Methadone- and buprenorphine-related ambulance attendances: A population-based indicator of adverse events

Factors Associated With Relapse in Individuals With Opioid Use Disorder Receiving Suboxone in Rural Areas

BACKGROUND

Opioid use disorder (OUD), including opioid misuse, abuse, and overdose, has evolved into a national crisis with a lasting effect on society, individuals, and health care systems. Although an office-based treatment of Suboxone combined with counseling is a viable option for individuals with OUD and has been shown to reduce utilization of medical services, the relapse rate among those individuals remains high. There is a need to investigate factors associated with relapse to tailor treatment programs in an effort to prevent relapse. This study aimed to examine factors associated with relapse in individuals with OUD receiving Suboxone.

METHODS

A convenience sample was recruited from an outpatient Suboxone facility located in a rural county of New York. Measures included urine drug testing obtained through the medical record, patterns of time to relapse as measured by the Time to Relapse Questionnaire, pain intensity, and a demographic questionnaire. Descriptive statistics, independent t test, and chi-square statistics were utilized for data analysis.

RESULTS

Forty-six patients participated in the study. Length of time in a Suboxone program, scores in sudden and long delay relapse, and the type of treatment program were statistically associated with relapse.

CONCLUSION

This study provided insight regarding factors contributing to relapse and different time-to-relapse styles that could be incorporated into clinical practice to help prevent relapse.

Characteristics of oxycodone-related ambulance attendances: analysis of temporal trends and the effect of reformulation in Victoria, Australia from 2013 to 2018

BACKGROUND AND AIMS

In Australia, oxycodone has been associated with increasing rates of harm over time, despite reduced use, reformulation to a tamper-resistant form and in contrast to most prescription opioids. We explored characteristics of oxycodone-related ambulance attendances to understand whether presentation characteristics could explain increasing oxycodone harm.

DESIGN

Retrospective study of coded ambulance patient care records related to extramedical oxycodone use, January 2013 to September 2018.

SETTING

Victoria, Australia.

CASES

A total of 2788 oxycodone-related ambulance attendances.

MEASUREMENTS

Primary outcomes were temporal changes in characteristics of oxycodone presentations over time (from 2013 to 2018) and following reformulation. Covariates include demographic characteristics, presentation severity, mental health, substance use and poisoning intent.

FINDINGS

Average age was 41.3 (± 16.4) years with females comprising 56.4% of attendances (n = 2788). The proportion of females in oxycodone-related attendances increased over time [an average increase in the odds ratios of 5% per year (OR) = 1.05, 95% confidence interval (CI) = 1.01-1.10]. Other temporal trends included a reduced likelihood of naloxone administration (OR = 0.92, 95% CI = 0.85-1.00), heroin involvement (OR = 0.81, 95% CI = 0.66-0.99), comorbid mental health symptoms (OR = 0.87, 95% CI = 0.82-0.92) and unknown intent poisoning (OR = 0.91, 95% CI = 0.85-0.96); and a greater risk of alcohol involvement (OR = 1.06, 95% CI = 1.01-1.11), non-opioid extramedical pharmaceutical use (OR = 1.05, 95% CI = 1.01-1.10), comorbid suicidal thoughts or behaviours (OR = 1.10, 95% CI = 1.05-1.15) and past history of psychiatric issues (OR = 1.22, 95% CI = 1.16-1.27). Interrupted time-series analysis showed that reformulation was associated with an immediate effect on sex, severity, accidental poisoning and unknown intent poisoning, although these were not sustained over time. Alcohol involvement in the attendance (OR = 1.43, 95% CI = 1.17-1.74, i.e. an average increase in the odds of 43% per year), Glasgow Coma Scale (OR = 1.28, 95%CI 1.04 - 1.57), a previous history of psychiatric issues (OR = 0.80, 95% CI = 0.70-0.92, i.e. an average decrease in the odds of 20% per year, heroin involvement (OR = 0.22, 95% CI = 0.05 - 0.98) and illicit drug use (OR = 0.45, 95% CI = 0.23 - 0.87) showed statistically significant relative changes following the reformulation.

CONCLUSIONS

The characteristics of oxycodone presentations in Australian ambulances attendances appear to be changing over time, including more female presentations; increasing alcohol use, extramedical use of non-opioid pharmaceuticals and suicidal thoughts or behaviours and decreasing heroin and illicit drug involvement.

