Pharmacologic treatments for opioid dependence: detoxification and maintenance options

Pannexin-1 channel inhibition alleviates opioid withdrawal in rodents by modulating locus coeruleus to spinal cord circuitry

Opioid withdrawal is a liability of chronic opioid use and misuse, impacting people who use prescription or illicit opioids. Hyperactive autonomic output underlies many of the aversive withdrawal symptoms that make it difficult to discontinue chronic opioid use. The locus coeruleus (LC) is an important autonomic centre within the brain with a poorly defined role in opioid withdrawal. We show here that pannexin-1 (Panx1) channels expressed on microglia critically modulate LC activity during opioid withdrawal. Within the LC, we found that spinally projecting tyrosine hydroxylase (TH)-positive neurons (LCspinal) are hyperexcitable during morphine withdrawal, elevating cerebrospinal fluid (CSF) levels of norepinephrine. Pharmacological and chemogenetic silencing of LCspinal neurons or genetic ablation of Panx1 in microglia blunted CSF NE release, reduced LC neuron hyperexcitability, and concomitantly decreased opioid withdrawal behaviours in mice. Using probenecid as an initial lead compound, we designed a compound (EG-2184) with greater potency in blocking Panx1. Treatment with EG-2184 significantly reduced both the physical signs and conditioned place aversion caused by opioid withdrawal in mice, as well as suppressed cue-induced reinstatement of opioid seeking in rats. Together, these findings demonstrate that microglial Panx1 channels modulate LC noradrenergic circuitry during opioid withdrawal and reinstatement. Blocking Panx1 to dampen LC hyperexcitability may therefore provide a therapeutic strategy for alleviating the physical and aversive components of opioid withdrawal.

Patient Engagement in and Adaptations to Delivery of Outpatient Care for Opioid Use Disorder During the COVID-19 Pandemic

OBJECTIVE

The authors investigated adaptations to outpatient care delivery and changes in treatment demand and engagement among patients receiving medications for opioid use disorder (MOUD) in the months after the declaration of the COVID-19 public health emergency in 2020.

METHODS

Data were collected through an online survey (June-November 2020) of outpatient MOUD prescribers. The survey obtained information on outpatient practices' adaptations to MOUD treatment and urine drug screening (UDS) and elicited provider views on the effects of the COVID-19 pandemic on patient demand for, and engagement in, treatment. Multivariable regression analyses were used to examine associations among practice characteristics, patient engagement, and service adaptations.

RESULTS

Of 516 respondents, 74% reported adaptations to MOUD delivery during the pandemic. Most respondents implemented virtual visits for initial (67%) and follow-up (77%) contacts. Prescribers of buprenorphine were more likely than those who did not prescribe the medication to report MOUD adaptations. Among respondents reporting any MOUD adaptation, 77% made adaptations to their UDS practices. Among 513 respondents who answered COVID-19-related questions, 89% reported that the pandemic had affected the treatment and engagement of their patients. Of these respondents, 30% reported increased difficulty with patient engagement, and 45% reported that their patients preferred virtual visits during this period, whereas 18% endorsed patient preference for in-person visits.

CONCLUSIONS

Telehealth and federal regulatory easements in response to the COVID-19 pandemic enabled providers to continue treating patients for opioid use disorder in 2020. The results suggest that care adaptations and changes in patient demand and engagement were common in the practices surveyed.

The Effect of Prenatal and Neonatal Fluoride Exposure to Morphine-Induced Neuroinflammation

Physical dependence is associated with the formation of neuroadaptive changes in the central nervous system (CNS), both at the molecular and cellular levels. Various studies have demonstrated the immunomodulatory and proinflammatory properties of morphine. The resulting neuroinflammation in drug dependence exacerbates substance abuse-related behaviors and increases morphine tolerance. Studies prove that fluoride exposure may also contribute to the development of neuroinflammation and neurodegenerative changes. Morphine addiction is a major social problem. Neuroinflammation increases tolerance to morphine, and neurodegenerative effects caused by fluoride in structures related to the development of dependence may impair the functioning of neuronal pathways, change the concentration of neurotransmitters, and cause memory and learning disorders, which implies this element influences the development of dependence. Therefore, our study aimed to evaluate the inflammatory state of selected brain structures in morphine-dependent rats pre-exposed to fluoride, including changes in cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) expression as well as microglial and astroglial activity via the evaluation of Iba1 and GFAP expression. We provide evidence that both morphine administration and fluoride exposure have an impact on the inflammatory response by altering the expression of COX-1, COX-2, ionized calcium-binding adapter molecule (Iba1), and glial fibrillary acidic protein (GFAP) in brain structures involved in dependence development, such as the prefrontal cortex, striatum, hippocampus, and cerebellum. We observed that the expression of COX-1 and COX-2 in morphine-dependent rats is influenced by prior fluoride exposure, and these changes vary depending on the specific brain region. Additionally, we observed active astrogliosis, as indicated by increased GFAP expression, in all brain structures of morphine-dependent rats, regardless of fluoride exposure. Furthermore, the effect of morphine on Iba1 expression varied across different brain regions, and fluoride pre-exposure may influence microglial activation. However, it remains unclear whether these changes are a result of the direct or indirect actions of morphine and fluoride on the factors analyzed.

Waiting times disparities for medication-assisted therapy among opioid use disorder treatment population in the United States

Opioid use disorder (OUD) treatment has been described as beneficial in reducing the burden of OUD and its related complications. Thus far, there is a paucity of literature on the time-to-treatment differences from the period of seeking treatment to when the patient starts treatment. Hence, it is deemed a form of barrier to the accessibility of OUD treatment programs. We aim to study the relationship between accessibility for medication-assisted treatment and the disparity concerning days waiting to enter OUD treatment. The treatment episode data set (TEDS) was utilized for this study. The full sample of 2018 TEDS-D (N = 382,547) is representative of OUD patients that utilized SUD treatment facilities within the 50 states of the United States. Univariate and multivariable logistic analysis of the independent variables, and other covariates with the dependent variables were explored to estimate the adjusted odds ratio relationship. Medication-assisted opioid therapy use among respondents was significantly different with waiting 1-7 days [AOR = 1.321 (95% CI = 1.248-1.400)] and >7 days [AOR = 0.729 (95% CI = 0.665-0.799)] to enter OUD treatment compared to waiting for less than a day. Among adults seeking OUD treatment admissions, our study showed that waiting times vary with MAT use as there was early entry compared to >1week wait time. Similarly, significant associations were reported across different sociodemographic attributes except for biological sex.

Case report: The lesson from opioid withdrawal symptoms mimicking paraganglioma recurrence during opioid deprescribing in cancer pain

Pain is one of the predominant and troublesome symptoms that burden cancer patients during their whole disease trajectory: adequate pain management is a fundamental component of cancer care. Opioid are the cornerstone of cancer pain relief therapy and their skillful management must be owned by physicians approaching cancer pain patients. In light of the increased survival of cancer patients due to advances in therapy, deprescription should be considered as a part of the opioid prescribing regime, from therapy initiation, dose titration, and changing or adding drugs, to switching or ceasing. In clinical practice, opioid tapering after pain remission could be challenging due to withdrawal symptoms' onset. Animal models and observations in patients with opioid addiction suggested that somatic and motivational symptoms accompanying opioid withdrawal are secondary to the activation of stress-related process (mainly cortisol and catecholamines mediated). In this narrative review, we highlight how the lack of validated guidelines and tools for cancer patients can lead to a lower diagnostic awareness of opioid-related disorders, increasing the risk of developing withdrawal symptoms. We also described an experience-based approach to opioid withdrawal, starting from a case-report of a symptomatic patient with a history of metastatic pheochromocytoma-paraganglioma.

