Abuse risks and routes of administration of different prescription opioid compounds and formulations

RGS9-2 Modulates Responses to Oxycodone in Pain-Free and Chronic Pain States

Regulator of G-protein signaling 9-2 (RGS9-2) is a striatal-enriched signal-transduction modulator known to have a critical role in the development of addiction-related behaviors following exposure to psychostimulants or opioids. RGS9-2 controls the function of several G-protein-coupled receptors, including dopamine receptor and mu opioid receptor (MOR). We previously showed that RGS9-2 complexes negatively control morphine analgesia, and promote the development of morphine tolerance. In contrast, RGS9-2 positively modulates the actions of other opioid analgesics, such as fentanyl and methadone. Here we investigate the role of RGS9-2 in regulating responses to oxycodone, an MOR agonist prescribed for the treatment of severe pain conditions that has addictive properties. Using mice lacking the Rgs9 gene (RGS9KO), we demonstrate that RGS9-2 positively regulates the rewarding effects of oxycodone in pain-free states, and in a model of neuropathic pain. Furthermore, although RGS9-2 does not affect the analgesic efficacy of oxycodone or the expression of physical withdrawal, it opposes the development of oxycodone tolerance, in both acute pain and chronic neuropathic pain models. Taken together, these data provide new information on the signal-transduction mechanisms that modulate the rewarding and analgesic actions of oxycodone.

A tale of 2 ADFs: differences in the effectiveness of abuse-deterrent formulations of oxymorphone and oxycodone extended-release drugs

The introduction of extended-release opioid analgesics helped initiate an epidemic of prescription opioid abuse in the United States. To make access to the drug by crushing or dissolution more difficult, abuse-deterrent formulations (ADFs) of OxyContin (Purdue Pharma, Stamford, CT) and Opana ER (Endo Pharmaceuticals Inc., Malvern, PA), which use the same foundation technology (Intac, Grunenthal, Aachen, Germany), were introduced in 2010 and 2012, respectively. To examine their relative effectiveness, we used a structured survey of 12,124 individuals entering treatment for opioid use disorder followed by a more focused online survey with a subset of these patients (N = 129) using both structured and open-ended questions. Data showed that the OxyContin ADF was highly effective in reducing nonoral abuse (91.4% before the ADF, 47.9% afterwards), particularly with insufflation (78%-28.8%) and intravenous injection of the active drug (42.7%-21.4%). However, although the Opana ER ADF was effective in reducing insufflation (80%-37.1%), injection (60.0%-51.4%), and overall nonoral abuse (94.3%-77.1%), it showed no significant decrease over time. Bearing in mind that the Opana ER sample was smaller in size than that for OxyContin, our results nonetheless suggest disparate outcomes resulting from the introduction of the ADFs, which could indicate that an ADF's effectiveness may be drug-specific. Given the public health impact of prescription opioids and the considerable effort being expended to develop ADFs as a partial solution to the problem, our preliminary studies suggest that each ADF must be evaluated on its own merits even if the same proprietary technology is used.

Assessing the impact of abuse-deterrent opioids (ADOs): identifying epidemiologic factors related to new entrants with low population exposure

OBJECTIVE

Prescription opioid misuse and abuse is a serious public health concern that can lead to overdose, addiction, and death. The development of opioid formulations designed to deter misuse and abuse is considered an important step towards addressing the problem, but the extent to which abuse-deterrent opioids (ADOs) actually deter abuse in the community requires confirmation through epidemiologic studies. Epidemiologic evaluations of misuse and abuse present several unique challenges related to study design, sources of data, and methodology, particularly for new entrant ADOs with low population exposure. The purpose of this article is to review the critical methodologic issues that must be considered when designing an epidemiologic evaluation of prescription opioid misuse and abuse, and deterrence for new entrant ADOs.

METHODS

A systematic feasibility assessment was conducted by critically evaluating and applying epidemiologic principles to combinations of epidemiology study design, study directionality, population, data source, clinical and patient-reported endpoints, type of comparator, effect size, and the ability to control for confounding variables.

RESULTS

Ten epidemiologic factors were identified that are considered key to an epidemiologic evaluation, and the issues associated with each are summarized.

CONCLUSION

Given the low population exposure of new entrant ADOs, there is limited feasibility in conducting the epidemiologic studies necessary to evaluate the effectiveness of these products in deterring abuse. Clear regulatory guidance is needed.

Abuse and Diversion of Immediate Release Opioid Analgesics as Compared to Extended Release Formulations in the United States

BACKGROUND

Therapeutic use and abuse of prescription opioids in the United States increased substantially between 1990 and 2010. The Centers for Disease Control estimated deaths related to pharmaceutical opioids reached nearly 19,000 in 2014. Of prescription opioids sold, 10% are extended release (ER) and 90% immediate release (IR). However, most regulations and interventions have focused on decreasing ER abuse. Our objective was to compare rates of abuse and diversion of ER and IR opioid analgesics over time using multiple surveillance programs.

