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

Review of Opioid Abuse-Deterrent Formulations: Impact and Barriers to Access

The misuse and abuse of opioid analgesics continue to pose a serious public health concern, but for some patients, opioids remain an important analgesic option. Extended-release (ER) opioid formulations are effective for treating chronic pain and are supported by multiple 12-week efficacy studies. ER opioids often contain a high opioid content, and similar to immediate-release (IR) formulations, are subject to abuse, misuse, and diversion. Unintentional misuse may also occur when ER formulations are manipulated for medicinal administration, such as crushing a dose for easier oral intake. As part of a multipronged strategy designed to fight the opioid epidemic, abuse-deterrent formulations (ADFs) were developed to deter misuse, abuse, and diversion of opioids by making manipulation more difficult and nonoral routes of administration less rewarding. Although ADF opioids have been shown to decrease rates of abuse and diversion, they are not equally effective in terms of deterring manipulation for abuse or misuse. Xtampza ER utilizes DETERx technology, which allows it to retain ER characteristics when chewed or crushed, making it the only ER opioid without a boxed warning against these types of manipulation. OxyContin was also developed as an ADF but uses RESISTEC technology, making the tablet hard to crush and viscous in aqueous solutions. ADF utilization has been hampered by patient access issues, including high prices due to lack of insurance coverage. Postmarket real-world studies demonstrate lower rates of abuse, misuse, and diversion for ADF ER opioids compared with non-ADF formulations. However, similar studies comparing abuse-related effectiveness and health care costs for ADF opioids are warranted if clinicians are expected to utilize these potentially safer opioid formulations. These studies would support further education surrounding the benefits and utilization of ADFs and manipulation potential of different ADFs.

State-level variation in distribution of oxycodone and opioid-related deaths from 2000 to 2021: an ecological study of ARCOS and CDC WONDER data in the USA

OBJECTIVES

This study aims to characterise oxycodone's distribution and opioid-related overdoses in the USA by state from 2000 to 2021.

DESIGN

This is an observational study.

SETTING

More than 80 000 Americans died of an opioid overdose in 2021 as the USA continues to struggle with an opioid crisis. Prescription opioids play a substantial role, introducing patients to opioids and providing a supply of drugs that can be redirected to those seeking to misuse them.

METHODS

The Drug Enforcement Administration annual summary reports from the Automation of Reports and Consolidated Orders System provided weights of oxycodone distributed per state by business type (pharmacies, hospitals and practitioners). Weights were converted to morphine milligram equivalents (MME) per capita and normalised for population. The Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research provided mortality data for heroin, other opioids, methadone, other synthetic narcotics and other/unspecified narcotics.

RESULTS

There was a sharp 280.13% increase in total MME/person of oxycodone from 2000 to 2010, followed by a slower 54.34% decrease from 2010 to 2021. Florida (2007-2011), Delaware (2003-2020) and Tennessee (2012-2021) displayed consistent and substantial elevations in combined MME/person compared with other states. In the peak year (2010), there was a 15-fold difference between the highest and lowest states. MME/person from only pharmacies, which constituted >94% of the total, showed similar results. Hospitals in Alaska (2000-2001, 2008, 2010-2021), Colorado (2008-2021) and DC (2000-2011) distributed substantially more MME/person over many years compared with other states. Florida stood out in practitioner-distributed oxycodone, with an elevation of almost 15-fold the average state from 2006 to 2010. Opioid-related deaths increased +806% from 2000 to 2021, largely driven by heroin, other opioids and other synthetic narcotics.

CONCLUSIONS

Oxycodone distribution across the USA showed marked differences between states and business types over time. Investigation of opioid policies in states of interest may provide insight for future actions to mitigate opioid misuse.

Evaluating the effectiveness of reformulated extended-release oxycodone with abuse-deterrent properties on reducing non-oral abuse among individuals assessed for substance abuse treatment with the Addiction Severity Index-Multimedia Version (ASI-MV)

OBJECTIVE

Original brand extended-release (ER) oxycodone tablets (OC) for oral use were reformulated (ORF) with abuse-deterrent properties (ADP) against inhalation and injection routes in August 2010. This product transition provided an opportunity to compare "before and after" reformulation abuse trends. Our goal was to assess the change in abuse of brand oxycodone ER from before and after introduction of ORF.

METHODS

Change in self-reported non-oral "OxyContin^®" abuse in the previous 30 days during 2 years pre- and 4 years post-reformulation was assessed among adults evaluated for substance use and treatment planning using the Addiction Severity Index-Multimedia Version (ASI-MV^®). Comparator opioids were used to provide a frame of reference for changes in abuse due to competing population-level opioid abuse interventions and other factors unrelated to the reformulation. A proportion (PR) and abuse report dispensing ratio (ARDR) are reported because a single measure of abuse has not been identified that can optimally describe opioid abuse or changes in opioid abuse.

RESULTS

Interrupted time-series analyses indicated an immediate decline in non-oral abuse measures post-reformulation (PR=-52.1%; ARDR=-32.2%). Significant decreases from pre- to post-reformulation in non-oral abuse overall were observed (PR [95% CI]=-30.7% [-46.9%, -9.5%]; ARDR=-29.3% [-37.5%, -20.1%]). Comparator opioids did not demonstrate similar trends over the period.

CONCLUSIONS

Methodology applied in this study suitably assessed the effectiveness of an ADP product. Among individuals assessed for substance use, a differential decline in non-oral abuse of brand ER oxycodone was observed since introduction of ORF.

An Evaluation of the Effect of the OxyContin Reformulation on Unintentional Fatal and Nonfatal Overdose

OBJECTIVES

OxyContin was reformulated with a polyethylene oxide matrix in August 2010 to reduce the potential for intravenous abuse and for abuse by insufflation. The objective of this study was to evaluate the impact of OxyContin's reformulation on overdose (OD) risk for individuals dispensed OxyContin in comparison to those dispensed other opioids under regular care.

MATERIALS AND METHODS

Three national insurance databases with National Death Index linkage identified OD in individuals with any dispensing of OxyContin or a primary comparator opioid (extended release morphine, transdermal fentanyl, or methadone) between July 2008 through September 2015. A difference-in-differences design was used to compare the pre-post reformulation changes in OD rates for OxyContin versus comparators.

RESULTS

A total of 297,836 individuals were dispensed OxyContin and 659,673 individuals were dispensed a primary comparator across the 3 databases. Overall, there was little or no difference in the temporal change in OD incidence in comparators versus OxyContin (Medicaid: adjusted ratio-of-rate-ratios (aRoRs) ranging from 0.90 to 1.05; MarketScan/HIRD: aRoR ranging from 1.10 to 1.22). However, restriction to person-time without concomitant opioid use revealed a modestly greater reduction in OD incidence over time during OxyContin use, as the aRoRs comparing the primary comparators to OxyContin ranged from 1.06 to 1.30 in Medicaid and from 1.64 to 1.85 in MarketScan/HIRD.