Advances in the characterization of negative affect caused by acute and protracted opioid withdrawal using animal models

Opioid use disorder (OUD) is a chronic brain disease which originates from long-term neuroadaptations that develop after repeated opioid consumption and withdrawal episodes. These neuroadaptations lead among other things to the development of a negative affect, which includes loss of motivation for natural rewards, higher anxiety, social deficits, heightened stress reactivity, an inability to identify and describe emotions, physical and/or emotional pain, malaise, dysphoria, sleep disorders and chronic irritability. The urge for relief from this negative affect is one of major causes of relapse, and thus represents a critical challenge for treatment and relapse prevention. Animal models of negative affect induced by opioid withdrawal have recapitulated the development of a negative emotional state with signs such as anhedonia, increased anxiety responses, increased despair-like behaviour and deficits in social interaction. This research has been critical to determine neurocircuitry adaptations during chronic opioid administration or upon withdrawal. In this review, we summarize the recent literature of rodent models of (i) acute withdrawal, (ii) protracted abstinence from passive administration of opioids, (iii) withdrawal or protracted abstinence from opioid self-administration. Finally, we describe neurocircuitry involved in acute withdrawal and protracted abstinence. This article is part of the Special Issue on "Opioid-induced changes in addiction and pain circuits".

Targeting Opioid Receptors in Addiction and Drug Withdrawal: Where Are We Going?

This review article offers an outlook on the use of opioids as therapeutics for treating several diseases, including cancer and non-cancer pain, and focuses the analysis on the opportunity to target opioid receptors for treating opioid use disorder (OUD), drug withdrawal, and addiction. Unfortunately, as has been well established, the use of opioids presents a plethora of side effects, such as tolerance and physical and physiological dependence. Accordingly, considering the great pharmacological potential in targeting opioid receptors, the identification of opioid receptor ligands devoid of most of the adverse effects exhibited by current therapeutic agents is highly necessary. To this end, herein, we analyze some interesting molecules that could potentially be useful for treating OUD, with an in-depth analysis regarding in vivo studies and clinical trials.

Public transport access to drug treatment before and during COVID-19: Implications for the opioid epidemic

Public transport disruptions caused by the COVID-19 pandemic had wide-ranging impacts on the ability of individuals to access health care. Individuals with opioid use disorder represent an especially vulnerable population due to the necessity of frequent, supervised doses of opioid agonists. Focused on Toronto, a major Canadian city suffering from the opioid epidemic, this analysis uses novel realistic routing methodologies to quantify how travel times to individuals\220 nearest clinics changed due to public transport disruptions from 2019 to 2020. Individuals seeking opioid agonist treatment face very constrained windows of access due to the need to manage work and other essential activities. We find that thousands of households in the most materially and socially deprived neighbourhoods crossed 30 and 20-minute travel time thresholds to their nearest clinic. As even small changes to travel times can lead to missed appointments and heighten the chances of overdose and death, understanding the distribution of those most impacted can help inform future policy measures to ensure adequate access to care.

How do patients feel during the first 72 h after initiating long-acting injectable buprenorphine? An embodied qualitative analysis

BACKGROUND AND AIMS

Long-acting injectable buprenorphine (LAIB) is a new treatment for opioid use disorder that is generating positive outcomes. Negative effects are typically mild and transient, but can occasionally be serious, resulting in treatment discontinuation/non-adherence. This paper aims to analyse patients' accounts of how they felt during the first 72 h after initiating LAIB.

METHODS

Semi-structured interviews were conducted (June 2021-March 2022) with 26 people (18 males and 8 females) who had started LAIB within the previous 72 h. Participants were recruited from treatment services in England and Wales and were interviewed by telephone using a topic guide. Interviews were audio-recorded, transcribed and coded. The concepts of embodiment and embodied cognition framed the analyses. Data on participants' substance use, initiation onto LAIB and feelings were tabulated. Next, participants' accounts of how they felt were analysed following the stages of Iterative Categorization.

RESULTS

Participants reported complex combinations of changing negative and positive feelings. Bodily experiences included withdrawal symptoms, poor sleep, injection-site pain/soreness, lethargy and heightened senses inducing nausea ('distressed bodies'), but also enhanced somatic wellbeing, improved sleep, better skin, increased appetite, reduced constipation and heightened senses inducing pleasure ('returning body functions'). Cognitive responses included anxiety, uncertainties and low mood/depression ('the mind in crisis') and improved mood, greater positivity and reduced craving ('feeling psychologically better'). Whereas most negative effects reported are widely recognized, the early benefits of treatment described are less well-documented and may be an overlooked distinctive feature of LAIB.

CONCLUSIONS

During the first 72 h after initiating long-acting injectable buprenorphine, new patients report experiencing a range of interconnected positive and negative short-term effects. Providing new patients with information about the range and nature of these effects can prepare them for what to expect and help them manage feelings and reduce anxiety. In turn, this may increase medication adherence.

A randomized, sham-controlled, quintuple-blinded trial to evaluate the NET device as an alternative to medication for promoting opioid abstinence

Background

There is an unmet need for non-medication approaches to illicit opioid discontinuation and relapse prevention. The NET (NeuroElectric Therapy) Device is a non-invasive, battery-operated, portable, re-useable device designed to deliver bilateral transcranial transcutaneous alternating current electrical stimulation, and is intended to treat opioid use disorder (OUD) without medication. The device is a CE-marked Class IIa, non-significant risk, investigational medical device.

Objective

This prospective trial (NRC021) tests the hypothesis that the NET Device provides safe and effective neurostimulation treatment for persons with OUD who express a desire to be opioid abstinent without medications for opioid use disorder (MOUD).

Methods

NRC021 is a randomized, parallel-group, sham-controlled, quintuple-blinded, single-site study. Persons with OUD entering a residential treatment facility for opioid detoxification are assigned to active or sham treatment (n = 50/group). Group assignment is stratified on presence of any current non-opioid substance use disorder and by sex. The biostatistician maintains the blinding so that the study sponsor, principal investigator, research assistants, treatment staff, and participants remain blinded. Following discharge from the inpatient facility, participants are assessed once weekly over 12 weeks for substance use (using timeline followback interview and video assessment of observed oral fluid sample provision and testing). The primary efficacy endpoint is each participant's overall percentage of weekly abstinence from illicit opioid use without use of MOUD. The secondary efficacy endpoint is each participant's percentage of non-opioid drug-free weeks. Safety outcomes are also measured.

Conclusion

NRC021 is designed to assess the efficacy of a novel non-medication treatment for OUD.

Clinical trial registration

ClinicalTrials.gov with the identifier NCT04916600.

Pharmacotherapy of Opioid Use Disorder-Update and Current Challenges

The incidence of opioid use disorder (OUD) and overdose deaths is rising yearly within the United States. Many cases are associated with illicitly manufactured fentanyl use. In addition to offering patients medications for OUD (methadone, buprenorphine, and naltrexone), the approach to this epidemic should involve increasing provider awareness and education about substance use disorders, expanding urine toxicology screens to test for fentanyl, and using low-threshold treatment approaches.

Opioid Use Disorder and Older Adults: Navigating Treatment Options

The intent of the current article is to highlight via a case vignette challenges faced when managing pain across care transitions in an older adult with multiple comorbidities, including, but not limited to, opioid use disorder (OUD). This case will highlight the role of different medications for OUD, namely buprenorphine/naloxone, methadone, and naltrexone. Furthermore, the case illustrates medication-related considerations in addition to action steps that are needed when working with older adults. [Journal of Gerontological Nursing, 48(7), 4-9.].

Mobile Narcotic Treatment Programs: On the Road Again?

Many Americans with opioid use disorder (OUD), do not have access to treatment. Mobile narcotic treatment programs are now under new regulations that may make treatment more accessible to more people. These mobile programs can help expand the reach of opioid agonist treatment for OUD, help reduce human immunodeficiency viruses (HIV) and hepatitis C in the OUD population, and have retention rates that are often better than those at fixed-site clinics. Mobile services can also help reach marginalized individuals, the homeless, rural communities, and other underserved communities. They may offer methadone or buprenorphine treatment. Such mobile services have been used inside and outside the United States with promising results. In particular, mobile programs can make treatment available to people who do not have insurance, who lack reliable transportation, live in chaotic situations, or may be undomiciled. The potential pairing of mobile programs together with technology, such as smartphone apps or online resources, may allow mobile patients to benefit from counseling as well. Mobile clinics must be attached to a fixed-site narcotic treatment program and may have limitations with respect to the geographic area served. Mobile programs must have policies and procedures to store, transport, deliver, account for, reconcile, and dispose of opioid waste and would be subject to audit. Mobile opioid agonist therapy is an important and innovative service of particular value to underserved communities.

