Assessing the subjective and physiological effects of intranasally administered crushed extended-release morphine formulations with and without a sequestered naltrexone core in recreational opioid users

A survey of drug liking and cravings in patients using sublingual or intranasal ketamine for treatment resistant depression: A preliminary evaluation of real world addictive potential

Ketamine has gained rapid popularity as a treatment option for treatment resistant depression (TRD). Though seen only in limited contexts, ketamine is a potential drug of abuse, addiction and diversion. Clinical ketamine studies to date have not systematically evaluated factors relevant to addiction risk in patients with TRD, but in treating patients with ketamine, risks of potential harms related to addiction must be considered. As clinical access to intravenous ketamine programs is limited in much of Canada, these considerations become even more important for clinicians who elect to offer patients less supervised, non-parenteral forms of ketamine treatment. This study explores factors relevant to addiction risk in a real-world sample of 33 patients with TRD currently or previously treated with sublingual (SL) or intranasal (IN) ketamine in the community. First, patients were surveyed using a Drug Liking and Craving Questionnaire (DLCQ) to assess their level of drug liking and craving for ketamine, and to screen for symptoms of a ketamine use disorder. Second, the pharmacy records of these patients were reviewed for red flags for addiction such as dose escalation or early refills. Third, surveys were administered to the treating psychiatrists of patients who had discontinued ketamine to determine if abuse concerns contributed to reason for discontinuation. Though limited to a small sample, results indicate that ketamine is not a universally liked or craved substance in patients with TRD. Prescribers of non-parenteral ketamine should monitor patients and prescribe cautiously. Factors related to addiction (as in the DLCQ) should be explored for clinicians to consider individual risk/benefit for judicious use of ketamine in patients with TRD.

Abuse-deterrent properties and cytotoxicity of poly(ethylene oxide) after thermal tampering

Poly(ethylene oxide) (PEO) is the most common deterring agent used in the abuse-deterrent formulations (ADFs). In this study, we investigated the PEO's abuse-deterrent properties and its potential cytotoxicity after being heated at high temperatures (80 °C and 180 °C). The results indicated a significant loss in both crush and extraction resistance features of the polymer, which is primarily associated with the polymer degradation at the higher temperatures. The heat-treated PEO at the high temperature was also found to lose its controlled-release feature, upon which over 80% of the drug was released after one hour in the simulated gastric fluid. The cytotoxicity of the PEO was further assessed to evaluate the safety of the polymer following the thermal treatment. Our findings revealed a substantial loss in the viability of the cells exposed to the PEO treated at higher temperatures. Taken all, heating PEO at high temperatures can lead to a significant loss in both the crush/extraction resistance characteristics and the safety of the polymer. These findings reemphasize the fact that more appropriate and stricter test and regulations will be needed to assure that the abuse deterrent formulations are safe and effective under severe conditions of abuse.

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.

Extended-release morphine sulfate and naltrexone hydrochloride (EMBEDA): naltrexone-associated withdrawal and abuse-related effects in patients with chronic pain and recreational opioid users

OBJECTIVE

To review the effects of naltrexone on withdrawal-related adverse events (AEs) and euphoria-related effects, and the relationship between plasma naltrexone concentrations and withdrawal across EMBEDA (MSN; extended-release morphine sulfate with sequestered naltrexone) studies.

METHODS

Five studies in pain patients and a safety review summarizing AE reports during the first year following approval of MSN were assessed for withdrawal reports. Three of these studies also assessed Clinical Opiate Withdrawal Scale (COWS) scores. Plasma naltrexone concentrations of MSN-treated individuals were summarized. Abuse potential was assessed in four studies in non-dependent recreational opioid users.