DISCUSSION

This study did not detect an overall effect of the OxyContin reformulation on OD in insured patients under regular medical care. There is a suggestion of a modestly reduced OxyContin-associated OD risk following the reformulation but only in commercially insured individuals receiving single-opioid regimens.

Concentration-Response Model of Immediate Release Oxycodone Drug Liking by Different Routes of Abuse

OBJECTIVE

To understand the correlation between oxycodone concentration and drug liking response for immediate-release formulations as they relate to different doses and different routes of administration following manipulation involved in opioid misuse and nontherapeutic use.

METHODS

Concentration-response and noncompartmental analyses of drug liking and plasma oxycodone data from Category 3 human abuse potential studies (n = 15 to 29 per study) were conducted, using Phoenix 6.0 software. Time to onset of a set threshold of subjective effects (Tonset) and offset of subjective effects (Toffset) were estimated based on a baseline pharmacodynamic response set at 50 on a bipolar Drug Liking visual analog scale of 0-100 and the threshold for drug liking set at ≥ 65, based on study qualification criteria. Partial Area Under the Concentration (AUCTonset-Toffset) and Effect (AUETonset-Toffset) profiles were calculated and their correlation with individual partial AUE vs. partial AUC was assessed.

RESULTS

The oxycodone concentration-response (drug liking) was best described by a sigmoidal-effect Emax model (S-shaped). Using a defined threshold, drug liking was closely associated with the rate of rise in concentration and the onset of action for oxycodone administered via oral or intranasal route. Partial AUCTonset-Toffset and AUETonset-Toffset showed a strong linear correlation.

CONCLUSIONS

Results indicate that oxycodone concentration-response and duration of drug liking following manipulation via different routes of administration may be an approach for further exploring drug liking effects of opioids.

Oxycodone in the Opioid Epidemic: High 'Liking', 'Wanting', and Abuse Liability

It is estimated that nearly a third of people who abuse drugs started with prescription opioid medicines. Approximately, 11.5 million Americans used prescription drugs recreationally in 2016, and in 2018, 46,802 Americans died as the result of an opioid overdose, including prescription opioids, heroin, and illicitly manufactured fentanyl (National Institutes on Drug Abuse (2020) Opioid Overdose Crisis. https://www.drugabuse.gov/drugs-abuse/opioids/opioid-overdose-crisis . Accessed 06 June 2020). Yet physicians will continue to prescribe oral opioids for moderate-to-severe pain in the absence of alternative therapeutics, underscoring the importance in understanding how drug choice can influence detrimental outcomes. One of the opioid prescription medications that led to this crisis is oxycodone, where misuse of this drug has been rampant. Being one of the most highly prescribed opioid medications for treating moderate-to-severe pain as reflected in the skyrocketed increase in retail sales of 866% between 1997 and 2007, oxycodone was initially suggested to be less addictive than morphine. The false-claimed non-addictive formulation of oxycodone, OxyContin, further contributed to the opioid crisis. Abuse was often carried out by crushing the pills for immediate burst release, typically by nasal insufflation, or by liquefying the pills for intravenous injection. Here, we review oxycodone pharmacology and abuse liability as well as present the hypothesis that oxycodone may exhibit a unique pharmacology that contributes to its high likability and abuse susceptibility. We will discuss various mechanisms that likely contribute to the high abuse rate of oxycodone including clinical drug likability, pharmacokinetics, pharmacodynamics, differences in its actions within mesolimbic reward circuity compared to other opioids, and the possibility of differential molecular and cellular receptor interactions that contribute to its selective effects. We will also discuss marketing strategies and drug difference that likely contributes to the oxycodone opioid use disorders and addiction.

Preferential Oxycodone Loss of Physically Manipulated Abuse Deterrent Oxycodone HCl Extended Release Tablets Prepared for Nasal Insufflation Studies

A method to reproducibly mill abuse deterrent oxycodone hydrochloride (HCl) extended release (ER) tablets was developed for a nasal insufflation pharmacokinetic (PK) study. Several comminution methods were explored before determining that a conical mill resulted in controlled milling of tablets to a size range equal to or below 1000 μm. However, milling resulted in significant loss of oxycodone from abuse deterrent oxycodone HCl ER tablets compared to minimal oxycodone loss from oxycodone HCl immediate release (IR) tablets. Characterization of milled tablet powder showed that loss of oxycodone was not attributed to analytical procedures or oxycodone phase change during high intensity milling processes. The content uniformity of oxycodone in the milled tablet powder varied when ER and IR tablets were milled to a particle size distribution equal to or below 500 μm but did not vary when particles were sized above 500 µm to equal to or below 1000 μm. In addition, the initial excipient weight to drug substance weight ratio impacted the amount of oxycodone lost from the respective formulation. However, dissolution demonstrated that when oxycodone HCl ER tablets are milled, differences in excipient weight to drug substance weight ratio and particle size distribution of milled tablets did not result in significantly different release of oxycodone.

Particle size affects pharmacokinetics of milled oxycodone hydrochloride tablet products following nasal insufflation in nondependent, recreational opioid users

This study assessed the impact of product particle sizes (fine: 106–500 µm; coarse: 500–1000 µm) on oxycodone pharmacokinetics (PK) following nasal insufflation of milled oxycodone extended‐release (ER) abuse‐deterrent (AD) tablets using immediate‐release (IR) non‐AD product as reference. Additionally, this study assessed the effects of different excipient to drug ratio (EDR) by comparing two products with fine particle size but different EDRs, again using IR non‐AD as the control. Thirty milligrams of oxycodone were administered in each treatment. Coarsely milled 30 mg ER tablets demonstrated significantly lower maximum plasma concentration (C_max) and partial areas under the concentration‐time curve (AUCs) than those of the finely milled IR tablets. Finely milled ER tablets demonstrated similar C_max and partial AUCs but higher total systemic exposures than those of finely milled IR tablets. Finely milled 80 mg ER tablets were bioequivalent to IR tablet on all parameters. The finely milled 30 mg ER tablet was not bioequivalent to the coarsely milled 30 mg ER tablet and had higher values for all parameters. The finely milled 30 mg ER tablets (EDR 6.9) showed no PK differences with finely milled 80 mg ER tablets (EDR 4.9). No serious adverse events were reported. The study demonstrated a significant effect of particle sizes (106–1000 µm) on PK of milled and insufflated oxycodone ER AD tablets. EDR difference did not have any significant effects on the PK of finely milled oxycodone ER AD tablets. Particle size distribution should be considered when nasal AD properties of opioid drug products are investigated during drug development.

