Methadone overdose deaths rise with increased prescribing for pain

Effects of CB1 receptor negative allosteric modulator Org27569 on oxycodone withdrawal symptoms in mice

RATIONALE/OBJECTIVES

Targeting cannabinoid receptor type 1 (CB1R) has shown promise for treating opioid withdrawal symptoms. This study aimed to investigate the efficacy of a specific CB1R negative allosteric modulator (NAM), Org27569, in reducing both naloxone-precipitated and protracted withdrawal symptoms in oxycodone-dependent mice.

METHODS

Mice received escalating doses of oxycodone (9-33 mg/kg IP) or saline twice daily for 9 days, followed by a final dose of oxycodone (33 mg/kg) or saline in the morning of day 9. In one cohort, the impact of Org27569 (3, 10, and 30 mg/kg) on naloxone (10 mg/kg IP) precipitated withdrawal symptoms was assessed. In another cohort, Org27569 (3 mg/kg) effects on the acquisition of conditioned place aversion to naloxone (0.6 mg/kg) precipitated opioid withdrawal, on behaviour following a 7-9-day abstinence period, and on naloxone (0.6 mg/kg) precipitated withdrawal-induced escape behaviour in a novel assay were assessed.

RESULTS

Although Org27569 decreased opioid withdrawal-induced jumping at doses of 10 and 30 mg/kg, these effects were confounded by reduced locomotion. At all doses tested, Org27569 had a modest inhibitory effect on gastrointestinal motility. At the lower dose of 3 mg/kg, which was not confounded by locomotor effects, Org27569 did not impact naloxone-precipitated withdrawal-induced jumping, acquisition of oxycodone withdrawal-induced conditioned place aversion, or naloxone-precipitated withdrawal-induced escape behaviour in a novel assay. A clear protracted opioid withdrawal phenotype was not observed in assays of anxiety-like or social behaviour.

CONCLUSIONS

Org27569 effects on negative affective-like symptoms were confounded by locomotor effects and effects on gastrointestinal motility were not opioid withdrawal specific. Further studies are needed in a model that produces a more pronounced protracted withdrawal syndrome.

Cannabidiol Reduced the Severity of Gastrointestinal Symptoms of Opioid Withdrawal in Male and Female Mice

Introduction: Opioid withdrawal is a powerful driver of drug-seeking behavior as relief from this aversive state through drug-taking is a strong negative reinforcer. There are currently limited treatment options available for opioid withdrawal and cannabidiol (CBD) has been identified as a potential novel therapeutic. This study explored the efficacy and dose dependency of CBD for reducing the severity of naloxone-precipitated and spontaneous oxycodone withdrawal (PW and SW, respectively) in male and female mice. Methods: Mice were administered saline or escalating doses of oxycodone, whereby 9, 17.8, 23.7, and 33 mg/kg oxycodone IP was administered twice daily on days 1-2, 3-4, 5-6, and 7-8, respectively. On the 9th day, a single 33 mg/kg dose of oxycodone (or saline) was administered. To precipitate withdrawal, on day 9, mice in the withdrawal conditions were administered an IP injection of 10 mg/kg naloxone 2 h after the final oxycodone injection and immediately before withdrawal testing. To elicit SW, a separate group of mice underwent withdrawal testing 24 h after their final oxycodone injection. Mice were treated with an IP injection of 0, 10, 30 or 100 mg/kg of CBD 60 min before testing. Withdrawal symptoms examined included gastrointestinal symptoms (fecal boli, diarrhea, and body weight loss), somatic symptoms (paw tremors), and negative affect (jumping). Results: A robust PW syndrome was observed in both male and female mice, whereas only male mice displayed an SW syndrome. CBD dose dependently reduced gastrointestinal symptoms during both PW and SW in male mice and during PW in female mice. CBD had no effect on PW- or SW-induced jumping in male mice. However, in female mice, the PW-induced increase in jumps was less pronounced in CBD-treated mice. The highest dose of CBD inhibited paw tremors during PW, but not SW, in male mice. Neither PW- nor SW-induced paw tremors were observed in female mice. Conclusions: The magnitude of effects on the gastrointestinal symptoms, their consistency across PW and SW, and both sexes, alongside the availability of CBD for clinical use, suggest further exploration of the potential for CBD to treat these symptoms could be justified.