METHODS

Rates of abuse and diversion of ER and IR opioid formulations were compared using data from four surveillance programs in the Researched Abuse, Diversion and Addiction Related Surveillance (RADARS®) System. Data were evaluated from 2009 through 2015, and Poisson regression used to compare IR and ER opioid cases over time.

RESULTS

From 2009 to 2015, IR opioids were prescribed at a rate 12 to 16 times higher than ER. In the Poison Center Program, population-adjusted rates of Intentional Abuse for IR were 4.6 fold higher than ER opioids (p<0.001). In the Drug Diversion Program, population-adjusted rates of diversion were 6.1 fold higher for IR than ER opioids (p<0.001). In the Opioid Treatment Program, population-adjusted rates of endorsements for abuse were 1.6 fold higher for IR opioids than ER (p = 0.002). In the Survey of Key Informants' Patients Program, population-adjusted rates of endorsements for abuse were 1.5 fold higher for IR opioids than ER (p<0.001).

CONCLUSIONS

Between 2009 and 2015, IR opioids were prescribed at a much higher rate than ER opioids. Results from four surveillance programs show population-adjusted rates of prescription opioid abuse were markedly higher for IR than ER medications. For the greatest public health benefit, future interventions to decrease prescription opioid abuse should focus on both IR and ER formulations.

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.

Decreased diversion by doctor-shopping for a reformulated extended release oxycodone product (OxyContin)

BACKGROUND

Doctor-shopping (obtaining prescriptions from multiple prescribers/pharmacies) for opioid analgesics produces a supply for diversion and abuse, and represents a major public health issue.

METHODS

An open cohort study assessed changes in doctor-shopping in the U.S. for a brand extended release (ER) oxycodone product (OxyContin) and comparator opioids before (July, 2009 to June, 2010) versus after (January, 2011 to June, 2013) introduction of reformulated brand ER oxycodone with abuse-deterrent properties, using IMS LRx longitudinal data covering >150 million patients and 65% of retail U.S. prescriptions.

RESULTS

After its reformulation, the rate of doctor-shopping decreased 50% (for 2+ prescribers/3+ pharmacies) for brand ER oxycodone, but not for comparators. The largest decreases in rates occurred among young adults (73%), those paying with cash (61%) and those receiving the highest available dose (62%), with a 90% decrease when stratifying by all three characteristics. The magnitude of doctor-shopping reductions increased with increasing number of prescribers/pharmacies (e.g., 75% reduction for ≥2 prescribers/≥4 pharmacies).

CONCLUSIONS

The rate of doctor-shopping for brand ER oxycodone decreased substantially after its reformulation, which did not occur for other prescription opioids. The largest reductions in doctor-shopping occurred with characteristics associated with higher abuse risk such as youth, cash payment and high dose, and with more specific thresholds of doctor-shopping. A higher prescriber and/or pharmacy threshold also increased the magnitude of the decrease, suggesting that it better captured the effect of the reformulation on actual doctor-shoppers.

Prescription Opioids. V. Metabolism and Excretion of Oxymorphone in Urine Following Controlled Single Dose Administration

Oxymorphone (OM), a prescription opioid and metabolite of oxycodone, was included in the recently published proposed revisions to the Mandatory Guidelines for Federal Workplace Drug Testing Programs. To facilitate toxicological interpretation, this study characterized the time course of OM and its metabolite, noroxymorphone (NOM), in hydrolyzed and non-hydrolyzed urine specimens. Twelve healthy subjects were administered a single 10 mg controlled-release OM dose, followed by a periodic collection of pooled urine specimens for 54 h following administration. Analysis for free and total OM and NOM was conducted by liquid chromatography tandem mass spectrometry (LC-MS-MS), at a 50 ng/mL limit of quantitation (LOQ). Following enzymatic hydrolysis, OM and NOM were detected in 89.9% and 13.5% specimens, respectively. Without hydrolysis, OM was detected in 8.1% specimens, and NOM was not detected. The mean ratio of hydrolyzed OM to NOM was 41.6. OM was frequently detected in the first pooled collection 0-2 h post-dose, appearing at a mean of 2.4 h. NOM appeared at a mean of 8.3 h. The period of detection at the 50 ng/mL threshold averaged 50.7 h for OM and 11.0 h for NOM. These data support that OM analysis conducted using a 50 ng/mL threshold should include hydrolysis or optimize sensitivity for conjugated OM.

Conversations about analgesics in the emergency department: A qualitative study

OBJECTIVE

We sought to characterize conversations about analgesics in the Emergency Department (ED) setting.