Long-term Safety and Tolerability of NKTR-181 in Patients with Moderate to Severe Chronic Low Back Pain or Chronic Noncancer Pain: A Phase 3 Multicenter, Open-Label, 52-Week Study (SUMMIT-08 LTS)

OBJECTIVE

To evaluate the long-term safety of NKTR-181, a novel mu-opioid receptor agonist that may have reduced human abuse potential, in patients with moderate to severe chronic low back pain (CLBP) or other chronic noncancer pain (CNP).

DESIGN

Uncontrolled, multicenter, open-label, long-term study of NKTR-181 comprised of three periods: screening (≤21 days), treatment (52 weeks), and safety follow-up (∼14 days after the last dose of NKTR-181).

SETTING

Multicenter, long-term clinical research study.

METHODS

NKTR-181 administered at doses of 100-600 mg twice daily (BID) was evaluated in opioid-naïve and opioid-experienced patients. Patients were enrolled de novo or following completion of the randomized, placebo-controlled phase 3 efficacy study (SUMMIT-07). Safety assessments included adverse event documentation, measurements of opioid withdrawal, and clinical laboratory tests. Effectiveness was assessed using the modified Brief Pain Inventory Short Form (mBPI-SF).

RESULTS

The study enrolled 638 patients. The most frequently reported treatment-emergent adverse events (TEAEs) were constipation (26%) and nausea (12%). Serious TEAEs, reported in 5% of patients, were deemed by investigators to be unrelated to NKTR-181. There were no deaths or reported cases of respiratory depression. A sustained reduction in mBPI-SF pain intensity and pain interference from baseline to study termination was observed throughout treatment. Only 2% of patients discontinued NKTR-181 due to lack of efficacy, and 11% discontinued due to treatment-related AEs. NKTR-181 doses of up to 600 mg BID were generally well tolerated, and patients experienced low rates of opioid-related adverse events.

CONCLUSIONS

The study results support the premise that NKTR-181 is a safe and effective option for patients with moderate to severe CLBP or CNP.

Abuse-Deterrent Opioid Formulations and the Opioid Crisis: A Pharmacist's Perspective

BACKGROUND

For over 20 years, the United States has suffered the detrimental effects of an opioid epidemic. Extended-release opioid products are particularly prone to abuse due to the high amount of opioid present. By bypassing the controlled-release mechanisms and nonoral administration, individuals experience intense and dangerous "highs." Abuse-deterrent opioid formulations have been recommended as a potential solution to the crisis, but widespread utilization has been stunted and their role in therapy remains unclear owing to limited real-world efficacy data and affordability issues. This review discusses abuse-deterrent opioid formulations, the mechanisms and data underlying available products, and a pharmacist's perspective of their role in the opioid crisis.

METHODS

The authors reviewed PubMed, MEDLINE, and Google Scholar electronic databases for premarketing and postmarketing studies on OxyContin, Xtampza ER, and Hysingla ER.

RESULTS

Studies showed lower rates of abuse (19% reduction), opioid use disorder (27%), overdose (34%), and fatalities (85%) with the reformulated OxyContin when compared with the original product and comparator opioids. However, these studies revealed the potential for bypassing abuse-deterrent mechanisms and diverting abuse to other drugs. Postmarketing studies are unavailable for Xtampza ER or Hysingla ER, although premarketing studies suggested that some controlled-release properties persist when the product is manipulated, indicating that abuse may be more difficult and less rewarding.

CONCLUSIONS

Abuse-deterrent opioid products may lead to reductions in abuse, overdose, and overdose fatalities. However, cost, loopholes in deterrence mechanism, and possible diversion to other substances hinder their role in the opioid crisis. Multiple approaches must be used to improve opioid safety, and further postmarketing and real-world analyses should be performed on available opioid formulations to assess their impact on abuse-related adverse events.

Oxycodone Effect on Pupil Constriction in Recreational Opioid Users: A Pharmacokinetic/Pharmacodynamic Meta-Analysis Approach

INTRODUCTION

Understanding the effect of oxycodone pharmacokinetics (PK) on µ-opioid receptor binding benefits from an integrated approach to compiling the results of multiple studies. The current pharmacokinetic/pharmacodynamic (PK/PD) model analysis brings together various studies to support the interpretation of newly collected PK/PD data, putting the new results into the perspective of the full concentration-effect curve.

METHODS

A two-step modeling approach was applied to characterize the PK of oxycodone and its PK/PD relationship for the pupil diameter as a biomarker for µ-opioid receptor binding in recreational opioid users. First, a model-based meta-analysis (MBMA) was used to quantify the state-of-the-art knowledge from seven published studies, each of which contained part of the data needed for full characterization. Subsequently, the estimated parameters with uncertainty from the MBMA were used as prior information for a model developed on newly collected clinical data after intranasal administration in a clinical abuse potential trial.

RESULTS

The inclusion of intravenous data in the MBMA showed that the PK of oxycodone can be described by a two-compartmental model, and allowed for the estimation of absolute bioavailability after intranasal and oral administration. A hysteresis loop was observed when plotting plasma concentrations and pupil constriction, which was approximated using an effect compartment. The totality of literature data enabled the identification of a Hill equation for the drug effect. The model with prior information fitted successfully to the newly collected data, where most parameter estimates had their confidence intervals overlapping with the prior distribution. The new data led to a slightly lower intranasal absorption rate constant, explaining the longer apparent half-life of oxycodone in the newly collected data. The PK/PD model parameters were confirmed by the new data, leading to the following estimates: half maximal inhibitory concentration (IC₅₀) of 26.5 ng/mL, maximum pupil restriction of 66.0% from baseline, and a Hill factor of 1.05.

CONCLUSIONS

The new data confirmed the PK profile and the PK/PD relationship identified using the MBMA, resulting in similar parameter estimates except for the intranasal absorption rate constant. The latter was lower than in the MBMA and explained the slightly longer apparent half-life of oxycodone in the newly collected data.

Pharmacokinetic and pharmacodynamic considerations in developing a response to the opioid epidemic

Introduction: Opioids continue to be used widely for pain management. Widespread availability of prescription opioids has led to opioid abuse and addiction. Besides steps to reduce inappropriate prescribing, exploiting opioid pharmacology to make their use safer is important.Areas covered: This article discusses the pathology and factors underlying opioid abuse. Pharmacokinetic and pharmacodynamic properties affecting abuse liability of commonly abused opioids have been highlighted. These properties inform the development of ideal abuse deterrent products. Mechanisms and cost-effectiveness of available abuse deterrent products have been reviewed in addition to the pharmacology of medications used to treat addiction.Expert opinion: The opioid crisis presents unique challenges to managing pain effectively given the limited repertoire of strong analgesics. The 5-point strategy to combat the opioid crisis calls for better preventive, treatment, and recovery services, better data, better pain management, better availability of overdose-reversing drugs and better research. There is an urgent need to decrease the cost of abuse deterrent opioids which deters their cost-effectiveness. In addition, discovery of novel analgesics, further insight into central and peripheral pain mechanisms, understanding genomic risk profiles for efficient targeted efforts, and education will be key to winning this fight against the opioid crisis.