Comparing rates and characteristics of ambulance attendances related to extramedical use of pharmaceutical opioids in Australia: a protocol for a retrospective observational study

INTRODUCTION AND AIMS

Extramedical use of, and associated harms with pharmaceutical opioids are common. Analysis of coded ambulance clinical records provides a unique opportunity to examine a national population-level indicator of relative harms. This protocol describes an observational study with three aims: (1) to compare supply adjusted rates of pharmaceutical opioid-related ambulance attendances for buprenorphine, codeine, fentanyl, oxycodone, oxycodone-naloxone, morphine, pethidine, tramadol and tapentadol; (2) to compare presentation characteristics for these commonly used pharmaceutical opioids and (3) to describe the context surrounding ambulance presentations related to oxycodone, a widely used opioid with an established abuse liability, and tapentadol, a more recent 'atypical' opioid on the Australian market, with fewer studies that have directly examined signals of extramedical use.

METHOD

Trained coders extract data from clinical records for ambulance presentations relating to extramedical use of commonly used pharmaceutical opioids. These data form the basis of a large, national database that captures alcohol-related and drug-related harms. Supply adjusted rates of presentations will be examined using Poisson regression. Multinomial logistic regression will be used to compare severity and other characteristics of attendances relating to different pharmaceutical opioids. Tapentadol-related and oxycodone-related cases will be qualitatively examined to understand the situationally specific contexts of the ambulance attendances outside of the characteristics captured in routinely coded variables.

ETHICS AND DISSEMINATION

Ethics approval related to analysis of ambulance attendance data was obtained from the Eastern Health Human Research Ethics Committee (E122 08-09), with an amendment specific to the qualitative analysis. Findings will be submitted for peer review in 2019. The understanding of risk profiles in real-world settings is of international public health importance. The analysis and publication of findings from this national dataset of clinical records will provide one of the most nuanced analyses to date of relative harms across nine pharmaceutical opioids over a 6-year period.

Illicit use of opioid substitution drugs: prevalence, user characteristics, and the association with non-fatal overdoses

BACKGROUND AND AIMS

Diversion of opioid substitution drugs (OSD) is of public concern. This study examined the prevalence, frequency, and predictors of illicit OSD use in a group of injecting drug users (IDUs) and assessed if such use was associated with non-fatal overdoses.

METHODS

Semi-annual cross-sectional interviews conducted in Oslo, Norway (2006-2013), from 1355 street-recruited IDUs. Hurdle, logistic, and multinomial regression models were employed.

RESULTS

Overall, 27% reported illicit OSD use in the past four weeks; 16.8% methadone, 12.5% buprenorphine, and 2.9% both drugs. Almost 1/10 reported at least one non-fatal overdose in the past four weeks, and roughly 1/3 reported such experience in the past year. Use of additional drugs tended to be equally, or more prevalent among illicit OSD users than other IDUs. In terms of illicit OSD use being a risk factor for non-lethal overdoses, our results showed significant associations only for infrequent buprenorphine use (using once or less than once per week). Other factors associated with non-fatal overdoses included age, education, homelessness, as well as the benzodiazepines, stimulants, and heroin use.

CONCLUSIONS

Users of diverted OSD may represent a high-risk population, as they used more additional drugs and used them more frequently than other IDUs. However, illicit OSD use may be less harmful than previously assumed. After accounting for an extensive set of covariates, only infrequent illicit buprenorphine use, but not methadone use, was associated with non-fatal overdoses.

Utilizing buprenorphine-naloxone to treat illicit and prescription-opioid dependence

OBJECTIVES

To review current evidence on buprenorphine-naloxone (bup/nx) for the treatment of opioid-use disorders, with a focus on strategies for clinical management and office-based patient care.

QUALITY OF EVIDENCE

Medline and the Cochrane Database of Systematic Reviews were searched. Consensus reports, guidelines published, and other authoritative sources were also included in this review. Apart from expert guidelines, data included in this review constitute level 1 evidence.

FINDINGS

Bup/nx is a partial μ-opioid agonist combined with the opioid antagonist naloxone in a 4:1 ratio. It has a lower abuse potential, carries less stigma, and allows for more flexibility than methadone. Bup/nx is indicated for both inpatient and ambulatory medically assisted withdrawal (acute detoxification) and long-term substitution treatment (maintenance) of patients who have a mild-to-moderate physical dependence. A stepwise long-term substitution treatment with regular monitoring and follow-up assessment is usually preferred, as it has better outcomes in reducing illicit opioid use, minimizing concomitant risks such as human immunodeficiency virus and hepatitis C transmission, retaining patients in treatment and improving global functioning.

CONCLUSION

Bup/nx is safe and effective for opioid detoxification and substitution treatment. Its unique pharmaceutical properties make it particularly suitable for office-based maintenance treatment of opioid-use disorder.