METHODS

A secondary analysis of 47 audio-recorded ED visits containing conversations about analgesics was performed. Data were collected at an urban, academic medical center among adults with one of four diagnoses. Visit transcripts were analyzed qualitatively using content and constant comparative analysis. The speaker, medication being discussed, and overall conversation concordance were categorized.

RESULTS

Among the 47 transcripts there were 1102 unique statements related to analgesics. Thirteen codes were identified; however, four codes (discussing details of administration, forecasting, side effects, past history) accounted for over 65% of the conversations. Patient requests, statements related to chronic pain and contentious conversations occurred infrequently, but were present (17% discordant conversations, 83% concordant). Medical providers dominated the conversations with patients' contributions equaling only a quarter of total coded conversation.

CONCLUSIONS

These findings characterize the narrow range of topics discussed about analgesics and demonstrate that many risks of opioid medications were not discussed.

PRACTICE IMPLICATIONS

Increased counseling about opioids may be warranted given rising opioid-related deaths. To be prepared, providers may wish to reflect on how to approach different topics related to opioids and analgesia prior to engaging in such discussions.

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.

A Randomized, Double-Blind, Double-Dummy Study to Evaluate the Intranasal Human Abuse Potential and Pharmacokinetics of a Novel Extended-Release Abuse-Deterrent Formulation of Oxycodone

OBJECTIVE

Evaluate the human abuse potential (HAP) of an experimental, microsphere-in-capsule formulation of extended-release oxycodone (oxycodone DETERx®) (herein "DETERx").

DESIGN

Randomized, double-blind, double-dummy, positive- and placebo-controlled, single-dose, four-phase, four-treatment, crossover study.

SETTING

Clinical research site.

SUBJECTS

There were 39 qualifying subjects (72% male, 85% white, mean age of 27 years) with 36 completing all four Double-blind Treatment Periods.

METHODS

The four phases encompassed: 1) Screening; 2) Drug Discrimination; 3) Double-blind Treatment; and 4) Follow-up. Drug Discrimination tests ensured that subjects could distinguish placebo from opioid. The four Double-blind Treatments compared DETERx-administered as either a crushed intranasal (IN) or an intact oral (PO) preparation-with immediate-release oxycodone IN (OXY-IR IN) and with an intact IN and PO placebo DETERx control.

RESULTS

For primary pharmacokinetic (PK) assessments, abuse quotient (Cmax/Tmax) was lower with DETERx IN than DETERx PO; both treatments were substantially lower than OXY-IR IN (6.24, 8.60, and 69.6 ng/mL/h, respectively). For drug liking, the primary subjective pharmacodynamic (PD) endpoint, both DETERx IN and DETERx PO produced significantly lower scores than OXY-IR IN (P ≤ 0.0001 for each); DETERx IN was less liked than DETERx PO (P ≤ 0.05), mirroring the PK relationships. Objectively assessed pupillometry corroborated the more rapid and significantly greater effect of OXY-IR IN than either DETERx IN or DETERx PO (P ≤ 0.007 for each). Overall safety profiles of DETERx and OXY-IR were comparable and both were well tolerated.

CONCLUSIONS

Pharmacokinetic and pharmacodynamic outcomes suggest that DETERx IN has relatively low HAP; continued research in larger populations is suggested.

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.

Correlation of Subjective Effects with Systemic Opioid Exposure from Fixed-Dose Combinations of Oxycodone/Acetaminophen in Recreational Users of Prescription Drugs

OBJECTIVE

To correlate abuse-related pharmacodynamic measures and pharmacokinetic measures after administering immediate-release/extended-release and immediate-release oxycodone/acetaminophen fixed-dose combination analgesicsDesign. Randomized, double-blind, active- and placebo-controlled, 7-way crossover studySetting. Contract research organizationSubjects. Nondependent recreational users of prescription opioids.

METHODS

Participants received single doses of intact immediate-release/extended-release and immediate-release oxycodone/acetaminophen 15/650 mg, intact immediate-release/extended-release and immediate-release oxycodone/acetaminophen 30/1,300 mg, crushed immediate-release/extended-release and immediate-release oxycodone/acetaminophen 30/1,300 mg, and placebo. Measures of pharmacodynamics (pupillometry, drug liking, drug high, good drug effects) and pharmacokinetics were assessed predose and up to 24 hours postdose, and correlations between pharmacokinetic parameters and pharmacodynamic data were explored.

RESULTS

Of 61 participants, 55 completed all 7 treatments. Intact immediate-release/extended-release oxycodone/acetaminophen produced 50% lower oxycodone peak plasma concentration (C_max) than immediate-release oxycodone/acetaminophen. Median oxycodone time to C_max (t_max) was significantly longer (P<0.001) for intact immediate-release/extended-release oxycodone/acetaminophen than immediate-release oxycodone/acetaminophen. The pharmacokinetics of crushed immediate-release/extended-release and immediate-release oxycodone/acetaminophen (30/1,300 mg) followed a similar pattern. Crushing did not shorten the median oxycodone t_max for immediate-release/extended-release oxycodone/acetaminophen (30/1,300 mg). Strong correlations were observed between oxycodone C_max and area under the curve from time 0 to time x peak effects and area under the subjective effect curve from time 0 to time x for all subjective effects (R²=0.711-0.997).