Abuse-deterrent opioid analgesics: a guide for clinicians

The US FDA has encouraged the development of abuse-deterrent formulations (ADFs) of opioid analgesics as one component in a comprehensive effort to combat prescription opioid abuse. Guidance issued by the FDA outlines three types of premarket studies for evaluating abuse deterrence: laboratory-based in vitro manipulation and extraction studies, pharmacokinetic studies and human abuse potential studies. After approval, postmarket studies are needed to evaluate the impact of an ADF product on abuse in real-world settings. This review summarizes the regulatory issues involved in the development of ADF opioids and clarifies abuse-deterrence claims in product labels, in order to assist clinicians in critically evaluating the available evidence pertaining to the abuse-deterrent features of opioid analgesics.

Relative Abuse of Crush-Resistant Prescription Opioid Tablets via Alternative Oral Modes of Administration

Objective

Some crush-resistant tablet formulations (CRTs) reduce prescription opioid abuse by nonoral routes of administration (ROAs), especially insufflation and injection, while oral abuse increases. Oral abuse involving product manipulation vs swallowing whole for CRTs and comparators was examined.

Methods

Abuse by oral modes of administration (e.g., swallowing whole, chewing, dissolving in the mouth), was examined using the ASI-MV, a computerized, clinical interview for adults in substance abuse treatment from January 2009 to March 2015. CRTs (reformulated oxycodone extended-release [ER], reformulated oxymorphone ER, and tapentadol ER) were compared with non-CRT versions, morphine ER, and oxycodone immediate-release single entity. Analyses employed descriptive statistics and logistic regression.

Results

Among 364,329 unique assessments, 18,135 patients reported oral abuse of the CRTs and comparators examined. CRTs had a higher prevalence of oral abuse involving product manipulation than comparators (P < 0.0001) among all abusers of product. Oral abuse involving product manipulation for CRTs was greater among the subset of patients reporting oral abuse and significantly higher than comparators (P < 0.003). CRTs were significantly less likely than comparators to be swallowed whole (P < 0.0001) and significantly more likely to be chewed (P < 0.003). CRTs were more likely to be dissolved in the mouth than most comparators.

Conclusions

Results suggest the need for abuse-deterrent formulations designed to reduce abuse by oral administration with product manipulation, such as chewing. Advances in this area may reduce the overall abuse of prescription opioids and interrupt the progression from abuse by swallowing whole to oral administration involving product manipulation and other ROAs.

Opioids: The Painful Public Health Reality

The analgesic, sedative, antidepressant, euphoriant, intoxicating, and addictive properties of opium and its synthetic derivatives are well known and have been known for centuries. Hence, the current major public health problems due to excessive availability should be no surprise. What is unprecedented in the United States, and emerging elsewhere, is the extent of the profound consequences and complexity of addressing this public health crisis.

Alum adjuvant is more effective than MF59 at prompting early germinal center formation in response to peptide-protein conjugates and enhancing efficacy of a vaccine against opioid use disorders

Opioid use disorders (OUD) and fatal overdoses are a national emergency in the United States. Therapeutic vaccines offer a promising strategy to treat OUD and reduce the incidence of overdose. Immunization with opioid-based haptens conjugated to immunogenic carriers elicits opioid-specific antibodies that block opioid distribution to the brain and reduce opioid-induced behavior and toxicity in pre-clinical models. This study tested whether the efficacy of a lead oxycodone conjugate vaccine was improved by formulation in either aluminum hydroxide or the squalene-based oil-in-water emulsion MF59 adjuvant, which was recently FDA-approved for influenza vaccines in subjects 65⁺ years old. In adult BALB/c mice, alum formulation was more effective than MF59 at promoting the early expansion of hapten-specific B cells and the production of oxycodone-specific serum IgG antibodies, as well as blocking oxycodone distribution to the brain and oxycodone-induced motor activity. Alum was also more effective than MF59 at promoting early differentiation of peptide-specific MHCII-restricted CD4⁺ Tfh and GC-Tfh cells in adult C57Bl/6 mice immunized with a model peptide-protein conjugate. In contrast, alum and MF59 were equally effective in promoting hapten-specific B cells and peptide-specific MHCII-restricted CD4⁺ T cell differentiation in older C57Bl/6 mice. These data suggest that alum is a more effective adjuvant than MF59 for conjugate vaccines targeting synthetic small molecule haptens or peptide antigens in adult, but not aged, mice.

Pharmacodynamics and arteriovenous difference of intravenous naloxone in healthy volunteers exposed to remifentanil

PURPOSE

Pharmacodynamic studies of naloxone require opioid agonism. Steady state condition may be achieved by remifentanil TCI (target controlled infusion). Opioid agonism can be measured by pupillometry. It is not known whether there are arteriovenous concentration differences for naloxone. The aim was thus to further develop a model for studying pharmacokinetic/pharmacodynamic aspects of naloxone and to explore whether a significant arteriovenous concentration difference for naloxone in humans was present.

METHODS

Relevant authorities approved this study. Healthy volunteers (n = 12) were given 1.0 mg intravenous (IV) naloxone after steady state opioid agonism was obtained by TCI of remifentanil (1.3 ng/ml). Opioid effect was measured by pupillometry. Arterial and venous samples were collected simultaneously before and for 2 h after naloxone administration for quantification of naloxone and remifentanil.

RESULTS

Arterial remifentanil was in steady state at 12 min. One milligram IV naloxone reversed the effect of remifentanil to 93% of pre-opioid pupil-size within 4 min. The estimated duration of antagonism was 118 min. At that time, the concentration of naloxone was 0.51 ng/ml. The time course of arterial and venous serum concentrations for naloxone was similar, although arterial AUC (area under the curve) was slightly lower (94%) than the venous AUC (p = 0.03). There were no serious adverse events.

CONCLUSION

Onset of reversal by IV naloxone was rapid and lasted 118 min. The minimum effective concentration was 0.5 ng/ml. Using TCI remifentanil to obtain a steady-state opioid agonism may be a useful tool to compare new naloxone products.

Evaluation of the Relative Intranasal Abuse Potential of a Hydrocodone Extended-Release Tablet Formulated with Abuse-Deterrence Technology in Nondependent, Recreational Opioid Users

Objective

To assess the intranasal abuse potential of hydrocodone extended-release (ER) tablets developed with CIMA Abuse-Deterrence Technology compared with hydrocodone powder and hydrocodone bitartrate ER capsules (Zohydro ER, original formulation [HYD-OF]).

Design

Single-dose, randomized, double-blind, quadruple-dummy, active- and placebo-controlled, crossover study.

Setting

One US site.

