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

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.

Transparency in the secondary use of health data: assessing the status quo of guidance and best practices

We evaluated what guidance exists in the literature to improve the transparency of studies that make secondary use of health data. To find peer-reviewed papers, we searched PubMed and Google Scholar. To find institutional documents, we used our personal expertise to draft a list of health organizations and searched their websites. We quantitatively and qualitatively coded different types of research transparency: registration, methods reporting, results reporting, data sharing and code sharing. We found 56 documents that provide recommendations to improve the transparency of studies making secondary use of health data, mainly in relation to study registration (n = 27) and/or methods reporting (n = 39). Only three documents made recommendations on data sharing or code sharing. Recommendations for study registration and methods reporting mainly came in the form of structured documents like registration templates and reporting guidelines. Aside from the recommendations aimed directly at researchers, we also found recommendations aimed at the wider research community, typically on how to improve research infrastructure. Limitations or challenges of improving transparency were rarely mentioned, highlighting the need for more nuance in providing transparency guidance for studies that make secondary use of health data.

Use of Causal Framework to Evaluate Effect of Abuse Deterrent Properties of Extended-Release Oxycodone on Tampering in a Real-World Settings

PURPOSE

To assess whether exposure to an extended-release (ER) oxycodone with abuse deterrent properties (ADF) reduced tampering of oxycodone in a real-world, postmarket setting to address the thinking behind Category 4 labeling by the FDA.

METHODS

Data from an observational cross-sectional study of the general adult population (2022) was used under a causal framework to estimate the confounding-adjusted odds of tampering oxycodone after exposure to two types of ADF ER oxycodone. The tampering behaviors of those who used only single entity immediate-release (SE-IR) oxycodone was used as a comparison. The tampering outcome was defined as use by snorting, smoking, or injecting any oxycodone (ER or SE-IR). A directed acyclic graph was used to identify covariates. Average treatment effect among the treated was estimated using inverse propensity score weighting combined with survey weights in a regression.

RESULTS

In 2022, 0.14% and 3.0% among the general population reported using the two ER oxycodone groups, while 2.4% used SE-IR oxycodone. Propensity score analyses with both comparators (common support > 98%) balanced demographic, health, and drug use covariates. After adjustment for selection and confounding bias, among those who used ER oxycodone group 1 the odds ratio of tampering with any form of oxycodone was elevated but not statistically significant (2.25; 95% CI: 0.94, 5.39). The odds ratio of tampering by users of ER oxycodone group 2 was significantly elevated (1.90; 95% CI: 1.08, 3.19).

CONCLUSIONS

Tampering of ER oxycodone products by individuals was rare. We found evidence suggestive of elevated odds of tampering behaviors with use of an ADF ER oxycodone.

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.

Pharmacovigilance Signals of the Opioid Epidemic over 10 Years: Data Mining Methods in the Analysis of Pharmacovigilance Datasets Collecting Adverse Drug Reactions (ADRs) Reported to EudraVigilance (EV) and the FDA Adverse Event Reporting System (FAERS)

In the past twenty years, the consumption of opioid medications has reached significant proportions, leading to a rise in drug misuse and abuse and increased opioid dependence and related fatalities. Thus, the purpose of this study was to determine whether there are pharmacovigilance signals of abuse, misuse, and dependence and their nature for the following prescription opioids: codeine, dihydrocodeine, fentanyl, oxycodone, pentazocine, and tramadol. Both the pharmacovigilance datasets EudraVigilance (EV) and the FDA Adverse Events Reporting System (FAERS) were analyzed to identify and describe possible misuse-/abuse-/dependence-related issues. A descriptive analysis of the selected Adverse Drug Reactions (ADRs) was performed, and pharmacovigilance signal measures (i.e., reporting odds ratio, proportional reporting ratio, information component, and empirical Bayesian geometric mean) were computed for preferred terms (PTs) of abuse, misuse, dependence, and withdrawal, as well as PTs eventually related to them (e.g., aggression). From 2003 to 2018, there was an increase in ADR reports for the selected opioids in both datasets. Overall, 16,506 and 130,293 individual ADRs for the selected opioids were submitted to EV and FAERS, respectively. Compared with other opioids, abuse concerns were mostly recorded in relation to fentanyl and oxycodone, while tramadol and oxycodone were more strongly associated with drug dependence and withdrawal. Benzodiazepines, antidepressants, other opioids, antihistamines, recreational drugs (e.g., cocaine and alcohol), and several new psychoactive substances, including mitragynine and cathinones, were the most commonly reported concomitant drugs. ADRs reports in pharmacovigilance databases confirmed the availability of data on the abuse and dependence of prescription opioids and should be considered a resource for monitoring and preventing such issues. Psychiatrists and clinicians prescribing opioids should be aware of their misuse and dependence liability and effects that may accompany their use, especially together with concomitant drugs.