Methadone Prescribing for Pain Management in Pennsylvania per the Prescription Drug Monitoring Program, 2016–2020

Introduction

Methadone is a schedule II opioid traditionally used to treat opioid use disorder (OUD) and chronic pain. However, following the identification of its contribution to opioid overdose deaths, methadone has become less commonly used for chronic pain indications. In Pennsylvania (PA), prescribers are required to report methadone prescriptions written for pain indications to the prescription drug monitoring program (PDMP), which is an electronic database that enhances the tracking and reporting of prescription data. The primary objective of our study was to describe the geographic methadone prescribing trends recorded by the PA PDMP in order to report methadone’s current use for only pain indications. 

Methods

State- and county-level methadone prescription data summaries recorded by the PA PDMP for each calendar quarter from August 2016 through March 2020 were collected from the PA Department of Health. The metric reported per quarter consisted of the total number of methadone prescriptions dispensed for pain indications unrelated to OUD.

Results

A total of 341,949 methadone prescriptions were dispensed in PA from the third quarter (Q3) of 2016 to the first quarter (Q1) of 2020 (range = 1106) with an overall 38.7% decrease in methadone prescriptions and a change in the rate of 85.97 per 100,000 population. The counties with the five highest prescription totals were Philadelphia, Allegheny, Bucks, Montgomery, and York (range = 46,969), and the counties with the five highest rates per 100,000 were Montour, Green, Columbia, Northumberland, and Forest (range = 964).

Conclusions

Methadone prescribing for pain management unrelated to OUD has decreased in PA from 2016 to 2020 per the PA PDMP. However, it is still prescribed in appreciable amounts for pain management. Further studies are required to understand the prescribing rationale and potential areas for harm reduction interventions.

Expanding access to methadone treatment in Ohio through federally qualified health centers and a chain pharmacy: A geospatial modeling analysis

BACKGROUND

In the United States, methadone provision for opioid use disorder (OUD) occurs at opioid treatment programs (OTPs). Ohio recently enacted a policy to expand methadone administration to Federally Qualified Health Centers (FQHC). We compared how the provision of methadone at current OTPs or the proposed expansion to FQHCs and pharmacies meets the urban and rural need for OUD treatment.

METHODS

Cross-sectional geospatial analysis of zip codes within Ohio with at least one 2017 opioid overdose death stratified by Rural-Urban Commuting Area codes. Our primary outcome was the proportion of need by zip code (using opioid overdose deaths as a proxy for need) within a 15- or 30- minute drive time of an OTP.

RESULTS

Among 581 zip codes, sixty four percent of treatment need was within a 15-minute drive time and 81 %, within a 30-minute drive time. The proportion of need within a 15-minute drive decreased with increasing rural classification (urban 78 %, suburban 20 %, large rural 9%, and small rural 1%;p<.001). The portion of need within a 15-minute drive time increased with the addition of FQHCs (96 %) and the addition of chain pharmacies (99 %) relative to OTPs alone among all zip codes and for all urban-rural strata (p<.001).

CONCLUSION

Over one-third of OUD treatment need was not covered by existing OTPs and coverage decreased with rural classification of zip codes. Most of the gap between supply and need could be mitigated with FQHC methadone provision, which would expand both urban and rural access.

Population Pharmacokinetics of Methadone after Oral Administration in Japanese Patients with Cancer-Related Pain

Methadone tablets were approved for use in Japan in March 2013. The metabolism of methadone is complex and executed mainly by the cytochromes, CYP3A4 and CYP2B6. The aim of this study was to evaluate the pharmacokinetics of methadone upon oral administration in Japanese patients who experienced cancer-related pain. The concentration of the drug in blood samples was measured in 25 patients undergoing methadone therapy, and the factors leading to variations were investigated. A population pharmacokinetic analysis was evaluated using the Phoenix® NLME^TM software. Based on this, the ALBI (albumin-bilirubin) score was identified as a significant factor that could be used to assess variations in the serum concentration of methadone, which was then incorporated into the following final model formula: clearance (L/h) = 5.38 × (ALBI score/-2.139)^1.88. The results of these pharmacokinetic parameters suggested that, in clinical use, the dose of methadone should be reduced if liver function declined in patients with cancer-related pain.