Subjects

Healthy, adult, nondependent, recreational opioid users.

Methods

Subjects able to tolerate intranasal hydrocodone and discriminate hydrocodone from placebo were eligible for study enrollment. Eligible participants randomly received intranasal hydrocodone ER, intranasal hydrocodone powder, intranasal HYD-OF, intact oral hydrocodone ER, and placebo. Coprimary pharmacodynamic end points were a maximum effect on “at the moment” Drug Liking visual analog scale and Overall Drug Liking visual analog scale. Pharmacokinetics and safety were assessed.

Results

Mean maximum effect for “at the moment” Drug Liking was significantly (P < 0.01) lower for intranasal hydrocodone ER (72.8) compared with hydrocodone powder (80.2) and HYD-OF (83.2). Similar results were observed for Overall Drug Liking maximum effect (68.5 vs 77.1 and 79.8, respectively; P < 0.01). Secondary end points, including balance of effects and positive, sedative, and other effects, were consistent with these results. Intranasal treatments showed significantly greater effects vs placebo, while intact oral hydrocodone ER was similar to placebo. For each treatment, plasma concentration-time profiles paralleled “at the moment” Drug Liking over time. Incidences of adverse events for intranasal treatments were 52% for hydrocodone ER, 53% for hydrocodone powder, and 61% for HYD-OF.

Conclusions

The statistically significant differences between hydrocodone ER vs hydrocodone powder and HYD-OF for the primary drug liking end points indicate a lower intranasal abuse potential with hydrocodone ER in healthy, nondependent, recreational opioid users.

Relative Oral Bioavailability of an Abuse-deterrent, Extended-release Formulation of Morphine Versus Extended-release Morphine: A 2-period, Single-dose, Randomized Crossover Study in Healthy Subjects

PURPOSE

Morphine ARER is a novel oral, abuse-deterrent, extended-release (ER) formulation of morphine sulfate with physical and chemical properties that deter misuse and abuse by nonoral routes of administration. Here we evaluate the relative bioavailability of morphine ARER and extended-release morphine.

METHODS

This single-dose, 2-treatment, 2-period, 2-sequence, randomized crossover study in healthy adult subjects compared the relative bioavailability of morphine ARER 100 mg to that of ER morphine 100 mg in the fasted condition. At 12 and 1.5 hours before dosing and 12 hours after dosing, all subjects received a 50-mg oral naltrexone tablet to minimize opioid-related side effects. Pharmacokinetic parameters including the AUC_0-t, AUC_0-∞, and C_max of morphine and its metabolite morphine-6-glucuronide (M6G) were determined at various times up to 48 hours postdose. The bioequivalence of morphine ARER and ER morphine was determined using an ANOVA of the least-squares mean values of morphine and M6G bioavailability.

FINDINGS

Forty-nine subjects completed the study. Both morphine ARER and ER morphine exhibited peak plasma morphine and M6G concentrations of ∼30 ng/mL and ∼200 ng/mL, respectively, at 3 hours postdose. The 90% CIs of the ln-transformed values of morphine AUC_0-t, AUC_0-∞, and C_max were within the 80% to 125% range for bioequivalence. M6G values also indicated bioequivalence of morphine ARER and ER morphine. The most common adverse events were nausea and somnolence.

IMPLICATIONS

These data show that, in these subjects, morphine ARER was bioequivalent to ER morphine, a treatment for pain with well-established efficacy and safety profiles.

An overview of abuse-deterrent opioids and recommendations for practical patient care

Despite advances in the treatment of severe intractable pain, opioids remain a critical and appropriate component of treatment. However, abuse, misuse, and diversion of prescription opioids are significant public health concerns. Opioid abuse-deterrent formulations (ADFs) are one component of an opioid risk management plan to manage patient’s pain relief and quality of life while offering some protection against potentially harmful consequences of opioids from misuse and abuse. Opioid ADFs are designed to make manipulation more difficult and administration via non-oral routes less appealing. There are currently nine extended-release and one immediate-release opioid pain medications with US Food and Drug Administration-approved ADF labeling. All use physical/chemical barriers or agonist/antagonist combinations to deter manipulation and abuse. Evidence suggests that opioid ADFs decrease rates of abuse and diversion of opioids in the USA; however, some opioid ADFs are not yet commercially available or have not been on the market long enough to undergo post-marketing data analyses. Opioid ADFs along with the use of prescription drug monitoring programs, clinical assessment tools, toxicology testing, and co-prescribing of naloxone are all tools that can be used to reduce opioid abuse. Patient education on the risks of abuse and diversion is vital and includes a discussion of appropriate use of medication and proper storage. Physician assistants and nurse practitioners are on the “front lines” in battling opioid abuse and serve a key role in recognizing and mitigating the risks of prescription opioid diversion, abuse, and misuse (intentional and unintentional) and in identifying patients at risk for abuse while still providing pain relief to patients.

Human Abuse Potential of an Abuse-Deterrent (AD), Extended-Release (ER) Morphine Product Candidate (Morphine-ADER Injection-Molded Tablets) vs Extended-Release Morphine Administered Intranasally in Nondependent Recreational Opioid Users

Objective. To compare the relative human abuse potential after insufflation of manipulated morphine abuse-deterrent, extended-release injection-molded tablets (morphine-ADER-IMT) with that of marketed morphine ER tablets.

Methods. A randomized, double-blind, double-dummy, active- and placebo-controlled five-way crossover study was performed with adult volunteers who were experienced, nondependent, recreational opioid users. After intranasal (IN) administration of manipulated high-volume (HV) morphine-ADER-IMT (60 mg), participants were randomized (1:1:1:1) to receive IN manipulated low-volume (LV) morphine ER (60 mg), IN manipulated LV morphine-ADER-IMT, intact oral morphine-ADER-IMT (60 mg), and placebo in crossover fashion. Pharmacodynamic and pharmacokinetic assessments included peak effect of drug liking (E_max; primary endpoint) using drug liking visual analog scale (VAS) score, E_max using overall drug liking, and take drug again (TDA) VASs scores, and mean abuse quotient (AQ), a pharmacokinetic parameter associated with drug liking.

Results. Forty-six participants completed the study. After insufflation of HV morphine-ADER-IMT and LV morphine-ADER-IMT, drug liking E_max was significantly lower (P < 0.0001) compared with IN morphine ER. Overall drug liking and TDA E_max values were significantly lower (P < 0.0001) after insufflation of HV morphine-ADER-IMT and LV morphine-ADER-IMT compared with IN morphine ER. Mean AQ was lower after insufflation of HV (9.2) and LV (2.3) morphine-ADER-IMT or ingestion of oral morphine-ADER-IMT (5.5) compared with insufflation of LV morphine ER (37.2).

Conclusions. All drug liking, take drug again, and abuse quotient endpoints support a significantly lower abuse potential with insufflation of manipulated morphine-ADER-IMT compared with manipulated and insufflated non-AD ER morphine.

