Predictors of opioid overdose during the COVID-19 pandemic: The role of relapse, treatment access and nonprescribed buprenorphine/naloxone

INTRODUCTION

Emerging data indicate a disproportionate increase in overdose deaths since the onset of COVID-19. Speculation about causes for the increase center on rising drug use, illicit drug supply changes, and reduced treatment access. Possible overdose mitigation factors include reduced federal MOUD prescribing restrictions, naloxone distribution programs, and increased use of telehealth. Similarly, nonprescribed buprenorphine (NPB) use, increasingly described as a harm reduction strategy in the absence of treatment, may have moderated overdose risk. This study explored factors associated with pandemic-related overdose in people who use opioids (PWUO) in New Jersey.

METHODS

We surveyed 342 PWUO from March to May 2021. Approximately 50 % of our sample was treated at some time since the COVID-19 emergency declaration in March 2020. The risk and protective factors associated with overdose were identified using Pearson's chi square test and ANOVA and tested in a series of multivariable logistic regression models for the full sample and the subsample of PWUO treated during the pandemic.

RESULTS

Forty-eight percent of respondents increased their drug use during the pandemic, including 32 % who relapsed after previous abstinence. Fifteen percent overdosed at least once since March 2020. In the full sample, overdose was associated with Hispanic ethnicity (AOR = 3.51; 95 % CI = 1.22-10.11), pre-pandemic overdose (AOR = 6.75; 95 % CI = 3.03-15.02), lack/loss of medical insurance (AOR = 3.02; 95 % CI = 1.01-9.02), relapse (AOR = 2.94; 95 % CI = 1.36-6.36), and nonprescribed use of buprenorphine/naloxone (AOR = 3.16; 95 % CI = 1.49-6.70). The study found similar trends in the treatment sample, with the exceptions that heroin/fentanyl use also predicted overdose (AOR = 3.43; 95 % CI = 1.20-9.78) and the association of overdose with nonprescribed buprenorphine/naloxone was stronger (AOR = 4.91; 95 % CI = 2.01-12.03). Potential mitigating factors, such as take-home methadone and telehealth, were not significant.

CONCLUSIONS

Relapse during the pandemic was widespread and a significant contributor to overdose. Lack/loss of medical insurance further exacerbated the risk. Despite the growing literature reporting "therapeutic" use of NPB, people using nonprescribed buprenorphine/naloxone in the current study experienced up to five times the risk of overdose as nonusers. This finding suggests that, despite therapeutic intent, PWUO may be using NPB in ways that are ineffectual for addiction management, especially in the context of changing buprenorphine induction protocols in the context of fentanyl.

Buprenorphine and its formulations: a comprehensive review

Buprenorphine, a novel long-acting analgesic, was developed with the intention of two purposes: analgesia and opioid use disorder. Regarding its pharmacodynamics, it is a partial agonist at mu receptors, an inverse agonist at kappa receptors, and an antagonist at delta receptors. For the purpose of analgesia, three formulations of buprenorphine were developed: IV/IM injectable formulation (Buprenex®), transdermal patch formulation (Butrans®), and buccal film formulation (Belbuca®). Related to opioid dependence, the formulations developed were subcutaneous extended release (Sublocade®), subdermal implant (Probuphine®), and sublingual tablets (Subutex®). Lastly, in order to avoid misuse of buprenorphine for opioid dependence, two combination formulations paired with naloxone were developed: film formulation (Suboxone®) and tablet formulation (Zubsolv®). In this review, we present details of each formulation along with their similarities and differences between each other and clinical considerations.