CONCLUSION

Immediate-release/extended-release oxycodone/acetaminophen produced lower oxycodone C_max and longer t_max than immediate-release oxycodone/acetaminophen. Lower oxycodone concentrations, particularly at earlier time points, were strongly correlated with lesser positive subjective drug effects.

Abuse potential of intravenous oxycodone/naloxone solution in nondependent recreational drug users

BACKGROUND AND OBJECTIVE

Abuse of opioid analgesics has become a public health issue. Some opioid abusers use intravenous administration to increase the magnitude of positive reinforcing effects. Intravenous co-administration of oxycodone with naloxone, an opioid antagonist, may reduce these rewarding effects and discourage abuse. A 2:1 oxycodone:naloxone (OXN) tablet formulation has been studied in the USA for the management of moderate-to-severe chronic pain. Intravenous administration of a 2:1 oxycodone:naloxone solution (sOXN) reflects the oxycodone:naloxone ratio found in laboratory studies of OXN following tampering for intravenous administration. The objective of this study was to characterize abuse-deterrent properties of sOXN.

METHODS

This single-center, double-blind, randomized, placebo-controlled, active-controlled, crossover study enrolled nondependent recreational opioid users with experience using multiple (two or more) routes of administration. Following demonstration that subjects could discern between placebo and oxycodone, 24 eligible male and female subjects were randomized to receive intravenous injections of 0.07 mg/kg oxycodone (OXY), 0.07 mg/kg oxycodone and 0.035 mg/kg naloxone solution (sOXN), or matching placebo over three visits. Pharmacokinetics, pharmacodynamics, safety, and tolerability were assessed at scheduled times up to 8 h post-dose. Parameters were computed and statistically compared among treatments.

RESULTS

Pharmacokinetics were similar between OXY and sOXN. Subjects reported significantly fewer rewarding effects with sOXN compared with OXY; differences between sOXN and placebo were generally not significant. sOXN was well tolerated.

CONCLUSIONS

Significant reductions in drug liking and other subjective effects following administration of sOXN compared with OXY indicate that naloxone concentrations were sufficient to antagonize the effects of oxycodone when abused by the intravenous route of administration in opioid-experienced drug users.

Effects of oxycodone on brain responses to emotional images

RATIONALE

Evidence from animal and human studies suggests that opiate drugs decrease emotional responses to negative stimuli and increase responses to positive stimuli. Such emotional effects may motivate misuse of oxycodone (OXY), a widely abused opiate. Yet, we know little about how OXY affects neural circuits underlying emotional processing in humans.

OBJECTIVE

We examined effects of OXY on brain activity during presentation of positive and negative visual emotional stimuli. We predicted that OXY would decrease amygdala activity to negative stimuli and increase ventral striatum (VS) activity to positive stimuli. Secondarily, we examined the effects of OXY on other emotional network regions on an exploratory basis.

METHODS

In a three-session study, healthy adults (N = 17) received placebo, 10 and 20 mg OXY under counterbalanced, double-blind conditions. At each session, participants completed subjective and cardiovascular measures and underwent functional MRI (fMRI) scanning while completing two emotional response tasks.

RESULTS

Our emotional tasks reliably activated emotional network areas. OXY produced subjective effects but did not alter either behavioral responses to emotional stimuli or activity in our primary areas of interest. OXY did decrease right medial orbitofrontal cortex (MOFC) responses to happy faces.

CONCLUSIONS

Contrary to our expectations, OXY did not affect behavioral or neural responses to emotional stimuli in our primary areas of interest. Further, the effects of OXY in the MOFC would be more consistent with a decrease in value for happy faces. This may indicate that healthy adults do not receive emotional benefits from opiates, or the pharmacological actions of OXY differ from other opiates.

Comparison of subjective effects of extended-release versus immediate-release oxycodone/acetaminophen tablets in healthy nondependent recreational users of prescription opioids: a randomized trial

BACKGROUND

Prescription opioids have substantial abuse potential. This study compared the positive subjective drug effects of a newly developed extended-release (ER) oxycodone (OC)/acetaminophen (acetyl-para-aminophenol [APAP]) formulation with those of immediate-release (IR) OC/APAP.

METHODS

This randomized, double-blind, active- and placebo-controlled, 7-way crossover study enrolled healthy volunteers who were recreational prescription opioid users. The protocol was approved by an institutional review board and all participants provided written informed consent. Participants received single doses of intact ER and IR OC/APAP 15/650 mg, intact ER and IR OC/APAP 30/1300 mg, crushed ER and IR OC/APAP 30/1300 mg, and placebo. Peak subjective effects (Emax), time to Emax, and area under the drug-effect curves for drug liking, drug high, and good drug effects were measured using visual analogue scales. Least squares means with 95% confidence interval were compared using analysis of variance.