Abuse Deterrent Formulations in Constraining the Abuse Potential of Prescription Medicines: A Myth or Truth

BACKGROUND

Diverse pain killers used for the management of varied categories of pain are being misused in order to have extreme pleasant effect by a large number of populations. To overcome the misuse of prescription drugs, regulatory bodies have given stress on development of abuse resistance.

METHODS

We studied numerous literatures: (1) Research and review papers including the guidelines for pain management, abuse, and abuse deterrence; (2) Description and categorization of pain along with the management approaches; (3) advantages and disadvantages of the abuse deterrent formulations were described.

RESULTS

Abuse deterrent formulations are the contemporary remedial treatment for pain with reduced prospects of being abused. But these comprise the huge expense in contrast to the generic drugs as well as the non-deterrent branded equivalents.

CONCLUSION

Many challenges are faced throughout the development of abuse deterrent formulations. These formulations displayed substantial drop in abuse incidences but it may lead to other modes of abuse which may prove more harmful for the users.

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.

Effectiveness and framing of pharmaceutical opioid abuse-deterrent formulations

Abuse-deterrent formulations (ADFs) of pharmaceutical opioids have limited capacity to reduce extra-medical use and harm; their impact is likely restricted to prevention of specific practices among population sub-groups. This debate highlights the importance of viewing ADFs as one component in a range of public health responses. Greater involvement of invested parties (e.g., prescribers, consumers) and reframing terminology will reduce discrimination and stigma.

Abuse Deterrent Immediate Release Egg-Shaped Tablet (Egglets) Using 3D Printing Technology: Quality by Design to Optimize Drug Release and Extraction

Opioid abuse is a growing problem and has become a national health crisis over the past decade in the USA. Oral ingestion, snorting, and injection are the most commonly employed routes of abuse for an immediate release product. To circumvent these issues, we have developed an egg-shaped tablet (egglet) using fused deposition modeling (FDM) 3D printing technology. Drug-loaded polymeric filaments (1.5 mm) were prepared using hot melt extrusion (HME) followed by printing into egglets of different sizes and infill densities. Based on printability and crush resistance, polyvinyl alcohol (PVA) was found to be the most suitable polymer for the preparation of abuse deterrent egglets. Further, egglets were evaluated and optimized for mechanical manipulation using household equipment, milling, particle size distribution, solvent extraction, and drug release as per the FDA guidance (November 2017). A multifactorial design was used to optimize egglets for solvent extraction and drug release. Extreme hardness (> 500 N) and very large particle size (> 1 mm) on mechanical manipulation confirmed the snorting deterring property while less than 15% drug extraction in 5 min (% S_ext) demonstrated the deterrence for injection abuse. Quality target product profile D85 < 30 min and % S_ext < 15 was achieved with egglets of 6 mm diameter, 45% infill density, and 15% w/w drug loading. Dose of drug can be easily customized by varying dimension and infill density without altering the composition. HME coupled with FDM 3D printing could be a promising tool in the preparation of patient-tailored, immediate release abuse deterrent formulation.

Conditional power for assessing population interventions

AIM

To calculate conditional power in comparative two-period studies with previously observed baseline data.

METHOD

Isolate the variability attributable to the yet-to-observed data and modify the standard power formulae.

RESULTS

For illustration, we examine rates of opioid overdose before and after a reformulation of one opioid product. The null hypothesis posited no impact of the reformulation, alternative hypotheses posited possible impacts, and ancillary hypotheses posited different secular pre-post changes directly observable in comparators. Conditional power varied with the size of the comparator population and with the assumed pre-post change for the comparator.

CONCLUSION

Pre-post designs can be initiated after the baseline period is over. Power calculations that are conditioned on observed baseline data account differently for variability in the baseline and follow-up periods.