Managing Subarachnoid Hemorrhage Precipitated by Anesthesia-assisted Rapid Opioid Detoxification: A Case Report

INTRODUCTION

Anesthesia-assisted rapid opioid detoxification (AAROD) is a controversial method of treating opioid dependence that involves sedating patients during a period of provoked withdrawal. Reported adverse outcomes of the procedure demonstrate the importance of recognizing the potential complications of AAROD.

CASE PRESENTATION

We present a case of a 41-year-old male presenting with a subarachnoid hemorrhage following an AAROD procedure.

CONCLUSION

This case report and discussion reviews the pathophysiology of opioid withdrawal syndrome, potential complications following AAROD, and important management considerations.

Chronic heroin use disorder and the brain: Current evidence and future implications

The incidence of chronic heroin use disorder, including overdose deaths, has reached epidemic proportions. Here we summarise and evaluate our knowledge of the relationship between chronic heroin use disorder and the brain through a narrative review. A broad range of areas was considered including causal mechanisms, cognitive and neurological consequences of chronic heroin use and novel neuroscience-based clinical interventions. Chronic heroin use is associated with limited or very limited evidence of impairments in memory, cognitive impulsivity, non-planning impulsivity, compulsivity and decision-making. Additionally, there is some evidence for certain neurological disorders being caused by chronic heroin use, including toxic leukoencephalopathy and neurodegeneration. However, there is insufficient evidence on whether these impairments and disorders recover after abstinence. Whilst there is a high prevalence of comorbid psychiatric disorders, there is no clear evidence that chronic heroin use per se causes depression, bipolar disorder, PTSD and/or psychosis. Despite the growing burden on society from heroin use, knowledge of the long-term effects of chronic heroin use disorder on the brain remains limited. Nevertheless, there is evidence for progress in neuroscience-based interventions being made in two areas: assessment (cognitive assessment and neuroimaging) and interventions (cognitive training/remediation and neuromodulation). Longitudinal studies are needed to unravel addiction and neurotoxic mechanisms and clarify the role of pre-existing psychiatric symptoms and cognitive impairments.

The Effect of Adding Memantine to Clonidine in Reducing Withdrawal Symptoms in Opioid-Dependent Patients: A Double-Blind Randomized Controlled Trial

OBJECTIVE

Addiction is a complex condition and a brain disease manifested by compulsive substance use despite its harmful consequence. Addicted individuals have an intense focus on using substances. This study aimed to investigate the effect of adding memantine to clonidine and buprenorphine in reducing withdrawal symptoms, compared with placebo, in drug-dependent patients (opium and heroin).

MATERIALS AND METHODS

In this double-blind, randomized clinical trial study, 60 patients using opium or heroin were assigned to the intervention (n = 30) and control (n = 30) groups. Both groups were treated with buprenorphine and clonidine at the same dose in the detoxification process. The intervention group received memantine 10 mg daily for 10 days and then 20 mg daily for 21 days, and the control group received a placebo prepared in the same shape and size as memantine tablets. The severity of withdrawal symptoms was measured using the Short Opioid Withdrawal Scale over 3 weeks. Data analysis was performed using SPSS and descriptive and inferential tests.

RESULTS

The results showed that despite memantine's superiority in controlling some withdrawal symptoms such as feeling sick, stomach pain, muscle spasm, and feeling cold, no significant difference was found between the 2 groups. There was also no statistically significant difference between the 2 groups in the total score of symptoms.

CONCLUSIONS

No specific advantage of memantine was found for reducing the symptoms of withdrawal syndrome in the present study. However, this drug was well tolerated without any evidence of serious or significant adverse effects.

Development and validation of a rapid liquid chromatography/tandem mass spectrometry method to quantitate gabapentin and buprenorphine in human serum

RATIONALE

Gabapentin has shown initial promise as an opioid-sparing medication in pain patients as well as a treatment for opioid withdrawal and liquid chriomatography/tandem mass spectrometry (LC/MS/MS) is often used for clinical monitoring. Despite reports of validated tandem mass spectrometric methods for the determination of gabapentin and buprenorphine, mechanisms for the collision-induced fragmentation have not been adequetely described.

METHODS

A rapid analytical method has been developed to determine gabapentinoid, gabapentin, and the partial opioid agonist, buprenorphine, in 20 μL of human serum using LC/MS/MS with a chromatographic run time of 2 min. A simplified sample cleanup procedure using methanol precipitation of serum proteins/lipids followed by evaporation and reconstitution in mobile phase was demonstrated. Gabapentin and buprenorphine were detected following positive ion electrospray ionization using multiple-reaction monitoring. The internal standard approach was used for quantitation with labeled gabapentin-D10 and buprenorphine-D4 serving as internal standards. Using organic reaction principals and stable isotope labels, collision-induced fragmentation mechanisms for both gabapentin and buprenorphine are proposed. The method was validated according to the FDA Guidance for Industry - Bioanalytical Method Validation.

RESULTS

Accuracy was demonstrated by error values ≤15% for buprenorphine and ≤6% for gabapentin. The inter-day precision was ≤4.88% and 15.59% for gabapentin and buprenorphine and the intra-day precision was ≤5.20% and 11.65% for gabapentin and buprenorphine. The lower limit of quantitation corresponded to 10 ng/mL for gabapentin and 1 ng/mL for buprenorphine in serum. Recoveries were 104 ± 2.55% and 85 ± 2.03% for gabapentin and buprenorphine, respectively.

CONCLUSIONS

Concentrations of gabapentin and buprenorphine were determined for five authentic human serum samples to further validate the utility of the method and applicable to therapeutic drug monitoring beyond its use as a drug screening assay. Furthermore, new mechanisms for the collision-induced dissociation of gabapentin and buprenorphine have been proposed.

Detoxification of Neuromodulation Eligible Patients by a Standardized Protocol: A Retrospective Pilot Study

OBJECTIVES

Patients eligible for spinal cord stimulation (SCS) generally experience excruciating pain, requiring more opioid consumption, which is usually an indication for SCS implantation. After final implantation, SCS has the ability to stabilize or decrease opioid usage in half of the patients. In this study, opioids were actively eliminated prior to implantation of any neuromodulation device with a standardized detoxification protocol. This pilot study aims to explore the feasibility, effectiveness, and safety of this opioid detoxification protocol prior to neuromodulation techniques.

MATERIALS AND METHODS

In this retrospective pilot study, 70 patients who were taking opioids and who were eligible for neuromodulation techniques, underwent the detoxification program. A combined in- and out-patient clinic protocol was applied, whereby clonidine was the main component of both parts of the program. A multidisciplinary team with pain physicians and psychologists was responsible for performing this detoxification program. Safety and feasibility were systematically recorded during the hospitalization.

RESULTS

No serious safety issues were reported. At the start of the program, patients reported a mild sedative effect of clonidine. Additionally, most patients presented mild symptoms of opioid withdrawal, which were partially countered by the sedative effect of clonidine. Both patients and the medical staff found this protocol feasible in clinical practice. Concerning the effectiveness, a statistically significant decrease in median morphine milligram equivalents (MMEs) was found with a MME of 175 (Q1-Q3: 118.1-240) at baseline and at the last available follow-up visit the MME was 0 (Q1-Q3: 0-16.88).

CONCLUSIONS

This standardized detoxification program has proven its effectiveness, safety, and feasibility in this single-center experience pilot study in patients eligible for neuromodulation techniques.

Time to re-engage psychiatric drug discovery by strengthening confidence in preclinical psychopharmacology

BACKGROUND

There is urgent need for new medications for psychiatric disorders. Mental illness is expected to become the leading cause of disability worldwide by 2030. Yet, the last two decades have seen the pharmaceutical industry withdraw from psychiatric drug discovery after costly late-stage trial failures in which clinical efficacy predicted pre-clinically has not materialised, leading to a crisis in confidence in preclinical psychopharmacology.

METHODS

Based on a review of the relevant literature, we formulated some principles for improving investment in translational neuroscience aimed at psychiatric drug discovery.