RESULTS

Among completers (N = 55), intact ER OC/APAP produced delayed and lower peak effects versus IR OC/APAP. Comparing intact tablets, the drug liking Emax (least squares means [95% confidence interval]) was significantly lower for OC/APAP 30/1300 mg (76.4 [72.8 to 80.0]) than for IR OC/APAP 30/1300 mg (85.6 [81.9 to 89.2]; difference, -9.2 [-13.1 to -5.2]; P < 0.001). Similar results were observed for intact ER and IR OC/APAP (15 mg/650 mg). Crushing ER OC/APAP 30/1300 mg further delayed these effects compared with the same dose of crushed IR OC/APAP and intact ER OC/APAP.

CONCLUSIONS

Extended-release OC/APAP produced lower subjective drug effects than IR OC/APAP. Crushing ER OC/APAP further delayed onset of subjective effects compared with intact ER OC/APAP. The ER OC/APAP may be less attractive for abuse than IR OC/APAP.

CLINICAL TRIAL REGISTRATION

This phase 1 study conducted in the United States was not registered.

Reductions in reported deaths following the introduction of extended-release oxycodone (OxyContin) with an abuse-deterrent formulation

Purpose

Abuse of opioid analgesics for their psychoactive effects is associated with a large number of fatalities. The effect of making opioid tablets harder to crush/dissolve on opioid-related fatalities has not been assessed. The objective of this study was to assess the impact of introducing extended-release oxycodone (ERO [OxyContin®]) tablets containing physicochemical barriers to crushing/dissolving (reformulated ERO) on deaths reported to the manufacturer.

Methods

All spontaneous adverse event reports of death in the US reported to the manufacturer between 3Q2009 and 3Q2013 involving ERO were used. The mean numbers of deaths/quarter in the 3 years after reformulated ERO introduction were compared with the year before. Changes in the slope of trends in deaths were assessed using spline regression. Comparison groups consisted of non-fatal reports involving ERO and fatality reports involving ER morphine.

Results

Reports of death decreased 82% (95% CI: −89, −73) from the year before to the third year after (131 to 23 deaths per year) reformulation; overdose death reports decreased 87% (95% CI: −93, −78) and overdose deaths with mention of abuse-related behavior decreased 86% (95% CI:−92, −75). In contrast, non-fatal ERO reports did not decrease post-reformulation, and reported ER morphine fatalities remained unchanged. The ratio of ERO fatalities to all oxycodone fatalities decreased from 21% to 8% in the year pre-reformulation to the second year post-reformulation.

Conclusions

These findings, when considered in the context of previously published studies using other surveillance systems, suggest that the abuse-deterrent characteristics of reformulated ERO have decreased the fatalities associated with its misuse/abuse. © 2014 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons, Ltd.

Development and impact of prescription opioid abuse deterrent formulation technologies

BACKGROUND

Millions of patients are treated with opioid analgesics (OpAs) to relieve pain. Unfortunately, these medications are subject to abuse and/or unintended misuse. Abuse deterrent formulations (ADFs) represent an intervention strategy to decrease abuse/misuse without affecting patient access. The Food and Drug Administration (FDA) has issued Draft Guidance "Abuse deterrent opioids, Evaluation and Labeling" and is currently actively pursuing scientific input on this issue.

METHODS

The development of ADF technologies was reviewed using peer reviewed journals describing OpA post marketing studies, web sites containing FDA announcements on product approvals and manufacturer product use profiles.

RESULTS

Reviewed is the FDA recent approval of a product label describing the abuse deterrent characteristics of OxyContin(®) (physical barrier formulation), and the FDA determination that studies were insufficient for an Opana(®) (physical barrier) ADF label. Additional reviewed marketed OpAs with ADF technologies include: Suboxone(®) and Embeda(®) (opioid agonist/antagonist combinations), Oxecta(®) (aversion technology), and Nucynta(®) (physical barrier). Reviewed ADF technologies currently in development include: new physical barrier and aversion technologies, an innovative extended release formulation as well as novel polymer-opioid conjugates. As ADF technologies are part of a comprehensive intervention strategy to promote safe OpA use, additional components including governmental, community, and educational initiatives are reviewed.

CONCLUSIONS

The outcomes of the recent ADF labeling applications for OxyContin(®) (Tier 3 approval) and Opana(®) (non-approval) suggest that the threshold for ADF labeling will be appropriately high. The presented findings indicate that ADF technologies can be a critical component of a comprehensive strategy to promote the safe and effective use of OpAs.