RESULTS

Withdrawal AEs occurred in 13/1781 patients across five MSN studies, and 25/182 cases involving withdrawal were reported in the safety review. In three of these studies, 11/964 patients experienced moderate withdrawal (COWS score = 13-24) and 1/964 patients experienced moderately severe withdrawal (score = 28); all were either non-compliant with study drug, had undetectable plasma naltrexone concentrations, or were tapering to placebo. In ≥89% of plasma naltrexone concentration samples from patients who took MSN (n = 166), naltrexone was below the limit of quantification (4.0 pg/mL). In four studies with non-dependent recreational opioid users (n = 118), crushed MSN was associated with significantly lower scores of drug liking, high, and take drug again than crushed morphine sulfate (p ≤ 0.005).

CONCLUSIONS

When taken intact as directed, naltrexone in MSN does not precipitate withdrawal. However, when MSN is crushed, naltrexone mitigates, but does not eliminate, the euphorigenic effects of crushed morphine sulfate.

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.

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.

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.

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

PURPOSE

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

METHODS

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

FINDINGS

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

IMPLICATIONS

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

Pharmacokinetic and pharmacodynamic evaluation of oxycodone and naltrexone for the treatment of chronic lower back pain

INTRODUCTION

Chronic low back pain (CLBP) is a common and difficult illness to manage. Some individuals with CLBP have pain processing disorders and are also at risk for opioid abuse, misuse; addiction and diversion. Guidelines have been published to guide management; neuromodulation, exercise, mindfulness-based stress reduction and cognitive behavior therapies among other non-pharmacological reduce the pain of CLBP with minimal toxicity. Pharmacological management includes acetaminophen, NSAIDs and antidepressants, mainly duloxetine. Abuse-deterrent opioids have been developed which have been shown to reduce pain and opioid abuse risk. ALO-02 is a tamper-resistant sustained release opioid consisting of extended release oxycodone and sequestered naltrexone. Pivotal studies of ALO-02 have centered on patients with CLBP.

AREAS COVERED

This manuscript will review CLBP, the pivotal analgesic and clinical abuse potential studies of ALO-02. The opinion will cover whether opioids should be used for CLBP, when they should be used and opioid choices.

EXPERT OPINION

ALO-02 is one of several opioids which can be considered in the management of CLBP. The outcome to a trial of opioids should be function rather than analgesia. Most analgesic trials for CLBP have had analgesia as the primary outcome and function has not been vigorously studied as an outcome. Opioids should be considered as a trial only when other non-opioid analgesics have failed to improve analgesia and function. Universal precautions should be routinely part of phase III analgesic trial particularly for chronic non-malignant pain.

A randomized double-blind, placebo-controlled efficacy and safety study of ALO-02 (extended-release oxycodone surrounding sequestered naltrexone) for moderate-to-severe chronic low back pain treatment

The objective of this multicenter, double-blind, placebo-controlled, randomized withdrawal study was to evaluate the efficacy and safety of ALO-02, an abuse-deterrent formulation containing pellets of extended-release oxycodone hydrochloride (HCl) surrounding sequestered naltrexone HCl, compared with placebo in the treatment of moderate-to-severe chronic low back pain. An open-label titration period in which all patients received ALO-02 was followed by a double-blind treatment period where patients meeting treatment response criteria were randomized to either a fixed dose of ALO-02 or placebo. Daily average low back pain was assessed using an 11-point numeric rating scale (NRS)-Pain. Of the 663 patients screened, 410 received ALO-02 during the open-label conversion and titration period and 281 patients were randomized to the double-blind treatment period (n = 134, placebo; n = 147, ALO-02). Change in the mean NRS-Pain score from randomization baseline to the final 2 weeks of the treatment period was significantly different favoring ALO-02 compared with placebo (P = 0.0114). Forty-four percent of patients treated with placebo and 57.5% of patients treated with ALO-02 reported ≥30% improvement in weekly average NRS-Pain scores from screening to the final 2 weeks of the treatment period (P = 0.0248). In the double-blind treatment period, 56.8% of patients in the ALO-02 group and 56.0% of patients in the placebo group experienced a treatment-emergent adverse event (TEAE). The most common treatment-related TEAEs for ALO-02 during the treatment period were nausea, vomiting, and constipation, consistent with opioid therapy. ALO-02 has been demonstrated to provide significant reduction of pain in patients with chronic low back pain and has a safety profile similar to other opioids.