An ethical analysis of medication treatment for opioid use disorder (MOUD) for persons who are incarcerated

Opioid use disorder (OUD) is highly prevalent among persons who are incarcerated. Medication treatment for opioid use disorder (MOUD), methadone, buprenorphine, and naltrexone, is widely used to treat OUD in the community. Despite MOUD's well-documented effectiveness in improving health and social outcomes, its use in American jails and prisons is limited.Several factors are used to justify limited access to MOUD in jails and prisons including: "uncertainty" of MOUD's effectiveness during incarceration, security concerns, risk of overdose from MOUD, lack of resources and institutional infrastructure, and the inability of people with OUD to provide informed consent. Stigma regarding MOUD also likely plays a role. While these factors are relevant to the creation and implementation of addiction treatment policies in incarcerated settings, their ethicality remains underexplored.Using ethical principles of beneficence/non-maleficence, justice, and autonomy, in addition to public health ethics, we evaluate the ethicality of the above list of factors. There is a two-fold ethical imperative to provide MOUD in jails and prisons. Firstly, persons who are incarcerated have the right to evidence-based medical care for OUD. Secondly, because jails and prisons are government institutions, they have an obligation to provide that evidence-based treatment. Additionally, jails and prisons must address the systematic barriers that prevent them from fulfilling that responsibility. According to widely accepted ethical principles, strong evidence supporting the health benefits of MOUD cannot be subordinated to stigma or inaccurate assessments of security, cost, and feasibility. We conclude that making MOUD inaccessible in jails and prisons is ethically impermissible.

Opioid Overdose History, Risk Behaviors, and Knowledge in Patients Taking Prescribed Opioids for Chronic Pain

Objective

More than 100 million adults in the United States experience chronic pain, and prescription opioids are the third most widely prescribed class of medications. Current opioid overdose prevention efforts almost exclusively target illicit opioid users, and little is known about the experience of overdose among patients being treated for chronic pain (CP) with a prescription opioid.

Methods

Patients experiencing CP for three or more months and receiving a prescription opioid for pain management (N = 502) completed a self-report survey that asked questions about opioid overdose history, past 30-day risk factors, and knowledge of opioid overdose, overdose risk, and naloxone.

Results

Approximately one in five CP participants reported experiencing a lifetime overdose. CP participants reported engaging in several behaviors associated with overdose risk and were unlikely to have been trained to administer naloxone. Fewer than 50% of participants answered any knowledge item correctly. The likelihood of having experienced an overdose increased as the scores on the SOAPP-R and DSM-5 opioid use disorder checklist increased, and a SOAPP-R score of 7 or higher or meeting DSM-5 mild opioid use disorder criteria were significantly associated with reporting a lifetime overdose (85% and 84% of participants who experienced an overdose, respectively).

Conclusions

Opioid overdose occurs at a high rate among CP participants, and this group is relatively uninformed about risk factors for overdose. Established SOAPP-R and DSM thresholds provide an opportunity to identify participants at elevated risk for having experienced an opioid overdose. These data support development of additional concentrated efforts to prevent overdose among chronic pain patients.

The source and diversion of pharmaceutical drugs for non-medical use: A systematic review and meta-analysis

BACKGROUND

The non-medical use (NMU) of pharmaceutical drugs is an increasing public health concern. This systematic review consolidates current knowledge about how pharmaceutical drugs are obtained for NMU and the processes and people involved in diversion.

METHODS

Peer-reviewed and grey literature databases were searched for empirical studies published between 1996 and 2017 that examined the source or diversion of pharmaceutical opioids, sedatives or stimulants for NMU in countries with reported misuse problems. Pooled prevalence meta-analyses using random effects models were used to estimate the prevalence of medical and non-medical sourcing reported by end-users, and gifting, selling and trading by various populations.