Tamper-resistant opioid formulations in the treatment of acute pain

INTRODUCTION

Pain-including acute or persistent acute pain-is a common condition that is increasingly being treated with opioids in the United States. The acute pain treatment setting may represent a key target for addressing the growing epidemic of prescription drug abuse occurring hand in hand with the rise in opioid prescribing. Balancing the needs of pain treatment with abuse prevention can be challenging for clinicians.

METHODS

This article identified efforts to balance opioid abuse risks with opioid availability through the extensive experience of the author in this field. In addition, PubMed literature searches using terms such as "prescription opioid abuse", "abuse-deterrent opioids", and "tamper-resistant opioids"; and inspection of the bibliographies of relevant articles were used to identify relevant sources.

RESULTS

These multifaceted efforts have included: improving assessment of patient risk for drug misuse, abuse, or diversion; funding of and encouraging referral to addiction treatment programs; access to and widespread use of prescription monitoring programs (PMPs); public knowledge of prescription opioid abuse; proper storage of opioid medications; and development of new formulations designed to resist tampering and deter abuse. This review discusses the problem of prescription opioid abuse and strategies to minimize risk within the context of acute pain treatment, and explores the potential role of tamper-resistant opioid formulations and other abuse deterrence strategies in the area of acute or persistent acute pain management.

CONCLUSION

In order to stem the tide of prescription opioid abuse and preserve the availability of opioids as a much needed analgesic option, a multifaceted approach that includes tamper-resistant opioid formulations-for chronic or acute pain-along with strategies such as improved patient risk assessment, funding for and referral to addiction treatment programs, greater use of PMPs, and raised awareness of prescription opioid abuse is needed.

Nonmedical prescription drug users in private vs. public substance abuse treatment: a cross sectional comparison of demographic and HIV risk behavior profiles

Background

Little is known regarding the demographic and behavioral characteristics of nonmedical prescription drug users (NMPDUs) entering substance abuse treatment settings, and information on the HIV-related risk profiles of NMPDUs is especially lacking. Participation in substance abuse treatment provides a critical opportunity for HIV prevention and intervention, but successful initiatives will require services appropriately tailored for the needs of NMPDUs.

Methods

This paper compares the HIV risk profiles of NMPDUs in public (n = 246) and private (n = 249) treatment facilities. Participants included in the analysis reported five or more recent episodes of nonmedical prescription drug use, a prior HIV negative test result, and current enrollment in a substance abuse treatment facility. A standardized questionnaire was administered by trained interviewers with questions about demographics, HIV risk, and substance use.

Results

Private treatment clients were more likely to be non-Hispanic White, younger, and opioid and heroin users. Injection drug use was higher among private treatment clients, whereas public clients reported higher likelihood of trading or selling sex. Public treatment clients reported higher rates of HIV testing and availability at their treatment facilities compared to private clients.

Conclusions

Findings suggest differing demographics, substance use patterns, profiles of HIV risk and access to HIV testing between the two treatment samples. Population tailored HIV interventions, and increased access to HIV testing in both public and private substance treatment centers, appear to be warranted.

Current topics in opioid therapy for pain management: addressing the problem of abuse

Opioids are an established therapy for cancer pain and have become an accepted therapy for chronic noncancer pain. However, increased prescribing of opioids in recent years has been accompanied by an increase in prescription opioid abuse. All opioids have inherent potential for abuse, but gaps in healthcare provider understanding of or adherence to best prescribing practices may facilitate the misdirection of opioids for abuse. To address these concerns, the US Food and Drug Administration has required pharmaceutical manufacturers to develop Risk Evaluation and Mitigation Strategies (REMS) for prescribers of extended-release/long-acting (ER/LA) opioids and has encouraged research to develop opioid formulations that are less easily abused or less attractive for abuse. The ER/LA opioid REMS require a partnership between the pharmaceutical industry, regulators, and healthcare providers to develop educational materials for physicians and patients that are not promotional. This article addresses challenges associated with improving the quality of pain care through support of prescriber education, developing formulations that combine efficacy with tamper-resistant properties, and encouraging collaborative efforts by regulatory bodies, legislators, healthcare providers, and patient advocacy groups to achieve these ends.

Formulation optimization of hot-melt extruded abuse deterrent pellet dosage form utilizing design of experiments

OBJECTIVE

The objective of this study was to develop techniques for an abuse-deterrent (AD) platform utilizing the hot-melt extrusion (HME) process.

METHODS

Formulation optimization was accomplished by utilizing Box-Behnken design of experiments to determine the effect of the three formulation factors: PolyOx WSR301, Benecel K15M and Carbopol 71G; each of which was studied at three levels on tamper-resistant (TR) attributes of the produced melt extruded pellets. A response surface methodology was utilized to identify the optimized formulation. Lidocaine hydrochloride was used as a model drug, and suitable formulation ingredients were employed as carrier matrices and processing aids.