Human abuse potential studies of abuse-deterrent opioids: lessons from oral and intranasal studies with morphine abuse-deterrent, extended-release, injection-molded tablets

BACKGROUND

The development and use of abuse-deterrent (AD) opioids is part of a multifaceted strategy to reduce misuse, abuse, and diversion, while maintaining access for patients with severe pain who may benefit from their analgesic efficacy. Morphine AD, extended-release (ER), injection-molded tablets (morphine-ADER-IMT; ARYMO ER; Egalet US Inc., Wayne, PA) is approved by the FDA as an AD opioid. As part of the characterization of AD opioids, assessments of their human abuse potential (HAP) are required. Evidence from HAP studies can guide clinicians on the use of AD opioids in clinical practice. Herein, we describe HAP study design, and how specific AD features can impact the conduct of a study and interpretation of its results.

OBJECTIVES

To review the design features and results of the oral and intranasal HAP studies with morphine-ADER-IMT in order to improve the understanding of key elements of HAP studies of AD opioids.

CONCLUSIONS

Results from HAP studies with morphine-ADER-IMT and other AD opioids suggest that key study design features include the release profile (immediate-release vs extended-release) of the positive control, study drug doses, and the way the products are manipulated. These elements can directly impact the outcomes of the pharmacokinetic and pharmacodynamic (e.g. Maximum Drug Liking, Overall Drug Liking, and Take Drug Again) results. When evaluating HAP studies, it is important to understand study design features to assist in the interpretation of the results and understand the clinical relevance of the data to help guide clinical decision-making about the use of AD opioids.

In Vitro Assessment of Nasal Insufflation of Comminuted Drug Products Designed as Abuse Deterrent Using the Vertical Diffusion Cell

In vitro evaluation of abuse deterrent formulations (ADFs) is a challenge since real abuse situations are variable and ADF technology is evolving. Specifically, an assessment of an ADF to deter nasal insufflation would be valuable. In this study, a vertical diffusion cell (VDC) was used to evaluate polyethylene oxide (PEO)-based tablets manipulated by three different forces. The commercially available products Oxycontin®, an ADF, Opana®, and metoprolol tartrate tablet formulations made in our laboratory were studied. Particle size distribution and percent recovery of manipulated tablets were measured. Grinding produced the lowest recovery and the smallest particle size distribution. Drug release was examined using a VDC by placing the dry comminuted particles on an enclosed wetted cellulose membrane. Dispensing dry particles on a VDC is atypical but includes some key features associated with an abuse situation where once the particles are snorted, the moisture in the nasal mucosa activates hydration and swelling of the polymers in the formulation, retarding drug release. Drug release from OxyContin®, Opana®, and metoprolol tablets were analyzed for the cutting, grinding, and milling modes of abuse. The analysis showed that in most cases, the mode of abuse produced different particle sizes with different release rates. Statistically different release rates were observed for metoprolol tablets made with different molecular weight PEO and with different porosities. These results indicate that within detection limits, the VDC can be used to quantitate release differences due to various modes of abuse used in this study.

Intranasal Pharmacokinetics of Morphine ARER, a Novel Abuse-Deterrent Formulation: Results from a Randomized, Double-Blind, Four-Way Crossover Study in Nondependent, Opioid-Experienced Subjects

Objective

To investigate the pharmacokinetics (PK) of Morphine ARER, an extended-release (ER), abuse-deterrent formulation of morphine sulfate after oral and intranasal administration.

Methods

This randomized, double-blind, double-dummy, placebo-controlled, four-way crossover study assessed the PK of morphine and its active metabolite, M6G, from crushed intranasal Morphine ARER and intact oral Morphine ARER compared with crushed intranasal ER morphine following administration to nondependent, recreational opioid users. The correlation between morphine PK and the pharmacodynamic parameter of drug liking, a measure of abuse potential, was also evaluated.

Results

Mean maximum observed plasma concentration (C_max) for morphine was lower with crushed intranasal Morphine ARER (26.2 ng/mL) and intact oral Morphine ARER (18.6 ng/mL), compared with crushed intranasal ER morphine (49.5 ng/mL). The time to C_max (T_max) was the same for intact oral and crushed intranasal Morphine ARER (1.6 hours) and longer for crushed intranasal morphine ER (1.1 hours). Higher mean maximum morphine C_max, T_max, and abuse quotient (C_max/T_max) were positively correlated with maximum effect for drug liking (R² ≥ 0.9795).

Conclusion

These data suggest that Morphine ARER maintains its ER profile despite physical manipulation and intranasal administration, which may be predictive of a lower intranasal abuse potential compared with ER morphine.

Blocking interleukin-4 enhances efficacy of vaccines for treatment of opioid abuse and prevention of opioid overdose

Vaccines offer an option to treat heroin and prescription opioid abuse and prevent fatal overdoses. Opioid vaccines elicit antibodies that block opioid distribution to the brain and reduce opioid-induced behavioral effects and toxicity. The major limitation to the translation of addiction vaccines is that efficacy is observed only in subjects achieving optimal drug-specific serum antibody levels. This study tested whether efficacy of a vaccine against oxycodone is increased by immunomodulators targeting key cytokine signaling pathways involved in B and T cell lymphocyte activation. Blockage of IL-4 signaling increased vaccine efficacy in blocking oxycodone distribution to the brain and protection against opioid-induced behavior and toxicity in mice. This strategy generalized to a peptide-protein conjugate immunogen, and a tetanus-diphtheria-pertussis vaccine. These data demonstrate that cytokine-based immunomodulators increase efficacy of vaccines against small molecules, peptides and proteins, and identify IL-4 as a pharmacological target for improving efficacy of next-generation vaccines.

Abuse-deterrent opioids: an update on current approaches and considerations

OBJECTIVE

Abuse and misuse of prescription opioids is a significant public health concern. This review examines the strategies used to confer abuse-deterrent properties on opioid abuse-deterrent formulations (ADFs), the characteristics and supporting data for each of the available ADFs, and the role of opioid ADFs as part of a comprehensive opioid risk management plan.

METHODS

A PubMed search was performed for articles published within the last 10 years using the search terms "abuse deterrent opioids". Articles were limited to clinical studies and reviews focusing on United States (US) Food and Drug Administration (FDA)-approved opioid ADFs in the US.

RESULTS

There are currently nine extended-release and one immediate-release opioid pain medications with US FDA-approved ADF labelling. All use either physical and chemical barriers or agonist/antagonist combinations to deter manipulation and abuse. Evidence is mounting that introduction of opioid ADFs has been associated with decreased rates of abuse and diversion of opioids in the US.