RESULTS

We propose the following 8 principles that could be used, in various combinations, to enhance CNS drug discovery: (1) consider incorporating the NIMH Research Domain Criteria (RDoC) approach; (2) engage the power of translational and systems neuroscience approaches; (3) use disease-relevant experimental perturbations; (4) identify molecular targets via genomic analysis and patient-derived pluripotent stem cells; (5) embrace holistic neuroscience: a partnership with psychoneuroimmunology; (6) use translational measures of neuronal activation; (7) validate the reproducibility of findings by independent collaboration; and (8) learn and reflect. We provide recent examples of promising animal-to-human translation of drug discovery projects and highlight some that present re-purposing opportunities.

CONCLUSIONS

We hope that this review will re-awaken the pharma industry and mental health advocates to the opportunities for improving psychiatric pharmacotherapy and so restore confidence and justify re-investment in the field.

Identifying Opioid Withdrawal Using Wearable Biosensors

Wearable biosensors can be used to monitor opioid use, a problem of dire societal consequence given the current opioid epidemic in the US. Such surveillance can prompt interventions that promote behavioral change. Prior work has focused on the use of wearable biosensor data to detect opioid use. In this work, we present a method that uses machine learning to identify opioid withdrawal using data collected with a wearable biosensor. Our method involves developing a set of machine-learning classifiers, and then evaluating those classifiers using unseen test data. An analysis of the best performing model (based on the Random Forest algorithm) produced a receiver operating characteristic (ROC) area under the curve (AUC) of 0.9997 using completely unseen test data. Further, the model is able to detect withdrawal with just one minute of biosensor data. These results show the viability of using machine learning for opioid withdrawal detection. To our knowledge, the proposed method for identifying opioid withdrawal in OUD patients is the first of its kind.

[Anhedonia, depression, anxiety, and craving in opioid dependent patients stabilized on oral naltrexone or naltrexone implant]

AIM

To assess the relationship between long-term naltrexone treatment and anxiety, depression and craving in opioid dependent individuals.

MATERIAL AND METHODS

Opioid dependent patients (n=306) were enrolled in a three cell (102ss/cell) randomized, double blind, double dummy, placebo-controlled 6-month trial comparing extended release implantable naltrexone with oral naltrexone and placebo (oral and implant). Monthly assessments of affective responses used a Visual Analog Scale for opioid craving, the Beck Depression Inventory, Spielberger Anxiety Inventory, and the Ferguson and Chapman Anhedonia Scales. Between-group outcomes were analyzed using mixed model analysis of variance (Mixed ANOVA) and repeated measures and the post hoc Tukey test.

RESULTS AND CONCLUSION

Anhedonia, depression, anxiety, and craving for opiates were elevated at baseline but gradually reduced to normal within the first 1-2 months for patients who remained in treatment and did not relapse. There were no significant between-group differences prior to treatment dropout as well as between those who relapsed and who continued on naltrexone.

CONCLUSION

These data do not support concerns that naltrexone treatment of opioid dependence precipitates anhedonia, depression, anxiety or craving for opiates.

Time-dependent regional brain distribution of methadone and naltrexone in the treatment of opioid addiction

Opioid addiction is a serious public health concern with severe health and social implications; therefore, extensive therapeutic efforts are required to keep users drug free. The two main pharmacological interventions, in the treatment of addiction, involve management with methadone an mu (μ)-opioid agonist and treatment with naltrexone, μ-opioid, kappa (κ)-opioid and delta (δ)-opioid antagonist. MET and NAL are believed to help individuals to derive maximum benefit from treatment and undergo a full recovery. The aim of this study was to determine the localization and distribution of MET and NAL, over a 24-hour period in rodent brain, in order to investigate the differences in their respective regional brain distributions. This would provide a better understanding of the role of each individual drug in the treatment of addiction, especially NAL, whose efficacy is controversial. Tissue distribution was determined by using mass spectrometric imaging (MSI), in combination with quantification via liquid chromatography tandem mass spectrometry. MSI image analysis showed that MET was highly localized in the striatal and hippocampal regions, including the nucleus caudate, putamen and the upper cortex. NAL was distributed with high intensities in the mesocorticolimbic system including areas of the cortex, caudate putamen and ventral pallidum regions. Our results demonstrate that MET and NAL are highly localized in the brain regions with a high density of μ-receptors, the primary sites of heroin binding. These areas are strongly implicated in the development of addiction and are the major pathways that mediate brain stimulation during reward.

Delay-Dependent Impairments in Memory and Motor Functions After Acute Methadone Overdose in Rats

Methadone is used as a substitution drug for the treatment of opioid dependence and chronic pain. Despite its widespread use and availability, there is a serious concern with respect to the relative safety of methadone. The purpose of this study was to characterize how acute methadone overdose affects the cognitive and motor performance of naïve healthy rats. The methadone overdose was induced by administering an acute toxic dose of methadone (15 mg/kg; ip; the equivalent dose of 80% of LD50) to adolescent rats. Resuscitation using a ventilator pump along with a single dose of naloxone (2 mg/kg; ip) was administered following the occurrence of apnea. The animals which were successfully resuscitated divided randomly into three apnea groups that evaluated either on day 1, 5, or 10 post-resuscitation (M/N-Day 1, M/N-Day 5, and M/N-Day 10 groups) in the Y-maze and novel object memory recognition tasks as well as pole and rotarod tests. The data revealed that a single toxic dose of methadone had an adverse effect on spontaneous behavior. In addition, Recognition memory impairment was observed in the M/N-Day 1, 5, and 10 groups after methadone-induced apnea. Further, descending time in the M/N-Day 5 group increased significantly in comparison with its respective Saline control group. The overall results indicate that acute methadone-overdose-induced apnea produced delay-dependent cognitive and motor impairment. We suggest that methadone poisoning should be considered as a possible cause of delayed neurological disorders, which might be transient, in some types of memory or motor performance in naïve healthy rats.

Extended-release naltrexone (XR-NTX) for opioid use disorder in clinical practice: Vivitrol's Cost and Treatment Outcomes Registry

BACKGROUND AND AIMS

Extended-release naltrexone (XR-NTX), a μ-opioid receptor antagonist for prevention of relapse to opioid dependence, has demonstrated efficacy compared with placebo and comparative effectiveness with buprenorphine-naloxone. We report outcomes for XR-NTX in Vivitrol's Cost and Treatment Outcomes Registry.

DESIGN

Observational, open-label, single-arm, multi-center registry assessing baseline characteristics and clinical and health-related quality-of-life outcomes associated with XR-NTX treatment in clinical practice.

SETTING

32 US treatment centers from 2011 to 2013.

PARTICIPANTS

Patients with opioid dependence who were prescribed XR-NTX treatment and then enrolled into the registry.

MEASUREMENTS

Monthly visits were evaluated for the full population and for patient ubgroups retrospectively, defined by injection number, focusing on the period between baseline and month 6 (1-, 2/3- or 6-XR-NTX).

FINDINGS

Of 403 enrolled patients, 395 were analyzed. Most patients (n = 349) received out-patient care. On average, patients received five injections (median = 3; range = 1-25). The median number of injections administered within 6 months was higher in patients who at baseline were employed (three versus two unemployed, P = 0.02) or had private insurance (five versus two self-payment, P = 0.005; versus two state-funded, P < 0.001). The 1-, 2/3- and 6-XR-NTX groups had 132, 152 and 111 patients, respectively. At baseline, the 6-XR-NTX patients were more likely to meet normal/minimal mental illness criteria and attend school and less likely to report recent drug use. Within 6 months, the 6-XR-NTX group demonstrated improvements in employment, mental health and psychosocial functioning, and decreases in opioid craving, drug use and drug-related behavior.

CONCLUSIONS

Among opioid-dependent people receiving XR-NTX treatment, better mental health, higher education and lower recent drug use at baseline are associated with greater treatment duration; in turn, longer treatment duration is associated with lower relapse rates and improved outcomes generally.

Use of withdrawal management services among people who use illicit drugs in Vancouver, Canada

Background

For many individuals with substance use disorders, the entry point for addiction treatment can be through withdrawal management (e.g. detoxification) services. However, little is known about the factors that predict withdrawal management service use among people who use illicit drugs (PWUD). Using data derived from two prospective cohorts of PWUD, we conducted a longitudinal data analysis of factors associated with use of withdrawal management services.