Polyvinylpyrrolidone deposition disease in patients with intravenous opioid use: a case series

The polymer polyvinylpyrrolidone (PVP) is an excipient widely used in prescription drugs. Depending on the molecular weight (MW), parenterally administered PVP may accumulate in various tissues. Consequently, moderate and high MW PVP have only been used in oral preparations since the late 1970s. Surprisingly, starting in 2009, pathology departments in Norway received biopsies revealing PVP deposition, all from patients with a history of intravenous drug use. We identified 13 patients with PVP deposition and re-evaluated 31 biopsies and two autopsies. Common indications for biopsy were renal insufficiency, anemia, pathological fractures, and abdominal complaints. We observed PVP deposits in all biopsies (kidney, hematopoietic bone marrow, bone, gastrointestinal tract, lymph node, and skin) and all sampled tissue from the autopsies. Overall, the clinical findings could be related to PVP deposits in the biopsies. In the most seriously affected patients, PVP deposition caused severe organ dysfunction and contributed to the fatal outcomes of two patients. All patients except for one were prescribed opioid substitution drugs (OSDs), and most of the patients admitted to having injected such medications. Several OSDs contain PVP. One methadone formulation that was marketed in Norway from 2007 to 2014 contained large amounts of very high MW PVP, making it the most likely source of PVP deposition. Although the presumed source of PVP in these patients has now been withdrawn from the market, pathologists should be aware of PVP deposits when evaluating biopsies from this patient group.

Case Report: Polyvinylpyrrolidone deposition disease from repeated injection of opioid substitution drugs: report of a case with a fatal outcome

Background: Intravenous injection of oral opioid substitution drugs (OSD) is widespread among injecting drug users. Several OSDs contain the polymer polyvinylpyrrolidone (PVP) as an excipient. Parenterally administered PVP of high molecular weight may accumulate in tissues and organs. This phenomenon was first described in the 1950s, when PVP was utilised in medication for parenteral use. We report a case of an opioid-addicted patient with extensive PVP-deposition caused by repeated injections of OSDs. Case presentation: A 30-year-old male drug addicted patient in opioid substitution therapy (OST) was repeatedly referred to his local hospital in a poor general condition. Work-up revealed severe normocytic anaemia, renal insufficiency, pancreas insufficiency and pathological fractures. Biopsies from fractured bones, bone marrow and gastric mucosa showed extensive infiltrates of histiocytes with intracytoplasmic vacuoles. Vacuole content stained slightly bluish in hematoxylin and eosin stain, red in Congo red stain and black in periodic acid methenamine silver stain. The morphological appearance and staining properties were in accordance with the diagnosis of PVP deposition. The patient had been injecting both buprenorphine tablets and a specific methadone syrup for several years. The methadone syrup contained large amounts of high molecular weight PVP, making it the most likely cause of the deposition. His health quickly deteriorated and he died, impaired by multi-organ failure and cachexia, five years after the first diagnosis of PVP-deposition. The autopsy revealed extensive PVP-deposition in all sampled organs and tissues. Conclusions: Histological investigation and the correct identification of PVP in the biopsies led to the discovery of a severe adverse effect from long-standing misuse of a drug. The disseminated PVP deposition likely contributed to multi-organ dysfunction and cachexia with a fatal outcome. The deposited PVP likely originated from repeated injections of a certain methadone syrup.

Case Report: Polyvinylpyrrolidone deposition disease from repeated injection of opioid substitution drugs: report of a case with a fatal outcome

Background: Intravenous injection of oral opioid substitution drugs (OSD) is widespread among injecting drug users. Several OSDs contain the polymer polyvinylpyrrolidone (PVP) as an excipient. Parenterally administered PVP of high molecular weight may accumulate in tissues and organs. This phenomenon was first described in the 1950s, when PVP was utilised in medication for parenteral use. We report a case of an opioid-addicted patient with extensive PVP-deposition caused by repeated injections of OSDs. Case presentation: A 30-year-old male drug addicted patient in opioid substitution therapy (OST) was repeatedly referred to his local hospital in a poor general condition. Work-up revealed severe normocytic anaemia, renal insufficiency, pancreas insufficiency and pathological fractures. Biopsies from fractured bones, bone marrow and gastric mucosa showed extensive infiltrates of histiocytes with intracytoplasmic vacuoles. Vacuole content stained slightly bluish in hematoxylin and eosin stain, red in Congo red stain and black in periodic acid methenamine silver stain. The morphological appearance and staining properties were in accordance with the diagnosis of PVP deposition. The patient had been injecting both buprenorphine tablets and a specific methadone syrup for several years. The methadone syrup contained large amounts of high molecular weight PVP, making it the most likely cause of the deposition. His health quickly deteriorated and he died, impaired by multi-organ failure and cachexia, five years after the first diagnosis of PVP-deposition. The autopsy revealed extensive PVP-deposition in all sampled organs and tissues. Conclusions: Histological investigation and the correct identification of PVP in the biopsies led to the discovery of a severe adverse effect from long-standing misuse of a drug. The disseminated PVP deposition likely contributed to multi-organ dysfunction and cachexia with a fatal outcome. The deposited PVP likely originated from repeated injections of a certain methadone syrup.