Survey of methadone-drug interactions among patients of methadone maintenance treatment program in Taiwan

BACKGROUND

Although methadone has been used for the maintenance treatment of opioid dependence for decades, it was not introduced in China or Taiwan until 2000s. Methadone-drug interactions (MDIs) have been shown to cause many adverse effects. However, such effects have not been scrutinized in the ethnic Chinese community.

METHODS

The study was performed in two major hospitals in southern Taiwan. A total of 178 non-HIV patients aged ≥ 20 years who had participated in the Methadone Maintenance Treatment Program (MMTP) ≥ 1 month were recruited. An MDI is defined as concurrent use of drug(s) with methadone that may result in an increase or decrease of effectiveness and/or adverse effect of methadone. To determine the prevalence and clinical characteristics of MDIs, credible data sources, including the National Health Insurance (NHI) database, face-to-face interviews, medical records, and methadone computer databases, were linked for analysis. Socio-demographic and clinical factors associated with MDIs and co-medications were also examined.

RESULTS

128 (72%) MMTP patients took at least one medication. Clinically significant MDIs included withdrawal symptoms, which were found among MMTP patients co-administered with buprenorphine or tramadol; severe QTc prolongation effect, which might be associated with use of haloperidol or droperidol; and additive CNS and respiratory depression, which could result from use of methadone in combination with chlorpromazine or thioridazine. Past amphetamine use, co-infection with hepatitis C, and a longer retention in the MMTP were associated with increased odds of co-medication. Among patients with co-medication use, significant correlates of MDIs included the male gender and length of co-medication in the MMTP.

CONCLUSIONS

The results demonstrate clinical evidence of significant MDIs among MMTP patients. Clinicians should check the past medical history of MMTP clients carefully before prescribing medicines. Because combinations of methadone with other psychotropic or opioid medications can affect treatment outcomes or precipitate withdrawal symptoms, clinicians should be cautious when prescribing these medications to MMTP patients and monitor the therapeutic effects and adverse drug reactions. Although it is difficult to interconnect medical data from different sources for the sake of privacy protection, the incumbent agency should develop pharmacovigilant measures to prevent the MDIs from occurring. Physicians are also advised to check more carefully on the medication history of their MMTP patients.

Buprenorphine-based regimens and methadone for the medical management of opioid dependence: selecting the appropriate drug for treatment

Maintenance therapy with methadone or buprenorphine-based regimens reduces opioid dependence and associated harms. The perception that methadone is more effective than buprenorphine for maintenance treatment has been based on low buprenorphine doses and excessively slow induction regimens used in early buprenorphine trials. Subsequent studies show that the efficacy of buprenorphine sublingual tablet (Subutex®) or buprenorphine/naloxone sublingual tablet (Suboxone®) is equivalent to that of methadone when sufficient buprenorphine doses, rapid induction, and flexible dosing are used. Although methadone remains an essential maintenance therapy option, buprenorphine-based regimens increase access to care and provide safer, more appropriate treatment than methadone for some patients.

Prospective comparative assessment of buprenorphine overdose with heroin and methadone: clinical characteristics and response to antidotal treatment

Buprenorphine is a partial opioid agonist with a "ceiling effect" for respiratory depression. Despite this, it has been associated with severe overdoses. Conflicting data exist regarding its response in overdose to naloxone. We compared clinical overdose characteristics of buprenorphine with heroin and methadone and assessed responses to naloxone and flumazenil. Patients admitted to two intensive care units with severe opioid overdoses were enrolled into this 4-year prospective study. Urine and blood toxicological screening were performed to identify overdoses involving predominantly buprenorphine, heroin, or methadone. Eighty-four patients with heroin (n = 26), buprenorphine (n = 39), or methadone (n = 19) overdoses were analyzed. In the buprenorphine group, sedative drug coingestions were frequent (95%), whereas in the methadone group, suicide attempts were significantly more often reported (p = .0007). Buprenorphine overdose induced an opioid syndrome not differing significantly from heroin and methadone in mental status (as measured by Glasgow Coma Score) or arterial blood gases. Mental status depression was not reversed in buprenorphine overdoses with naloxone (0.4-0.8 mg) but did improve with flumazenil (0.2-1 mg) if benzodiazepines were coingested. In conclusion, buprenorphine overdose causes an opioid syndrome clinically indistinguishable from heroin and methadone. Although mental status and respiratory depression are often unresponsive to low-dose naloxone, flumazenil may be effective in buprenorphine overdoses involving benzodiazepines.