KEY FINDINGS

All of the formulations were evaluated for the TR attributes, such as particle size post-milling, gelling and percentage of drug extraction in water and alcohol. All of the design of experiments formulations demonstrated sufficient hardness and elasticity, and could not be reduced into fine particles (<150 μm), which is a desirable feature to prevent snorting. In addition, all of the formulations exhibited good gelling tendency in water with minimal extraction of drug in the aqueous medium. Moreover, Benecel K15M, in combination with PolyOx WSR301, could be utilized to produce pellets with TR potential.

CONCLUSION

HME has been demonstrated to be a viable technique with a potential to develop novel AD formulations.

End-of-dose pain in chronic pain: does it vary with the use of different long-acting opioids?

A large percentage of patients with chronic pain on around-the-clock (ATC) opioids may experience increased pain occurring at the end of a scheduled dose, also known as end-of-dose pain. Despite the significant prevalence and impact of end-of-dose pain in patients using extended-release (ER) opioids, there are no detailed analyses examining how the frequency of end-of-dose pain is linked to the formulations of long-acting opioids. Consequently, we performed a systematic review to evaluate how many published studies on patients with chronic cancer or noncancer pain identified end-of-dose pain. As only a few studies mentioned end-of-dose pain explicitly, we used breakthrough pain (BTP) as a surrogate parameter. We determined if any opioid formulation had a greater association with the frequency of BTP, the use of rescue medication for BTP, and the frequency of end-of-dose pain. Of the 39 studies entered in the final analysis, 14 studies across different formulations showed that ER opioids were effective in the prevention of BTP. The opioids most frequently studied were hydromorphone (26%), followed by morphine (23%), and transdermal buprenorphine (23%). Only 5% of the studies used immediate-release preparations. Overall, most studies showed that patients using ER preparations experienced fewer episodes of BTP compared with patients on placebo or an active comparator. This could reflect the favorable duration of action of these opioids compared with short-acting formulations. Future studies should examine the incidence of end-of-dose pain and use of rescue medicine in a longitudinal manner in patients with chronic pain taking short- vs. long-acting ATC opioids.

Changes in prevalence of prescription opioid abuse after introduction of an abuse-deterrent opioid formulation

OBJECTIVE

The reformulation of oxycodone hydrochloride controlled-release (CR) tablets in August 2010 created a natural experiment at a national scale, providing an opportunity to evaluate patterns of abuse of prescription opioids and other drugs before and after introduction of this abuse-deterrent formulation (ADF).

DESIGN

Observational, cross-sectional study

SETTING

Sentinel sample of adults assessed for substance abuse treatment within the NAVIPPRO® surveillance system

SUBJECTS

Two hundred thirty-two thousand and eight hundred seventy-four adults at 437 facilities during January 1, 2008 through December 31, 2011.

METHODS

Time-series analysis using logistic regression to estimate quarterly prevalence of past 30-day abuse (adjusted for covariates and prescription volume) and changes in abuse pre-and post-ADF introduction.

RESULTS

Increases in abuse prevalence occurred for all prescription opioids as a class and for extended-release (ER) opioids. Significantly greater abuse of ER oxymorphone and buprenorphine occurred in the post-ADF period (relative risk [RR] = 2.91, 95% confidence interval [CI] = 2.59-3.27 and RR = 1.85, 95% CI = 1.74-1.96). Increases in abuse for these two compounds were significant among groups who reported abuse via preferential routes of administration (oral only, snorting only, injection only) post-ADF introduction.

CONCLUSIONS

Replacement of a widely prescribed opioid formulation known for its abuse potential alone may have had little impact on overall rates of prescription opioids as a class. However, changes in abuse levels of certain opioids coinciding with ADF introduction suggest possible switching of abuse among this study sample to specific long-acting opioid analgesics. Additional follow-up studies will be important to monitor changing abuse patterns and their public health impact as new opioid formulations are developed and introduced to market.

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.

Changes in oxycodone and heroin exposures in the National Poison Data System after introduction of extended-release oxycodone with abuse-deterrent characteristics

PURPOSE

Abuse and misuse of prescription opioids are serious public health problems. Abuse-deterrent formulations are an intervention to balance risk mitigation with appropriate patient access. This study evaluated the effects of physicochemical barriers to crushing and dissolving on safety outcomes associated with extended-release oxycodone (ERO) tablets (OxyContin) using a national surveillance system of poison centers. Other single-entity (SE) oxycodone tablets and heroin were used as comparators and to assess substitution effects.

METHODS

The National Poison Data System covering all US poison centers was used to measure changes in exposures in the year before versus the 2 years after introduction of reformulated ERO (7/2009-6/2010 vs 9/2010-9/2012). Outcomes included abuse, therapeutic errors affecting patients, and accidental exposures.