Methods

Individuals participating in two cohorts of PWUD were prospectively followed between December 2005 and May 2016 in Vancouver, Canada. Bivariate and multivariate generalized estimating equations were used to examine factors associated with use of withdrawal management services.

Results

Out of a total of 2001 participants, 339 (16.9%) individuals reported having been to a withdrawal management centre in the previous 6 months at some point during the study period. In multivariate analyses, male sex (adjusted odds ratio [AOR]: 1.62, 95% Confidence Interval [CI]: 1.17–2.24), homelessness (AOR: 1.86, 95% CI: 1.45–2.38), binge use of any substance (AOR: 1.34, 95% CI: 1.08–1.67), having attended a supervised injection facility (AOR: 1.66, 95% CI: 1.3–2.11), and having accessed other addiction medicine treatment or supports (other than withdrawal management services or opioid agonist therapy; AOR: 3.34, 95% CI: 2.64–4.22) were positively associated with having accessed withdrawal management services, whereas older age (AOR: 0.81, 95% CI: 0.7–0.94) was negatively associated with the outcome.

Conclusions

This study identified specific factors associated with accessing withdrawal management services. Current evidence suggests a need to re-examine the provision of withdrawal management services. Consideration needs to be given to redesigning access to care and bridging to evidence-based addiction treatment, particularly for highly vulnerable subpopulations, identified in this study as females and older people.

Ibogaine Detoxification Transitions Opioid and Cocaine Abusers Between Dependence and Abstinence: Clinical Observations and Treatment Outcomes

Ibogaine may be effective for transitioning opioid and cocaine dependent individuals to sobriety. American and European self-help groups provided public testimonials that ibogaine alleviated drug craving and opioid withdrawal symptoms after only a single dose administration. Preclinical studies in animal models of addiction have provided proof-of-concept evidence in support of these claims. However, the purported therapeutic benefits of ibogaine are based on anecdotal reports from a small series of case reports that used retrospective recruitment procedures. We reviewed clinical results from an open label case series (N = 191) of human volunteers seeking to detoxify from opioids or cocaine with medical monitoring during inpatient treatment. Whole blood was assayed to obtain pharmacokinetic measures to determine the metabolism and clearance of ibogaine. Clinical safety data and adverse events (AEs) were studied in male and female subjects. There were no significant adverse events following administration of ibogaine in a dose range that was shown to be effective for blocking opioid withdrawal symptoms in this study. We used multi-dimensional craving questionnaires during inpatient detoxification to test if ibogaine was effective in diminishing heroin and cocaine cravings. Participants also completed standardized questionnaires about their health and mood before and after ibogaine treatment, and at program discharge. One-month follow-up data were reviewed where available to determine if ibogaine's effects on drug craving would persist outside of an inpatient setting. We report here that ibogaine therapy administered in a safe dose range diminishes opioid withdrawal symptoms and reduces drug cravings. Pharmacological treatments for opioid dependence include detoxification, narcotic antagonists and long-term opioid maintenance therapy. Our results support product development of single oral dose administration of ibogaine for the treatment of opioid withdrawal during medically supervised detoxification to transition drug dependent individuals to abstinence.

OPRM1 influence on and effectiveness of an individualized treatment plan for prescription opioid use disorder patients

Screening for opioid use disorder should be considered in chronic non-cancer pain (CNCP) patients with long-term use of opioids. The aim of our study was to assess the effectiveness of an individualized treatment plan (ITP) for prescription opioid dependence that included screening of pharmacogenetic markers. An observational prospective study was performed using prescription opioid-dependent CNCP outpatients (n = 88). Patients were divided into nonresponders, responders, or high responders according to their response to the ITP. Genotyping of OPRM1 (A118G), OPRD1 (T921C), COMT (G472A), ABCB1 (C3435T), and ARRB2 (C8622T) was performed by real-time PCR. Our ITP achieved a significant reduction of the morphine equivalent daily dose (MEDD) in 64% of responders, including 33% of high responders. Nonopioid medication or buprenorphine use was significantly higher at final versus basal visit. 118-AA OPRM1 patients required significantly lower MEDD at basal and final visits. Our ITP showed effectiveness and security in reducing MEDD in opioid-dependent patients, with good conversion to buprenorphine that was more pronounced in 118-AA OPRM1 patients.

Clinician Referrals for Non-opioid Pain Care Following Discontinuation of Long-term Opioid Therapy Differ Based on Reasons for Discontinuation

BACKGROUND

Little is known about pain care offered to patients discontinued from long-term opioid therapy (LTOT) by their prescriber due to aberrant behaviors versus other reasons.

OBJECTIVE

This study aimed to compare rates of non-opioid analgesic pharmacotherapy initiation and clinician referrals for non-pharmacologic pain treatment, complementary and integrative pain therapies, and specialty mental health and substance use disorder treatment between patients discontinued from opioid therapy due to aberrant behaviors versus other reasons.

DESIGN

The design included retrospective manual electronic health record review and administrative data abstraction.

PARTICIPANTS

Patients were sampled from a national cohort of US Department of Veterans Affairs patients prescribed continuous opioid therapy in 2011 who subsequently discontinued opioid therapy in 2012. The study sample comprised 509 patients discontinued from LTOT by opioid-prescribing clinicians.

MAIN MEASURES

The primary independent variable was reason for discontinuation of LTOT (aberrant behaviors versus other reasons). Pain care dichotomous outcomes included clinician use of an opioid taper; initiating new non-opioid analgesic pharmacotherapy; and referrals for non-pharmacologic pain treatment, complementary and integrative pain therapies, and specialty mental health and substance use disorder treatment.

KEY RESULTS

We observed low rates of opioid taper (15% of patients), initiations of new or modifications of existing non-opioid analgesic pharmacotherapy (45% of patients), and clinician referrals for non-pharmacologic pain treatment (58% of patients) and complementary and integrative therapies (25% of patients). Patients discontinued due to aberrant behaviors, relative to patients discontinued for other reasons, were more likely to receive opioid tapers (adjusted OR = 5.60, 95% CI = 2.10-14.93), receive new non-opioid analgesic medications or dose changes to an existing non-opioid analgesic medications (adjusted OR = 2.61, 95% CI = 1.59-4.29), or be referred for specialty substance use disorder treatment (adjusted OR = 7.39, 95% CI = 3.76-14.53).

CONCLUSIONS

These findings highlight the variability in referral rates for different types of non-opioid pain treatments and challenges accessing specific types of pain care.

Opioid Use Disorder Induces Oxidative Stress and Inflammation: The Attenuating Effect of Methadone Maintenance Treatment

Objective: Frequent use of opioids produces reactive oxygen species, upregulates inflammatory factors, and contributes to opiate dependence. In this study, we examined perturbations of plasma oxidative and inflammatory markers in patients with opioid use disorder in two phases. In the first phase, we compared the oxidative status in patients with opioid use disorders and in healthy controls; and in the second phase, we examined oxidative changes before and after methadone maintenance treatment. Method: To explore whether oxidative changes were associated with opioid use disorder, we compared plasma oxidative and inflammatory markers in patients with opioid use disorder and in smoking and non-smoking healthy participants. All participants completed measures of catalase (CAT), glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), matrix metalloproteinase (MMP-9), and TNF-α at baseline. Baseline measures were compared using Kruskal-Wallis test. In the second phase, to explore oxidative changes during transition from opium use to methadone, blood and urine samples of patients with opioid use disorder were re-evaluated on Days 3, 7, and 14 after methadone therapy. Repeated measures analysis was used to determine the relative contribution of intervention to changes in CAT, GSH, MDA, SOD, MMP-9, and TNF-α level over time. Results: We observed lower SOD and catalase activities, and higher TNF-α and MMP-9 level in patients compared to the two comparison groups. Opioids exacerbated the oxidative imbalance and superimposed the underlying oxidative injury in smoker comparison group. Methadone therapy was associated with lower MMP-9 and TNF-α level, and higher SOD and catalase activities two weeks after therapy; showing an improvement in oxidative profile. Conclusion: This was an investigation indicating an oxidative imbalance before methadone therapy and during early days of transition from opium use to methadone. Being aware of redox status is crucial for determining an appropriate antioxidant therapy in opioid use disorder.