RESULTS

This review synthesizes the findings of 54 cross-sectional studies via meta-analyses, with a remaining 95 studies examined through narrative review. Pharmaceutical drugs are primarily sourced for NMU from friends and family (57%, 95% CI 53%-62%, I² = 98.5, n = 30) and despite perceptions of healthcare professionals to the contrary, illegitimate practices such as doctor shopping are uncommon (7%, 95% CI 6%-10%, I² = 97.4, n = 29). Those at risk of diversion include patients displaying aberrant medication behaviors, people with substance use issues and students in fraternity/sorority environments. Sourcing via dealers is also common (32%, 95% CI 23%-41%, I² = 99.8, n = 25) and particularly so among people who use illicit drugs (47%, 95% CI 35%-60%, I² = 99.1, n = 15). There is little to no organized criminal involvement in the pharmaceutical black market.

CONCLUSION

Pharmaceutical drugs for NMU are primarily sourced by end-users through social networks. Future research should examine how dealers source pharmaceutical drugs.

Prevalence of chronic pain with neuropathic characteristics: a randomized telephone survey among medical center patients in Kuwait

Background

Chronic pain with neuropathic characteristics is considered to be an international health problem. However, surveys on the actual incidence of neuropathic pain have not been conducted in many Middle East countries, including Kuwait. The aim of this study was to examine the incidence of pain and medical comorbidities among a random sample of patients treated at a large medical center in Kuwait.

Methods

A list of 1,000 patients was created from the hospital medical record system, and a telephone survey was conducted on 759 patients who responded to the phone call, of which 67.2% (N=510) participated. Those who stated that they had pain every day for the past 3 months were invited to answer additional questions about their pain.

Results

Fifty-six percentage of those surveyed (N=283) reported experiencing chronic pain. Total average age was 49.2 years (SD=14.5), 45.5% were female, and 70.5% were Kuwaiti nationals. Most (74.3%) reported having diabetes and one-third (32.2%) showed evidence of neuropathic pain characteristics (mean DN4=2.8, SD=1.7). Other comorbid medical conditions were prevalent (48.4% hypertension, 30.4% arthritis, 22.6% heart disease, and 20.4% asthma) with an average of 2.3 (SD=1.3) medical problems per person. Those with pain tended to be older, female, unemployed, and overweight (p<0.01). The pain was mostly located in the lower extremities and those with neuropathic pain tended to report a higher intensity of pain and a higher frequency of seeking treatment for their pain in a clinic or hospital (p<0.05). Most relied on over-the-counter medications for their pain (38.1%). Very few were taking prescription medication for their pain.

Conclusion

This survey suggests that chronic pain is more prevalent in a medical population in Kuwait than previously anticipated. Health care services and behavioral interventions to improve lifestyle changes in Kuwait and other Arab countries are needed to positively impact pain and reduce other comorbidities.

Factors Associated with Prescription of Opioids and Co-prescription of Sedating Medications in Individuals with HIV

Opioids are often prescribed for chronic pain, and opioid risks such as overdose and death are heightened when opioids are co-prescribed with other sedating medications. We investigated factors associated with chronic opioid prescription, alone and in combination with benzodiazepines and muscle relaxants, in a clinical cohort of individuals with HIV. We used multivariable logistic regression models to determine participant clinical and demographic characteristics that are associated with chronic prescription of opioids or chronic co-prescription of opioids with sedating medications. Among 1474 participants, chronic prescription of opioids occurred in 253 individuals (17.2 %), and chronic co-prescription occurred in 90 individuals (6.1 %). Age >50, public insurance as compared to private insurance, and symptoms of depression and anxiety were significantly associated with chronic opioid prescription and chronic co-prescription. Our findings raise concern that opioid prescription and co-prescription of sedating medications occurs disproportionately in patients for whom use is riskier.