Safety profile of extended-release morphine sulfate with sequestered naltrexone hydrochloride in older patients: pooled analysis of three clinical trials

OBJECTIVE

Clinical trial safety data following chronic administration of extended-release opioids within an older population is limited. Embeda * is an extended-release formulation of morphine sulfate surrounding sequestered naltrexone hydrochloride (MSN) and is designed to deter opioid misuse and abuse. The present analysis compared pooled safety outcomes among patients aged ≥65 years and those aged <65 years from three phase 2/3 studies (ranging from 2 weeks to 12 months) in patients treated with MSN.

RESEARCH DESIGN AND METHODS

Subgroup analysis of patients aged ≥65 years and <65 years was performed on pooled data for adverse events (AEs), potentially clinically significant laboratory values (hematology/chemistry), and signs/symptoms of opioid withdrawal using the Clinical Opiate Withdrawal Scale (COWS) (phase 3 trials only) for patients who received at least one dose (short-term studies, maximum dose was 160 mg/d or 320 mg/d depending on study; long-term study, no maximum dose) of study medication during titration and maintenance phases.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT00420992, NCT00415597.

RESULTS

During titration, 173 (17.1%) of 1012 patients treated with MSN were aged ≥65 years, while during maintenance 76/564 (13.5%) patients were aged ≥65 years. Treatment-emergent AEs were similar in frequency and type between the two cohorts, with the most common being constipation, nausea, and somnolence; no consistent patterns relating to age and only one possibly treatment-related serious AE in patients ≥65 years was noted. No clinically significant differences in laboratory values or COWS scores (average maximum score ≤2.5) were observed between age groups.

CONCLUSIONS

Safety outcomes following daily administration of MSN (2 weeks-12 months) were similar between patients aged ≥65 years and <65 years. Key limitations include the variable study designs and length of treatment (2 weeks-12 months), small sample size, and the inclusion of only those patients who were otherwise in relatively good health with restrictions on concomitant medications.

A multicenter, primary-care-based, open-label study to assess the success of converting opioid-experienced patients with chronic moderate-to-severe pain to morphine sulfate and naltrexone hydrochloride extended-release capsules using a standardized conversion guide

OBJECTIVE

To evaluate the conversion of opioid-experienced patients with chronic moderate-to-severe pain to extended-release morphine sulfate with sequestered naltrexone hydrochloride (MSN) using a standardized conversion guide.

METHODS

This open-label, single-arm study was conducted in 157 primary care centers in the United States. A total of 684 opioid-experienced adults with chronic moderate-to-severe pain were converted to oral administration of MSN from transdermal fentanyl and oral formulations of hydrocodone, hydromorphone, methadone, oxycodone, oxymorphone, and other morphine products using a standardized conversion guide. The primary endpoint was the percentage of patients achieving a stable MSN dose within a 6-week titration phase. Secondary endpoints included duration of time to stable dose, number of titration steps, safety and efficacy measures, and investigator assessment of conversion guide utility.

RESULTS

Of the 684 patients, 51.3% were converted to a stable dose of MSN (95% confidence interval: 47.5%, 55.1%). The mean (standard deviation) number of days to stable dose was 20 (8.94), and number of titration steps to stable dose was 2.4 (1.37). The majority of adverse events were mild/moderate and consistent with opioid therapy. Mean pain scores at stable dose decreased from baseline. Investigators were generally satisfied with the conversion guide and, in 94% of cases, reported they would use it again.

CONCLUSION

Conversion to MSN treatment using the standardized MSN conversion guide was an attainable goal in approximately half of the population of opioid-experienced patients with chronic moderate-to-severe pain. Investigators found the guide to be a useful tool to assist conversion of opioid-experienced patients to MSN.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.