Sustained opioid antagonism modulates striatal sensitivity to baby schema in opioid use disorder

BACKGROUND

Chronic opioid misuse is associated with reduced sensitivity to natural rewards and social motivation deficits that include impaired caregiving. The neurobiological mechanisms underlying these deficits and their response to treatment are not well understood. Baby schema (Kindchenschema) is a set of juvenile physical features, which is perceived as "cute" and triggers motivation for caregiving. Recent studies suggest that the "baby schema effect" is mediated by the brain "reward" network. We studied the impact of opioid antagonist treatment on the baby schema response in patients with opioid use disorder.

METHODS

Forty-seven (24 F) recently detoxified patients with opioid use disorder underwent functional magnetic resonance imaging (fMRI) while viewing infant portraits that were parametrically manipulated for baby schema content and rating them for cuteness, at baseline and during treatment with the injectable extended release opioid antagonist naltrexone (XRNTX). The study was not placebo-controlled.

RESULTS

The behavioral effect of baby schema, indexed by "cuteness" ratings, was present and unaffected by XRNTX. The brain response to baby schema was absent at baseline, but present in the bilateral ventral striatum after two weeks of XRNTX treatment. The decline in self-reported craving for opioids was positively correlated with the brain fMRI response to baby schema in the bilateral ventral striatum.

CONCLUSIONS

Opioid antagonist treatment modulated the brain reward system response to a marker of caregiving motivation in patients with opioid use disorder. Neural response to baby schema may offer a novel probe of social motivation and affiliative behaviors in this population.

Anesthetic implications of recreational drug use

PURPOSE

As the use of recreational drugs increases, the likelihood of an anesthesiologist perioperatively encountering patients using or addicted to these drugs will also increase.

PRINCIPAL FINDINGS

Addicted patients may present for anesthetic care in a variety of circumstances in everyday elective surgeries or in acute or life-saving situations, such as emergency Cesarean delivery or trauma surgery. Therefore, it is important for anesthesiologists to know about the most common illicit drugs being used, their clinical presentation and side effects, and the anesthetic options that are beneficial or detrimental to these patients. The most frequently used illicit substances, apart from alcohol and tobacco, are cannabis, cocaine, heroin, prescription opioids, methamphetamine, and hallucinogens. When planning anesthetic care, it is important for anesthesiologists to understand the effects of these agents, including various drug interactions, to predict tolerance to some anesthetic agents, to recognize drug withdrawal signs and symptoms, and to be prepared to manage all these factors in the perioperative period.

CONCLUSIONS

For optimal patient care through the perioperative period, it is critical to obtain information about patient drug use and other associated treatment in order to construct an appropriate anesthetic plan, including specific considerations during surgery, emergence, and in the postanesthesia care unit.

Nabilone pharmacotherapy for cannabis dependence: A randomized, controlled pilot study

BACKGROUND AND OBJECTIVES

We assessed the safety, tolerability, and preliminary efficacy of nabilone, a cannabinoid agonist, to treat cannabis dependence.

METHODS

Eighteen adults with DSM-IV cannabis dependence were randomized to receive either 2 mg/day of nabilone (n = 10) or placebo (n = 8) for 10 weeks in addition to medication management. Twelve participants, six in each group, completed treatment. The safety and tolerability of nabilone was assessed at each visit. Any side effects from nabilone or the placebo were documented. Cannabis use outcomes were assessed via self-report of days of use and twice-weekly urine cannabinoid tests; secondary outcomes included cannabis craving and anxiety.

RESULTS

We assessed safety and tolerability at each study visit. A total of eight adverse events, all mild or moderate, were reported in two participants in the nabilone group, and six events were reported in four participants in the placebo group during study treatment. A total of eight adverse events were reported in two participants in the nabilone group and six events were reported in four participants in the placebo group during study treatment. All reported adverse events were rated mild-to-moderate. There were no side effects deemed serious enough to be classified as an FDA-defined serious adverse event. In general, participants in both groups reported reduced cannabis use according to self-report over the course of the study, although these reductions were not statistically discernible. Moreover, there was no difference in cannabis use between the nabilone group and the placebo group as measured by self-report.

DISCUSSION AND CONCLUSIONS

Nabilone pharmacotherapy was safe and well-tolerated in participants with cannabis dependence. Future studies might evaluate a higher dose of nabilone to determine its effects on cannabis use outcomes in participants with cannabis dependence.

SCIENTIFIC SIGNIFICANCE

There remains a clear need for additional pharmacotherapy trials for cannabis dependence, and nabilone remains a candidate for such trials. (Am J Addict 2017;26:795-801).

A novel non-opioid protocol for medically supervised opioid withdrawal and transition to antagonist treatment

BACKGROUND

The clinical feasibility of a novel non-opioid and benzodiazepine-free protocol was assessed for the treatment of medically supervised opioid withdrawal and transition to subsequent relapse prevention strategies.

METHODS

A retrospective chart review of DSM-IV diagnosed opioid-dependent patients admitted for inpatient medically supervised withdrawal examined 84 subjects (52 males, 32 females) treated with a 4-day protocol of scheduled tizanidine, hydroxyzine, and gabapentin. Subjects also received ancillary medications as needed, and routine counseling. Primary outcomes were completion of medically supervised withdrawal, and initiation of injectable extended release (ER) naltrexone treatment. Secondary outcomes included the length of hospital stay, Clinical Opiate Withdrawal Scale (COWS) scores, and facilitation to substance use disorder treatment intervention. Ancillary medication use and adverse effects were also assessed.

RESULTS

A total of 79 (94%) of subjects completed medically supervised withdrawal. A total of 27 (32%) subjects chose to pursue transition to ER naltrexone, and 24 of the 27 (89%) successfully received the injection prior to hospital discharge. The protocol subjects had a mean length of hospital stay of 3.6 days, and the mean COWS scores was 3.3, 3.4, 2.8, and 2.4 on Day 1, 2, 3, and 4, respectively. Furthermore, 71 (85%) engaged in an inpatient or outpatient substance use disorder (SUD) treatment program following protocol completion.

CONCLUSION

This retrospective chart review suggests the feasibility of a novel protocol for medically supervised opioid withdrawal and transition to relapse prevention strategies, including injectable ER naltrexone. This withdrawal protocol does not utilize opioid agonists or other controlled substances.‬‬‬‬.

The effect of bundling medication-assisted treatment for opioid addiction with mHealth: study protocol for a randomized clinical trial

BACKGROUND

Opioid dependence has devastating and increasingly widespread consequences and costs, and the most common outcome of treatment is early relapse. People who inject opioids are also at disproportionate risk for contracting the human immunodeficiency virus (HIV) and hepatitis C virus (HCV). This study tests an approach that has been shown to improve recovery rates: medication along with other supportive services (medication-assisted treatment, or MAT) against MAT combined with a smartphone innovation called A-CHESS (MAT + A-CHESS).

METHODS/DESIGN

This unblinded study will randomly assign 440 patients to receive MAT + A-CHESS or MAT alone. Eligible patients will meet criteria for having an opioid use disorder of at least moderate severity and will be taking methadone, injectable naltrexone, or buprenorphine. Patients with A-CHESS will have smartphones for 16 months; all patients will be followed for 24 months. The primary outcome is the difference between patients in the two arms in percentage of days using illicit opioids during the 24-month intervention. Secondary outcomes are differences between patients receiving MAT + A-CHESS versus MAT in other substance use, quality of life, retention in treatment, health service use, and, related to HIV and HCV, screening and testing rates, medication adherence, risk behaviors, and links to care. We will also examine mediators and moderators of the effects of MAT + A-CHESS. We will measure variables at baseline and months 4, 8, 12, 16, 20, and 24. At each point, patients will respond to a 20- to 30-min phone survey; urine screens will be collected at baseline and up to twice a month thereafter. We will use mixed-effects to evaluate the primary and secondary outcomes, with baseline scores functioning as covariates, treatment condition as a between-subject factor, and the outcomes reflecting scores for a given assessment at the six time points. Separate analyses will be conducted for each outcome.