Methadone Recycling Sustains Drug Reservoir in Tissue

We hypothesize that there is a tissue store of methadone content in humans that is not directly accessible, but is quantifiable. Further, we hypothesize the mechanism by which methadone content is sustained in tissue stores involves methadone uptake, storage, and release from tissue depots in the body (recycling). Accordingly, we hypothesize that such tissue stores, in part, determine plasma methadone levels. We studied a random sample of six opioid-naïve healthy subjects. We performed a clinical trial simulation in silico using pharmacokinetic modeling. We found a large tissue store of methadone content whose size was much larger than methadone's size in plasma in response to a single oral dose of methadone 10 mg. The tissue store measured 13-17 mg. This finding could only be explained by the contemporaneous storage of methadone in tissue with dose recycling. We found that methadone recycles 2-5 times through an inaccessible extravascular compartment (IAC), from an accessible plasma-containing compartment (AC), before exiting irreversibly. We estimate the rate of accumulation (or storage) of methadone in tissue was 0.029-7.29 mg/h. We predict 39 ± 13% to 83 ± 6% of methadone's tissue stores "spillover" into the circulation. Our results indicate that there exists a large quantifiable tissue store of methadone in humans. Our results support the notion that methadone in humans undergoes tissue uptake, storage, release into the circulation, reuptake from the circulation, and re-release into the circulation, and that spillover of methadone from tissue stores, in part, maintain plasma methadone levels in humans.

Prediction of pain outcomes in a randomized controlled trial of dose-response of spinal manipulation for the care of chronic low back pain

Background

No previous studies have created and validated prediction models for outcomes in patients receiving spinal manipulation for care of chronic low back pain (cLBP). We therefore conducted a secondary analysis alongside a dose-response, randomized controlled trial of spinal manipulation.

Methods

We investigated dose, pain and disability, sociodemographics, general health, psychosocial measures, and objective exam findings as potential predictors of pain outcomes utilizing 400 participants from a randomized controlled trial. Participants received 18 sessions of treatment over 6-weeks and were followed for a year. Spinal manipulation was performed by a chiropractor at 0, 6, 12, or 18 visits (dose), with a light-massage control at all remaining visits. Pain intensity was evaluated with the modified von Korff pain scale (0–100). Predictor variables evaluated came from several domains: condition-specific pain and disability, sociodemographics, general health status, psychosocial, and objective physical measures. Three-quarters of cases (training-set) were used to develop 4 longitudinal models with forward selection to predict individual “responders” (≥50 % improvement from baseline) and future pain intensity using either pretreatment characteristics or post-treatment variables collected shortly after completion of care. The internal validity of the predictor models were then evaluated on the remaining 25 % of cases (test-set) using area under the receiver operating curve (AUC), R², and root mean squared error (RMSE).

Results

The pretreatment responder model performed no better than chance in identifying participants who became responders (AUC = 0.479). Similarly, the pretreatment pain intensity model predicted future pain intensity poorly with low proportion of variance explained (R² = .065). The post-treatment predictor models performed better with AUC = 0.665 for the responder model and R² = 0.261 for the future pain model. Post-treatment pain alone actually predicted future pain better than the full post-treatment predictor model (R² = 0.350). The prediction errors (RMSE) were large (19.4 and 17.5 for the pre- and post-treatment predictor models, respectively).

Conclusions

Internal validation of prediction models showed that participant characteristics preceding the start of care were poor predictors of at least 50 % improvement and the individual’s future pain intensity. Pain collected shortly after completion of 6 weeks of study intervention predicted future pain the best.

Chronic Pain, Comorbid Medical Conditions, and Associated Risk Factors in Kuwait: Gender and Nationality Differences

OBJECTIVE

Chronic pain is an international health problem that imposes enormous costs on societies around the world. There is good reason to suspect that chronic pain is a serious health issue in Kuwait and is associated with comorbid medical conditions like diabetes. The aim of this study is to examine the report of pain and incidence of medical comorbidities among a large convenience sample of patients treated at a private rehabilitation center in Kuwait and to examine differences in patient groups based on age, gender, and Kuwaiti nationality.

METHODS

This study examined intake data from 2,103 patients treated at a rehabilitation center in Kuwait. Most of the subjects were female (55.4%) and averaged 43.3 years of age (±14.5, range 18-88). Sixty nine percent were Kuwaiti citizens and 57.9% were employed.