RESULTS

After ERO reformulation, abuse exposures decreased 36% for ERO, increased 20% for other SE oxycodone, and increased 42% for heroin. Therapeutic errors affecting patients decreased 20% for ERO and increased 19% for other SE oxycodone. Accidental exposures decreased 39% for ERO, increased 21% for heroin, and remained unchanged for other SE oxycodone. During the study period, other interventions to reduce opioid abuse occurred, for example, educational and prescription monitoring programs. However, these have shown small effects and do not explain a drop for ERO exposures but not for other opioids.

CONCLUSIONS

After ERO reformulation, calls to poison centers involving abuse, therapeutic errors affecting patients, and accidental exposures decreased for ERO, but not for comparator opioids. Abuse-deterrent formulations of opioid analgesics can reduce abuse, but switching to other accessible non abuse-deterrent opioids might occur.

Hydromorphone: evolving to meet the challenges of today's health care environment

BACKGROUND

Hydromorphone, a potent analogue of morphine, has long had an important role in pain management and is included in several international guidelines for managing pain. Advances in hydromorphone formulations and the ways in which hydromorphone is being used clinically today warrant a review of the drug's pharmacotherapeutic utility.

OBJECTIVE

The history and recent advances in hydromorphone pharmacotherapy are reviewed. Areas covered include the pharmacologic and metabolic profile of hydromorphone, the role of hydromorphone in pain management, formulations and routes of administration, and issues related to relative opioid potencies, equianalgesic ratios, and opioid rotation. Because hydromorphone, like all opioids, carries a risk of misuse, abuse, and illicit diversion, the related issues of tamper-resistant formulations and "dose-dumping" of extended-release formulations are discussed.

CONCLUSIONS

Due to the epidemic of prescription opioid overdoses associated with prescription opioid abuse in the United States, development of tamper-resistant opioid formulations that avoid dose-dumping issues has become a significant goal of pharmaceutical manufacturers. The current formulation of hydromorphone extended-release potentially provides the benefits of long-acting hydromorphone (ie, continuous pain control, increased quality of life, freedom to perform daily activities) to appropriate patients, while reducing the risks of abuse and without compromising safety.

Using poison center exposure calls to predict prescription opioid abuse and misuse-related emergency department visits

BACKGROUND

Prescription drug abuse is a critical problem in the USA and has been linked to more deaths than automobile accidents. Despite this growing epidemic, the USA lacks a timely early warning system. Poison centers (PCs) have the potential to act as sentinel reporting entities for prescription drug abuse and misuse due to near-real-time data reporting and abundant coverage in the USA.

METHODS

Data from the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS®) System PC program were compared with data from the Drug Abuse Warning Network (DAWN) from 2004 through 2010. Population rates of PC call mentions regarding abuse and misuse of prescription opioids were compared with population rates of emergency department visit mentions of the same using linear regression. Products included in the analysis were the following: buprenorphine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, and oxycodone.

RESULTS

The strength of association between RADARS System PC data and DAWN emergency department visits regarding all opioids in aggregate was strong (R² = 0.81, p < 0.001). The correlations between the two programs at the drug class level also were strong for buprenorphine, hydrocodone, hydromorphone, methadone, and oxycodone (all R² > 0.70, all p < 0.01), significant for fentanyl (p = 0.05), and moderate for morphine (p = 0.09).

CONCLUSIONS

Data on prescription opioid drug abuse from the RADARS System PC program correlates well with emergency room data from DAWN. Due to timeliness of data, geographic coverage and strong associations with other warning systems, PC data can be used for sentinel reporting on prescription drug abuse and misuse in the USA.

Attractiveness of reformulated OxyContin(R) tablets: assessing comparative preferences and tampering potential

Reformulated OxyContin® (oxycodone HCl controlled-release or ORF) was developed as a tamper and abuse-deterrent product, to reduce the risk of product abuse, misuse and their consequences. This noninterventional single-session study asked participants who were medically-healthy recreational opioid users, aged 18 years and older, to consider how they would use commonly available supplies to tamper with placebo ORF and placebo original OxyContin (OC) tablets, and how they would assess the attractiveness of tampering and abusing ORF tablets, as compared with other opioid formulations. Participants provided information on past opioid use, and they assessed the properties of five nonhypothetical oxycodone products and two hypothetical oxycodone products. Participants provided feedback on tampering preferences, preferred tamper methods for each product, overall tampering potential and product preferences. We had 30 participants (27 males and 3 females; mean age 35 years, range 18-51) complete both the interview and tampering sessions. Participants judged OC as the most attractive, valuable, desirable and most likely to be tampered with, from among all opioid products studied. By contrast, they rated ORF as the least attractive, least valuable, least desirable, and least likely to be tampered with among all the nonhypothetical opioid products studied. These results suggested that recreational drug abusers view ORF tablets as tamper-deterrent products.