DISCUSSION

A-CHESS has been shown to improve recovery for people with alcohol dependence. It offers an adaptive and extensive menu of services and can attend to patients nearly as constantly as addiction does. This suggests the possibility of increasing both the effectiveness of, and access to, treatment for opioid dependence.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02712034 . Registered on 14 March 2016.

Update on pharmacotherapy for treatment of opioid use disorder

INTRODUCTION

Opioid Use Disorder (OUD) is a significant public health concern, negatively impacting the medical, psychological, and social domains of an individual's life as well as creating substantial burdens for society. Effective treatment interventions are necessary for reduction of OUD and its consequences. Pharmacotherapy represents a central component of management. Areas covered: This review focuses on pharmacologic strategies for OUD treatment, discussing both primary as well as adjunctive therapy modalities. We will discuss both medications used during detoxification to treat withdrawal, as well as those used as maintenance therapy. Detox medications include alpha-2 adrenergic agonists, such as clonidine, as well as the μ-opioid agonist, methadone, and the μ-opioid partial agonist, buprenorphine. Opioid maintenance treatment (OMT) is also discussed, focusing on those medications meant to substitute abused opioids and includes the agonists, methadone and buprenorphine, as well as supervised intravenous heroin, and opioid antagonist, naltrexone. Expert opinion: Medication therapy for treatment of OUD has demonstrated efficacy and is of great clinical benefit. While agonist treatment with methadone or buprenorphine remains the gold standard, there is an important place for use of long-acting antagonist therapy with naltrexone. Continued investigation into treatment paradigms and behavioral platforms which optimize medication therapy is most needed.

Hyperbaric oxygen treatment suppresses withdrawal signs in morphine-dependent mice

Hyperbaric oxygen (HBO2) therapy reportedly reduces opiate withdrawal in human subjects. The purpose of this research was to determine whether HBO2 treatment could suppress physical signs of withdrawal in opiate-dependent mice. Male NIH Swiss mice were injected s.c. with morphine sulfate twice a day for 4 days, the daily dose gradually increasing from 50mg/kg on day 1 to 125mg/kg on day 4. On day 5, withdrawal was precipitated by i.p. injection of 5.0mg/kg naloxone. Mice were observed for physical withdrawal signs, including jumping, forepaw tremor, wet-dog shakes, rearing and defecation for 30min. Sixty min prior to the naloxone injection, different groups of mice received either a 30-min or 60-min HBO2 treatment at 3.5atm absolute. HBO2 treatment significantly reduced naloxone-precipitated jumping, forepaw tremor, wet-dog shakes, rearing and defecation. Based on these experimental findings, we concluded that treatment with HBO2 can suppress physical signs of withdrawal syndrome in morphine-dependent mice.

Anhedonia, depression, anxiety, and craving in opiate dependent patients stabilized on oral naltrexone or an extended release naltrexone implant

BACKGROUND

Naltrexone is a μ-opioid receptor antagonist that blocks opioid effects. Craving, depression, anxiety, and anhedonia are common among opioid dependent individuals and concerns have been raised that naltrexone increases them due to blocking endogenous opioids. Here, we present data that address these concerns.

OBJECTIVE

Assess the relationship between affective responses and naltrexone treatment.

METHODS

Opioid dependent patients (N = 306) were enrolled in a three cell (102ss/cell) randomized, double blind, double dummy, placebo-controlled 6-month trial comparing extended release implantable naltrexone with oral naltrexone and placebo (oral and implant). Monthly assessments of affective responses used a Visual Analog Scale for opioid craving, the Beck Depression Inventory, Spielberger Anxiety Test, and the Ferguson and Chapman Anhedonia Scales. Between-group outcomes were analyzed using mixed model analysis of variance (Mixed ANOVA) and repeated measures and the Tukey test for those who remained and treatment and did not relapse, and between the last measure before dropout with the same measure for those remaining in treatment.

RESULTS

Depression, anxiety, and anhedonia were elevated at baseline but reduced to normal within the first 1-2 months for patients who remained in treatment and did not relapse. Other than a slight increase in two anxiety measures at week two, there were no significant between-group differences prior to treatment dropout.

CONCLUSION

These data do not support concerns that naltrexone treatment of opioid dependence increases craving, depression, anxiety or anhedonia.

Association between trajectories of buprenorphine treatment and emergency department and in-patient utilization

BACKGROUND AND AIMS

Uncertainty about optimal treatment duration for buprenorphine opioid agonist therapy may lead to substantial variation in provider and payer decision-making regarding treatment course. We aimed to identify distinct trajectories of buprenorphine use and examine outcomes associated with these trajectories to guide health system interventions regarding treatment length.

DESIGN

Retrospective cohort study.

SETTING

US Pennsylvania Medicaid.

PATIENTS

A total of 10 945 enrollees aged 18-64 years initiating buprenorphine treatment between 2007 and 2012.

MEASUREMENTS

Group-based trajectory models were used to identify trajectories based on monthly proportion of days covered with buprenorphine in the 12 months post-treatment initiation. We used separate multivariable Cox proportional hazard models to examine associations between trajectories and time to first all-cause hospitalization and emergency department (ED) visit within 12 months after the first-year treatment.

FINDINGS

Six trajectories [Bayesian information criterion (BIC) = -86 246.70] were identified: 24.9% discontinued buprenorphine < 3 months, 18.7% discontinued between 3 and 5 months, 12.4% discontinued between 5 and 8 months, 13.3% discontinued > 8 months, 9.5% refilled intermittently and 21.2% refilled persistently for 12 months. Persistent refill trajectories were associated with an 18% lower risk of all-cause hospitalizations [hazard ratio (HR) = 0.82, 95% confidence interval (CI) = 0.70-0.95] and 14% lower risk of ED visits (HR = 0.86, 95% CI = 0.78-0.95) in the subsequent year, compared with those discontinuing between 3 and 5 months.

CONCLUSIONS

Six distinct buprenorphine treatment trajectories were identified in this population-based low-income Medicaid cohort in Pennsylvania, USA. There appears to be an association between persistent use of buprenorphine for 12 months and lower risk of all-cause hospitalizations/emergency department visits.

Linkage to Primary Care for Persons First Receiving Injectable Naltrexone During Inpatient Opioid Detoxification

INTRODUCTION

Opioid use disorders commonly require ongoing medication-assisted treatment to reduce relapse following discharge from inpatient detoxification programs. Naltrexone, an opioid antagonist, is an increasingly popular treatment option in its once-monthly injectable form (XR-NTX). The aim of this study was to examine the follow-up rates of persons who received an initial injection during inpatient detoxification and scheduled for receipt of a first outpatient injection in the primary care setting.

METHODS

We reviewed the electronic health records of 62 consecutive opioid dependent adults who received an initial injection of XR-NTX during extended inpatient detoxification at Stanley Street Treatment and Resources (SSTAR) in Fall River, Massachusetts, from March 2013 to August 2015, and were referred to the adjacent SSTAR primary care health center for their second injection 1 month later. Demographic information, drug use and opioid treatment history, and aftercare planning were assessed.

RESULTS

Participants averaged 32.4 (±7.8) years of age, 90.3% were non-Latino Caucasian, 35.5% were homeless, 21.3% reported a drug overdose in the last year, and 53.2% had been in detoxification within the last year. Of the 62 participants referred to primary care, 34 (54.8%) followed up to receive their second XR-NTX injection. Twenty of these persons received at least a third XR-NTX injection. No demographic, treatment history, substance use behaviors, or aftercare plan variables were associated with receipt of a second injection (p<.20).

CONCLUSION

Predicting, and therefore improving, XR-NTX continuation during the transition from inpatient detoxification to primary care may be difficult in this population.

Long-term outcomes after randomization to buprenorphine/naloxone versus methadone in a multi-site trial

AIMS

To compare long-term outcomes among participants randomized to buprenorphine or methadone.

DESIGN, SETTING AND PARTICIPANTS

Follow-up was conducted in 2011-14 of 1080 opioid-dependent participants entering seven opioid treatment programs in the United States between 2006 and 2009 and randomized (within each program) to receive open-label buprenorphine/naloxone or methadone for up to 24 weeks; 795 participants completed in-person interviews (~74% follow-up interview rate) covering on average 4.5 years.

