS with people with fibromyalgia. Three treatments were assessed in random order: active TENS, placebo TENS and no TENS. The following measures were assessed before and after each TENS treatment: pain and fatigue at rest and in movement; pressure pain thresholds, 6-m walk test, range of motion; 5-time sit-to-stand test, and single-leg stance. Conditioned pain modulation was completed at the end of testing. There was a significant decrease in pain and fatigue with movement for active TENS compared to placebo and no TENS. Pressure pain thresholds increased at the site of TENS (spine) and outside the site of TENS (leg) when compared to placebo TENS or no TENS. During active TENS, conditioned pain modulation was significantly stronger compared to placebo TENS and no TENS. No changes in functional tasks were observed with TENS. Thus, the current study suggests TENS has short-term efficacy in relieving symptoms of fibromyalgia while the stimulator is active. Future clinical trials should examine the effects of repeated daily delivery of TENS, similar to the way in which TENS is used clinically on pain, fatigue, function, and quality of life in individuals with fibromyalgia.

Buprenorphine/naloxone as a promising therapeutic option for opioid abusing patients with chronic pain: reduction of pain, opioid withdrawal symptoms, and abuse liability of oral oxycodone

Few studies have examined abuse of prescription opioids among individuals with chronic pain under buprenorphine/naloxone (Bup/Nx) maintenance. The current 7-week inpatient study assessed oral oxycodone self-administration by patients with chronic pain who had a history of opioid abuse. Participants (n=25) were transitioned from their preadmission prescribed opioid to Bup/Nx. All of the participants were tested under each of the sublingual Bup/Nx maintenance doses (2/0.5, 8/2 or 16/4 mg) in random order. During each maintenance period, participants could self-administer oxycodone orally (0, 10, 20, 40 or 60 mg prescription opioids) or receive money during laboratory sessions. Drug choice (percentage) was the primary dependent variable. Subjective ratings of clinical pain and withdrawal symptoms also were measured. Mann-Whitney tests compared percentage of drug choice for each active oxycodone dose to placebo. Logistic regression analyses identified correlates of oxycodone preference, defined as 60% or greater choice of oxycodone compared to money. Pain was significantly reduced while participants were maintained on Bup/Nx compared to preadmission ratings. No differences in percentage drug choice were observed between the active oxycodone doses and placebo under each Bup/Nx maintenance dose. However, factors associated with oxycodone preference were lower Bup/Nx maintenance dose, more withdrawal symptoms and more pain. These data suggest that Bup/Nx was effective in reducing pain and supplemental oxycodone use. Importantly, adequate management of pain and withdrawal symptoms by Bup/Nx may reduce oxycodone preference in this population.

Abuse-deterrent formulations, an evolving technology against the abuse and misuse of opioid analgesics

The increased use of opioid pain medication has been mirrored by the increased misuse and abuse of these drugs. As part of a multidisciplinary approach to this epidemic, pharmaceutical companies, with the encouragement of the Food and Drug Administration, have increased the development of abuse-deterrent formulations. While all have the goal of treating pain while mitigating misuse and abuse, there are different technologies utilized to impart the abuse-deterrent properties. The goal of this paper is to review the basis of abuse-deterrent formulations, the different types and approaches of some of the abuse-deterrent products, and their current regulatory status in the USA.