Characterization of diverted buprenorphine use among adults entering corrections-based drug treatment in Kentucky

BACKGROUND

Illicit, medically unsupervised use of buprenorphine (i.e., "diverted use") among vulnerable and underserved populations, such as corrections-involved adults, remains underexplored.

METHODS

Survey data (2016-2017) collected as part of a clinical assessment of incarcerated adults entering corrections-based substance use treatment in Kentucky were analyzed. For years examined, 12,915 completed the survey. Removing cases for participants who did not reside in Kentucky for >6 months during the one-year pre-incarceration period (n = 908) resulted in a final sample size of 12,007.

RESULTS

Over a quarter of the sample reported past-year diverted buprenorphine use prior to incarceration and 21.8 % reported use during the 30-days prior to incarceration, using 6.5 months and 14.3 days on average, respectively. A greater proportion of participants who reported diverted buprenorphine use had previously been engaged with some substance use treatment (77.0 %) and reported greater perceived need for treatment (79.4 %) compared to those who did not report use. Use was more likely among participants who were younger, white, male, and who reported rural or Appalachian residence. Diverted buprenorphine users also evidenced extensive polydrug use and presented with greater substance use disorder severity. Non-medical prescription opioid, heroin, and diverted methadone use were associated with increased odds of diverted buprenorphine use while kratom was not. Diverted methadone use was associated with a 252.9 % increased likelihood of diverted buprenorphine use.

CONCLUSIONS

Diverted buprenorphine use among participants in this sample was associated with concerning high-risk behaviors and may indicate barriers to accessing opioid agonist therapies for corrections-involved Kentucky residents, particularly those in rural Appalachia.

Medication Treatment of Opioid Use Disorder

Opioid use disorder (OUD) is a chronic, relapsing condition, often associated with legal, interpersonal, and employment problems. Medications demonstrated to be effective for OUD are methadone (a full opioid agonist), buprenorphine (a partial agonist), and naltrexone (an opioid antagonist). Methadone and buprenorphine act by suppressing opioid withdrawal symptoms and attenuating the effects of other opioids. Naltrexone blocks the effects of opioid agonists. Oral methadone has the strongest evidence for effectiveness. Longer duration of treatment allows restoration of social connections and is associated with better outcomes. Treatments for OUD may be limited by poor adherence to treatment recommendations and by high rates of relapse and increased risk of overdose after leaving treatment. Treatment with methadone and buprenorphine has the additional risk of diversion and misuse of medication. New depot and implant formulations of buprenorphine and naltrexone have been developed to address issues of safety and problems of poor treatment adherence. For people with OUD who do not respond to these treatments, there is accumulating evidence for supervised injectable opioid treatment (prescribing pharmaceutical heroin). Another medication mode of minimizing risk of overdose is take-home naloxone. Naloxone is an opioid antagonist used to reverse opioid overdose, and take-home naloxone programs aim to prevent fatal overdose. All medication-assisted treatment is limited by lack of access and by stigma. In seeking to stem the rising toll from OUD, expanding access to approved treatment such as methadone, for which there remains the best evidence of efficacy, may be the most useful approach.