CONCLUSIONS

Although not sufficient by themselves to prevent prescription opioid abuse and misuse, opioid ADFs are an important component of a healthcare provider's comprehensive opioid risk management plan (along with utilization of prescription drug monitoring programs, clinical assessment tools, urine tests, co-prescribing of naloxone to patients at risk of an overdose, access to non-pharmacological treatments and addiction/mental health resources, among others). Adoption of opioid ADFs should be considered as part of an overall public health opioid risk management plan involving all stakeholders to balance legitimate safe and effective use of opioids against misuse and abuse.

Pharmacokinetics and -dynamics of intramuscular and intranasal naloxone: an explorative study in healthy volunteers

PURPOSE

This study aimed to develop a model for pharmacodynamic and pharmacokinetic studies of naloxone antagonism under steady-state opioid agonism and to compare a high-concentration/low-volume intranasal naloxone formulation 8 mg/ml to intramuscular 0.8 mg.

METHODS

Two-way crossover in 12 healthy volunteers receiving naloxone while receiving remifentanil by a target-controlled infusion for 102 min. The group were subdivided into three different doses of remifentanil. Blood samples for serum naloxone concentrations, pupillometry and heat pain threshold were measured.

RESULTS

The relative bioavailability of intranasal to intramuscular naloxone was 0.75. Pupillometry showed difference in antagonism; the effect was significant in the data set as a whole (p < 0.001) and in all three subgroups (p < 0.02-p < 0.001). Heat pain threshold showed no statistical difference.

CONCLUSIONS

A target-controlled infusion of remifentanil provides good conditions for studying the pharmacodynamics of naloxone, and pupillometry was a better modality than heat pain threshold. Intranasal naloxone 0.8 mg is inferior for a similar dose intramuscular. Our design may help to bridge the gap between studies in healthy volunteers and the patient population in need of naloxone for opioid overdose.

TRIAL REGISTRATION

clinicaltrials.gov : NCT02307721.

Opioid Dose- and Route-Dependent Efficacy of Oxycodone and Heroin Vaccines in Rats

Heroin and oxycodone abuse occurs over a wide range of drug doses and by various routes of administration characterized by differing rates of drug absorption. The current study addressed the efficacy of a heroin vaccine [morphine hapten conjugated to keyhole limpet hemocyanin (M-KLH)] or oxycodone vaccine [oxycodone hapten conjugated to keyhole limpet hemocyanin (OXY-KLH)] for reducing drug distribution to brain after intravenous heroin or oxycodone, or subcutaneous oxycodone. Rats immunized with M-KLH or keyhole limpet hemocyanin (KLH) control received an intravenous bolus dose of 0.26 or 2.6 mg/kg heroin. Vaccination with M-KLH increased retention of heroin and its active metabolites 6-acetylmorphine (6-AM) and morphine in plasma compared with KLH controls, and reduced total opioid (heroin + 6-AM + morphine) distribution to brain but only at the lower heroin dose. Immunization also protected against respiratory depression at the lower heroin dose. Rats immunized with OXY-KLH or KLH control received 0.22 or 2.2 mg/kg oxycodone intravenously, the molar equivalent of the heroin doses. Immunization with OXY-KLH significantly reduced oxycodone distribution to brain after either oxycodone dose, although the magnitude of effect of immunization at the higher oxycodone dose was small (12%). By contrast, vaccination with OXY-KLH was more effective when oxycodone was administered subcutaneously rather than intravenously, reducing oxycodone distribution to brain by 44% after an oxycodone dose of 2.3 mg/kg. Vaccination also reduced oxycodone-induced antinociception. These data suggest that the efficacy of OXY-KLH and M-KLH opioid vaccines is highly dependent upon opioid dose and route of administration.

The Abuse Potential of Prescription Opioids in Humans-Closing in on the First Century of Research

While opioids are very effective analgesics for treating acute pain, humans have struggled with opiate addiction for millenia. An opium abuse epidemic in the early 1900's led the US government to develop a systematic research infrastructure and scientific plan to produce new compounds with analgesic properties but without abuse liability. This review describes the techniques that were developed for testing in the human laboratory, including empirically derived outcome measures and required elements for human abuse potential assessment. The evaluation and characterization of semi-synthetic and synthetic opioids, including full mu opioid agonists, partial agonists and mixed agonist-antagonists, are described across several decades of research. Finally, the prescription opioid epidemic beginning in the 1990's in the US led to a resurgence in abuse potential evaluations, and the application of these methods to the study of novel abuse-deterrent formulations is discussed.

Oral Human Abuse Potential of Oxycodone DETERx® (Xtampza® ER)

Oxycodone DETERx^® (Collegium Pharmaceutical Inc, Canton, Massachusetts) is an extended‐release, microsphere‐in‐capsule, abuse‐deterrent formulation designed to retain its extended‐release properties after tampering (eg, chewing/crushing). This randomized, double‐blind, placebo‐controlled, triple‐dummy study evaluated the oral abuse potential of intact and chewed oxycodone DETERx capsules compared with crushed immediate‐release oxycodone. Subjects with a history of recreational opioid use who were nondependent/nontolerant to opioids were enrolled. Treatments included intact oxycodone DETERx (high‐fat, high‐calorie meal and fasted), chewed oxycodone DETERx (high‐fat, high‐calorie meal and fasted), crushed immediate‐release oxycodone (fasted), and placebo (high‐fat, high‐calorie meal). Plasma samples were collected to determine pharmacokinetic parameters. The primary endpoint was drug liking at the moment; other endpoints included drug effects questionnaire scores, Addiction Research Center Inventory/Morphine Benzedrine Group score, pupillometry measurements, and safety. Thirty‐eight subjects completed the study. Chewed and intact oxycodone DETERx were bioequivalent, unlike crushed immediate‐release oxycodone, which yielded higher peak oxycodone plasma concentrations compared with all methods of oxycodone DETERx administration. The mean maximum (peak) effect (E_max) for drug liking was significantly lower for chewed and intact oxycodone DETERx than for crushed immediate‐release oxycodone (P < .01). The time to E_max was significantly longer for chewed and intact oxycodone DETERx than for crushed immediate‐release oxycodone (P < .0001). Scores for feeling high and Addiction Research Center Inventory/Morphine Benzedrine Group scores demonstrated lower abuse potential for chewed and intact oxycodone DETERx compared with crushed immediate‐release oxycodone. Study treatments were well tolerated; no subjects experienced serious adverse events. These results demonstrate the lower oral abuse potential of chewed and intact oxycodone DETERx than crushed immediate‐release oxycodone.