MEASUREMENTS

Outcomes were indicated by mortality and opioid use. Covariates included demographics, site, cocaine use and treatment experiences.

FINDINGS

Mortality was not different between the two randomized conditions, with 23 (3.6%) of 630 participants randomized to buprenorphine having died versus 26 (5.8%) of 450 participants randomized to methadone. Opioid use at follow-up was higher among participants randomized to buprenorphine relative to methadone [42.8 versus 31.7% positive opioid urine specimens, P < 0.01, effect size (h) = 0.23 (0.09, 0.38); 5.8 days versus 4.4 days of past 30-day heroin use, P < 0.05, effect size (d) = 0.14 (0.00, 0.28)]. Opioid use during the follow-up period by randomization condition was also significant (F(7,39,600) = 3.16; P < 0.001) due mainly to less treatment participation among participants randomized to buprenorphine than methadone. Less opioid use was associated with both buprenorphine and methadone treatment (relative to no treatment); no difference was found between the two treatments. Individuals who are white or used cocaine at baseline responded better to methadone than to buprenorphine.

CONCLUSIONS

There are few differences in long-term outcomes between buprenorphine and methadone treatment for opioid dependence, and treatment with each medication is associated with a strong reduction in opioid use.

Opioid substitution therapy: Lowering the treatment thresholds

BACKGROUND

Opioid substitution therapy (OST) has been established as the gold standard in treating opioid use disorders. Nevertheless, there is still a debate regarding the qualitative characteristics that define the optimal OST intervention, namely the treatment threshold. The aim of this review is twofold: first, to provide a summary and definition of "treatment thresholds", and second, to outline these thresholds and describe how they related to low and high threshold treatment characteristics and outcomes.

METHOD

We searched the main databases of Medline, PubMed, PsycInfo, EMBASE, CINAHL and the Cochrane Library. Original published research papers, reviews, and meta-analyses, containing the eligible keywords: "opioid substitution", "OST", "low threshold", "high threshold" were searched alone and in combination, up to June, 2015.

RESULTS

Treatment thresholds were defined as barriers a patient may face prior to and during treatment. The variables of these barriers were classified into treatment accessibility barriers and treatment design barriers. There are increasing numbers of studies implementing low threshold designs with an increasing body of evidence suggesting better treatment outcomes compared to high threshold designs.

CONCLUSION

Clinical characteristics of low threshold treatments that were identified to increase the effectiveness of OST intervention include increasing accessibility so as to avoid waiting lists, using personalized treatment options regarding medication choice and dose titration, flexible treatment duration, a treatment design that focuses on maintenance and harm reduction with emphasis on the retention of low adherence patients.

Antagonist Models for Relapse Prevention and Reducing HIV Risk

Naltrexone is an antagonist that binds tightly to μ-opioid receptors and blocks the subjective and analgesic effects of opioids. It does not produce physiologic dependence and precipitates withdrawal if administered to an opioid dependent person, thus starting it must begin with detoxification. It was first available in the mid-1970s as a 50 mg tablet that blocked opioids for 24-36 h if taken daily, or every 2-3 days at higher doses - for example: 100 mg Monday and Wednesday, 150 mg on Friday. From a pharmacological perspective it worked very well and was hoped to be an effective treatment but results were disappointing due to low patient interest and high dropout followed by relapse. Interest in it waned but rose again in the late 1990's when injecting opioid use and the rapid spread of HIV in the Russian Federation converged with an international interest in reducing the spread of HIV. One result was a series of meetings sponsored by the U.S. National Institute on Drug Abuse (NIDA) and Pavlov State Medical University in St. Petersburg, Russian Federation, on ways to reduce the spread of HIV in that country. Addiction treatment was a clear priority and discussions showed that naltrexone could have a role since agonist treatment is against Russian law but naltrexone is approved and the government funds over 25,000 beds for detoxification, which is the first step in starting naltrexone treatment. These meetings were followed by NIDA studies that showed better compliance to oral naltrexone than in prior U.S. studies with the expected reductions in HIV injecting risk for those that stayed in treatment. These events and findings provided a background and identified an infrastructure for the study that led to FDA approval of extended release injectable naltrexone for preventing relapse to opioid dependence. This paper will briefly review findings from these studies and end with comments on the potential role of extended release naltrexone as a meaningful addition to current pharmacotherapies for treating opiod dependence and reducing HIV risk.

Roles of "Wanting" and "Liking" in Motivating Behavior: Gambling, Food, and Drug Addictions

The motivation to seek out and consume rewards has evolutionarily been driven by the urge to fulfill physiological needs. However in a modern society dominated more by plenty than scarcity, we tend to think of motivation as fueled by the search for pleasure. Here, we argue that two separate but interconnected subcortical and unconscious processes direct motivation: "wanting" and "liking." These two psychological and neuronal processes and their related brain structures typically work together, but can become dissociated, particularly in cases of addiction. In drug addiction, for example, repeated consumption of addictive drugs sensitizes the mesolimbic dopamine system, the primary component of the "wanting" system, resulting in excessive "wanting" for drugs and their cues. This sensitizing process is long-lasting and occurs independently of the "liking" system, which typically remains unchanged or may develop a blunted pleasure response to the drug. The result is excessive drug-taking despite minimal pleasure and intense cue-triggered craving that may promote relapse long after detoxification. Here, we describe the roles of "liking" and "wanting" in general motivation and review recent evidence for a dissociation of "liking" and "wanting" in drug addiction, known as the incentive sensitization theory (Robinson and Berridge 1993). We also make the case that sensitization of the "wanting" system and the resulting dissociation of "liking" and "wanting" occurs in both gambling disorder and food addiction.

Predictors of Continued Use of Extended-Released Naltrexone (XR-NTX) for Opioid-Dependence: An Analysis of Heroin and Non-Heroin Opioid Users in Los Angeles County

Extended-release naltrexone (XR-NTX) is associated with an increased number of opioid-free days, improved adherence rates in substance use disorder treatment programs, and reduced cravings and drug-seeking behaviors. There is little evidence on the predictive associations between baseline characteristics of opioid-dependent patients and XR-NTX utilization. Some studies have demonstrated better pharmacotherapy adherence and/or retention rates among non-heroin opioid users compared to heroin users. This study examines predictive associations between characteristics of patients and XR-NTX utilization, as well as participants' urge to use opiates. Our findings suggest that XR-NTX may contribute to decreases in urges to use among both heroin and non-heroin opioid users. Non-heroin opioid users and heroin users were retained in XR-NTX treatment for comparable periods of time. However, those who identified as homeless, injected opioids (regardless of opioid-type), or were diagnosed with a mental illness were less likely to be retained in treatment with XR-NTX.

[A double-blind randomized placebo-controlled study of the efficacy of the combined treatment with naltrexone and guanfacine for relapse prevention in opiate dependence]

OBJECTIVE

Authors studied the effect of α-2-adrenoreceptor agonist guanfacine on replace prevention in opiate addicts.

MATERIAL AND METHODS

Three hundred and one recently detoxified opiate addicts were randomized under the double-blind double-dummy conditions into one of four treatment groups: naltrexone 50 mg/day+guanfacine 1 mg/day (N+G), naltrexone+guanfacine placebo (N+GP), naltrexone placebo+guanfacine (NP+G), and double placebo (NP+GP). The primary outcome was retention in treatment. The secondary outcomes were perceived stress (Perceived Stress Scale) and craving.

RESULTS

At the end of six months, 20 (26.7%) patients in the N+G group and 15 (19.7%) (p=0.26 to N+G) in N+GP group were retained in treatment compared to 5 (6.7%) in the NP+G group (p=0.002 to N+G group and p=0.017 to N+GP group) and 8 (10.7%) in the double placebo group (p=0.013 to N+G group). There is no significant difference in retention between the N+G group and N+GP group at the end of treatment.

CONCLUSION

Guanfacine had significant craving and stress reducing effect. Naltrexone was more effective than placebo for relapse prevention in opioid dependent patients. The efficacy of the combination of naltrexone and guanfacine was comparable to naltrexone alone. Guanfacine moderately reduced both stress and craving.