RESULTS

Marked differences in pain and health-related conditions were found between Kuwaiti nationals and non-Kuwaitis, with significantly increased incidences of hypertension, osteoarthritis, diabetes, asthma, osteoporosis, and cardiac and respiratory problems among the Kuwaitis (P < 0.001). Notable gender differences were also identified with women reporting more intense, widespread pain, and reporting more comorbid medical problems compared with men (P < 0.001).

CONCLUSIONS

This extensive survey study that found female Kuwaitis to have a higher incidence of pain and medical comorbidities than males and non-Kuwaitis highlights the role of cultural factors in contributing to pain and comorbid medical conditions. This information is critical in organizing resources to implement adequate healthcare services and behavioral interventions in Kuwait and other Arab countries to improve pain and health-related conditions.

Out-of-hospital mortality among patients receiving methadone for noncancer pain

IMPORTANCE

Growing methadone use in pain management has raised concerns regarding its safety relative to other long-acting opioids. Methadone hydrochloride may increase the risk for lethal respiratory depression related to accidental overdose and life-threatening ventricular arrhythmias.

OBJECTIVE

To compare the risk of out-of-hospital death in patients receiving methadone for noncancer pain with that in comparable patients receiving sustained-release (SR) morphine sulfate.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted using Tennessee Medicaid records from 1997 through 2009. The cohort included patients receiving morphine SR or methadone who were aged 30 to 74 years, did not have cancer or another life-threatening illness, and were not in a hospital or nursing home. At cohort entry, 32 742 and 6014 patients had filled a prescription for morphine SR or methadone, respectively. The patients' median age was 48 years, 57.9% were female, and comparable proportions had received cardiovascular, psychotropic, and other musculoskeletal medications. Nearly 90% of the patients received the opioid for back pain or other musculoskeletal pain. The median doses prescribed for morphine SR and methadone were 90 mg/d and 40 mg/d, respectively.

MAIN OUTCOMES AND MEASURES

The primary study end point was out-of-hospital mortality, given that opioid-related deaths typically occur outside the hospital.

RESULTS

There were 477 deaths during 28 699 person-years of follow-up (ie, 166 deaths per 10 000 person-years). After control for study covariates, patients receiving methadone had a 46% increased risk of death during the follow-up period, with an adjusted hazard ratio (HR) of 1.46 (95% CI, 1.17-1.83; P < .001), resulting in 72 (95% CI, 27-130) excess deaths per 10 000 person-years of follow-up. Methadone doses of 20 mg/d or less, the lowest dose quartile, were associated with an increased risk of death (HR, 1.59; 95% CI, 1.01-2.51, P = .046) relative to a comparable dose of morphine SR (<60 mg/d).

CONCLUSIONS AND RELEVANCE

The increased risk of death observed for patients receiving methadone in this retrospective cohort study, even for low doses, supports recommendations that it should not be a drug of first choice for noncancer pain.

The QTc effect of low-dose methadone for chronic pain: a prospective pilot study

OBJECTIVE

Methadone is associated with QT prolongation and serious cardiac complications, but this has been primarily demonstrated in opioid dependent patients receiving moderate to high doses. This study investigates the effect of low-dose methadone on the QTc interval in a chronic pain population.

DESIGN AND SUBJECTS

We conducted a prospective cohort study in a chronic pain clinic including 82 patients receiving methadone and 102 patients receiving non-methadone opioid therapy.

METHODS

We analyzed automated QTc calculations from 12-lead electrocardiograms at baseline and during the subsequent 6 months. The primary outcome of interest was the incidence of QTc greater than 470 milliseconds or an increase from baseline of greater than 60 milliseconds.

RESULTS

The methadone group did not manifest an overall higher frequency of QTc > 470 milliseconds (6% for the methadone group vs 5% for controls, P = 0.722) or an increase in the QTc of > 60 milliseconds (4% for the methadone group vs 4% for controls, P = 0.94). In the first month after initiating methadone, patients demonstrated an increase in QTc compared to controls (5% for the methadone group vs 0% for the controls, P = 0.073) but the difference disappeared in the third and sixth months.