Abuse-deterrent formulations of prescription opioid analgesics in the management of chronic noncancer pain

Misuse, abuse and diversion of prescription opioid analgesics represent a global public health concern. The development of abuse-deterrent formulations (ADFs) of prescription opioid analgesics is an important step toward reducing abuse and diversion of these medications, as well as potentially limiting medical consequences when misused or administered in error. ADFs aim to hinder extraction of the active ingredient, prevent administration through alternative routes and/or make abuse of the manipulated product less attractive, less rewarding or aversive. However, opioid ADFs may still be abused via the intended route of administration by increasing the dose and/or dosing frequency. The science of abuse deterrence and the regulatory landscape are still relatively new and evolving. This paper reviews the current status of opioid ADFs, with particular focus on different approaches that can be used to deter abuse, regulatory considerations and implications for clinical management.

The effect of an abuse-deterrent opioid formulation (OxyContin) on opioid abuse-related outcomes in the postmarketing setting

An extended‐release opioid analgesic (OxyContin, OC) was reformulated with abuse‐deterrent properties to deter abuse. This report examines changes in abuse through oral and nonoral routes, doctor‐shopping, and fatalities in 10 studies 3.5 years after reformulation. Changes in OC abuse from 1 year before to 3 years after OC reformulation were calculated, adjusted for prescription changes. Abuse of OC decreased 48% in national poison center surveillance systems, decreased 32% in a national drug treatment system, and decreased 27% among individuals prescribed OC in claims databases. Doctor‐shopping for OC decreased 50%. Overdose fatalities reported to the manufacturer decreased 65%. Abuse of other opioids without abuse‐deterrent properties decreased 2 years later than OC and with less magnitude, suggesting OC decreases were not due to broader opioid interventions. Consistent with the formulation, decreases were larger for nonoral than oral abuse. Abuse‐deterrent opioids may mitigate abuse and overdose risks among chronic pain patients.

How Resistant to Tampering are Codeine Containing Analgesics on the Market? Assessing the Potential for Opioid Extraction

Introduction

Misuse of opioid analgesics, in combination with diversion, dependence, and fatal overdoses, presents a serious problem for public health, which affects many countries worldwide. Within this context, tampering with opioids has been associated with serious harm. The aim of the present study was to assess the tampering potential of codeine combination analgesics on the market (containing codeine/non-opioid analgesics) by the extraction of codeine.

Methods

Codeine was extracted from three combination formulations sold lawfully from licensed pharmacies without a medical prescription in Denmark and the UK. Extraction of codeine followed tampering procedures available on the Internet. The amounts of codeine and accompanying non-opioid analgesics in tampering products were analysed with liquid chromatography and tandem mass spectrometry (LC–MS/MS).

Results

LC–MS/MS showed recoveries of the total amounts of codeine in tampering products of 81–84% from Product 1 (codeine/acetylsalicylic acid); 61–67% from Product 2 (codeine/ibuprofen); and 42–71% from Product 3 (codeine/paracetamol). Recoveries of non-opioid analgesics ranged between: 57–73% acetylsalicylic acid; 5.5–8.5% ibuprofen, and 5.0–9.2% paracetamol.

Conclusion

With the tampering procedures used, high amounts of codeine were separated from the accompanying analgesics in some, but not in all of the codeine containing formulations. Evidence-based medicine regulation, treatment for opioid dependence, and information to minimise risks to the public are essential components of an effective public health strategy to address the harms of tampering and misuse.

Funding

Marie Pedersen and Jensine Heiberg Foundation.

Gender difference in prescription opioid abuse: A focus on oxycodone and hydrocodone

Several data gathered in the last decade indicate an increase of abuse of prescription opioid drugs oxycodone (OXY) and hydrocodone (HYDRO) in women. However, to date there are no conclusive evidences investigating the gender-dependent abuse liability of prescription opioids. This study aims to supply a specific focus on women's data through a selective summary of the literature analyzing gender differences in the pharmacokinetic and pharmacodynamic dimension of OXY and HYDRO. Findings from this study suggest that the majority of OXY and HYDRO pharmacokinetic and pharmacodynamic effects do not differ according to gender, though confirming a significant difference in the incidence of adverse effects as demonstrated by the increased gastrointestinal adverse reactions in female subjects. Although the majority of recent clinical studies include an equal number of female and male subjects, the main outcome parameters do not relate specifically to gender differences. Due to the gender influence in activity of CYP3A4 and its crucial role in metabolism of both OXY than HYDRO, we suggest that assessing pharmacokinetic and pharmacodynamic interactions in clinical studies may be useful to clarify the effect of the higher CYP3A4 activity in female in relation to CYP2D6 genotype. Overall, considering the paucity of data regarding gender differences in European Union, this work highlights that impact of new abuse deterrent formulations should be assessed with a special focus on data concerning female subjects.

Understanding the magnitude of emergent contaminant releases through target screening and metabolite identification using high resolution mass spectrometry: Illicit drugs in raw sewage influents

A QExactive Orbitrap was used for the identification of phase I and II transformation products (TPs) of illicit drugs in raw sewage influents. Two operating modes (targeted MS(2) and Data-dependent screening) were used for data acquisition. Even though, data-dependent scan is a faster route towards the potential identification of metabolites, it suffered from its limitation to provide enough data points across the chromatographic peak during the MS(2) cycle in contrast to targeted MS(2). Therefore, the later technique was implemented as the method of choice in this study for the positive confirmation and quantitation of TPs (n=54). The vast majority of the identified TPs were products of phase I transformation reactions, with the latter being more prevalent in the nature. Estimated mole fractions showed that for a large number of the analytes, TPs must also be monitored in order to fully understand their environmental fate and calculate potential consumption.

Impact of abuse-deterrent OxyContin on prescription opioid utilization

PURPOSE

We quantified the degree to which the August 2010 reformulation of abuse-deterrent OxyContin affected its use, as well as the use of alternative extended-release and immediate-release opioids.

METHODS

We used the IMS Health National Prescription Audit, a nationally representative source of prescription activity in the USA, to conduct a segmented time-series analysis of the use of OxyContin and other prescription opioids. Our primary time period of interest was 12 months prior to and following August 2010. We performed model checks and sensitivity analyses, such as adjusting for marketing and promotion, using alternative lag periods, and adding extra observation points.

RESULTS

OxyContin sales were similar before and after the August 2010 reformulation, with approximately 550 000 monthly prescriptions. After adjusting for declines in the generic extended-release oxycodone market, the formulation change was associated with a reduction of approximately 18 000 OxyContin prescription sales per month (p = 0.02). This decline corresponded to a change in the annual growth rate of OxyContin use, from 4.9% prior to the reformulation to -23.8% during the year after the reformulation. There were no statistically significant changes associated with the sales of alternative extended-release (p = 0.42) or immediate-release (p = 0.70) opioids. Multiple sensitivity analyses supported these findings and their substantive interpretation.

CONCLUSIONS

The market debut of abuse-deterrent OxyContin was associated with declines in its use after accounting for the simultaneous contraction of the generic extended-release oxycodone market. Further scrutiny into the effect of abuse-deterrent formulations on medication use and health outcomes is vital given their popularity in opioid drug development.