CONCLUSION

Data from our chronic pain clinic support a potential association of QTc prolongation during the initiation of methadone, but this effect is small and short lived. We believe larger scale studies to further characterize the safety profile of low-dose methadone are warranted.

Diversion of prescribed opioids by people living with chronic pain: results from an Australian community sample

INTRODUCTION AND AIMS

There has been an increase in prescription of opioids for chronic non-cancer pain, and concern exists over possible diversion of prescription opioids to the illicit marketplace. Recent media coverage suggests that elderly patients sell their prescribed opioids for additional income. This study investigated the extent to which an Australian community sample of chronic pain patients prescribed opioids reported supplying their prescribed opioids to others.

DESIGN AND METHODS

Participants living with chronic non-cancer pain and prescribed opioids for their pain (n=952) were recruited across Australia via advertisements at pharmacies. A telephone interview included questions about their pain condition and opioid medication.

RESULTS

Participants had been living with pain for a mean of 14.2 years; most common conditions included chronic back/neck problems and arthritis/rheumatism. Around half (43%) were currently prescribed one opioid, and 55% had been prescribed 2-5 opioids; the most common was oxycodone. Forty-two participants (4%) reported ever supplying prescribed opioids to another person; one participant reported receiving payment. Participants who supplied opioids to others were younger (odds ratio 0.97, 95% confidence interval 0.95-0.99) and engaged in a greater number of aberrant behaviours relating to their opioid medication (odds ratio 1.77, 95% confidence interval 1.45-2.17), including tampering with doses, taking opioids by alternative routes, seeing doctors to obtain extra opioids and refilling prescriptions early.

DISCUSSION AND CONCLUSION

Few people with chronic non-cancer pain divert their opioids to others. Media reports of elderly patients selling their opioids to supplement their income may be reflective of exceptional cases. Future studies may investigate the extent to which other patient groups divert prescription opioids to the illicit marketplace.

The safety of prescribing opioids in pediatrics

INTRODUCTION

Pain management has become a widely discussed topic throughout all medical subspecialties. Although pediatric pain management has evolved significantly in its recent history, there is continued interest in the adequacy of pain treatment, both in the acute inpatient setting as well as the postoperative and chronic pain management setting. Although health care providers are becoming more aggressive concerning prompt and effective treatment of acute and chronic pain, safety data and adverse effects of narcotic analgesics may be overlooked.

AREAS COVERED

The authors review the current paradigm of acute pain management with an emphasis on oral narcotic medications, and the safety data available concerning prescribing these medications.

EXPERT OPINION

Further, the authors present their opinions concerning current and future practices regarding the prescribing practice of opiate analgesics, as well as a step-wise approach for acute oral pain management.

Metabolic and toxicological considerations of the opioid replacement therapy and analgesic drugs: methadone and buprenorphine

INTRODUCTION

Methadone and buprenorphine are maintenance replacement therapies for opioid dependence; they are also used for pain management. Methadone and buprenorphine (to a lesser extent) have seen sharp increases in mortality associated with their use. They have distinct routes of metabolism (mostly cytochrome P450 dependent), and distinct pharmacologic activity of metabolites. As such, metabolism may play a role in differences in their toxicity.

AREAS COVERED

This article reviews peer-reviewed literature obtained from PubMed searches and literature referenced within. The review considers first an overview of drug use and mortality over the past decade. It then provides extensive detail on the in vitro and in vivo human metabolism of methadone and buprenorphine. Using both human and experimental animal studies it then presents the pharmacodynamic activity of parent drug and metabolites at the mu-opioid receptor, as P-glycoprotein substrates and plasma/brain concentration ratios, and activity at the hERG K(+) channel. Lessons learned from drug interaction studies in humans are then examined in an attempt to bring together the combined information.

EXPERT OPINION

The use and misuse of these drugs contributes to the epidemic in opioid-associated mortalities. A better understanding of metabolism-, transport- and co-medication-induced changes will contribute to their safer use.