Overdose Risk and Client Characteristics Associated With the Injection of Buprenorphine at a Medically Supervised Injecting Center in Sydney, Australia

Background: Buprenorphine and buprenorphine/naloxone (BNX) were developed to improve the safety profile of opioid substitution treatment (OST) and reduce diversion and injection, yet continue to be injected, despite the risk of harm. Previous studies examining injection of these substances have relied on self-reported injection and overdose. Using data from the Uniting Medically Supervised Injecting Center (MSIC) in Sydney, this study aimed to assess the overdose risk associated with the use of buprenorphine and BNX and identify factors associated with injecting. Methods: Client data routinely collected from MSIC, a drug consumption room where clients can legally inject drugs under supervision, was used. Odds ratios (OR) to assess the risk of overdose and their associated 95% confidence intervals (95%CI) were calculated and compared to other substances. Univariate analysis using χ-square and multivariate logistic regressions were used to determine characteristics associated with buprenorphine and BNX injection. Results: Data from 1,020,782 injections by 15,832 individuals were analyzed. Risk of overdose was low for buprenorphine compared to other substances (OR 0.16; 95%CI: 0.07-0.19) and no overdoses occurred when BNX was injected. Injection of both buprenorphine and BNX was associated with male gender, homelessness, no income/reliance upon government payments, and prior imprisonment. Conclusions: Buprenorphine and BNX continue to be injected, albeit in small numbers. This is the first study to report on injection and overdose risk using direct observation, and has confirmed the lower overdose risk. MSIC clients who inject buprenorphine and BNX tend to be marginalized and may benefit from targeted harm reduction measures.

Understanding the use of diverted buprenorphine

BACKGROUND

Buprenorphine is approved in many countries for the treatment of opioid use disorder (OUD), but problems with diversion and abuse exist. There is a need to understand how and why patients use diverted buprenorphine, and whether barriers to access contribute to illicit use.

METHODS

Adults >18 years with DSM-IV criteria for substance use disorder and primarily using an opioid completed the online Survey of Key Informants' Patients (SKIP) between August and September 2016. The survey included closed- and open-ended questions regarding reasons for buprenorphine use with and without a prescription, sources of buprenorphine, route of administration, and barriers to treatment.

RESULTS

Of 303 respondents, 175 (58%) reported a history of diverted buprenorphine use, 65 (37%) of whom reported never receiving a prescription. The most common reasons for illicit buprenorphine use were consistent with therapeutic use: to prevent withdrawal (79%), maintain abstinence (67%), or self-wean off drugs (53%). Approximately one-half (52%) reported using buprenorphine to get high or alter mood, but few (4%) indicated that it was their drug of choice. Among respondents who had used diverted buprenorphine, 33% reported that they had issues finding a doctor or obtaining buprenorphine on their own. Most (81%) of these participants indicated they would prefer using prescribed buprenorphine, if available.

CONCLUSIONS

Although 58% of survey respondents reported a history of using diverted buprenorphine, the most frequently cited reasons for non-prescription use were consistent with therapeutic use. Diversion was partially driven by barriers to access, and an unmet need for OUD treatment persists.

The relationship between diversion-related attitudes and sharing and selling buprenorphine

OBJECTIVE

Buprenorphine medication-assisted treatment (B-MAT) is an efficacious and popular outpatient treatment for opioid use disorder. However, the likelihood of buprenorphine diversion is a public health concern. We examined the relationship between attitudes toward diversion as predictors of both sharing and selling buprenorphine.

METHOD

Participants (n=476) were patients undergoing short-term inpatient opioid detoxification. Multinomial logistic regression was used to estimate the adjusted association of sharing and selling buprenorphine with demographics, substance use behaviors, and attitudes toward sharing and selling buprenorphine.

RESULTS

Among the two hundred persons who had ever been prescribed buprenorphine (73.4% male, 89% heroin users), 50.5% reported they had shared buprenorphine and 28.0% reported they had sold buprenorphine. Controlling for other covariates, the odds of sharing buprenorphine were 3.17 (95% CI 1.21; 8.32) times higher for persons who agreed that it was "right to share buprenorphine with dope sick friends" than for those who did not agree with this attitude. Attitudes toward selling (OR 2.92; 95% CI 1.35; 6.21) and sharing (OR 4.12; 95% CI 1.64; 10.32) buprenorphine were the only significant correlates of selling, with the odds of selling exponentially greater among persons with favorable attitudes toward sharing or selling buprenorphine.

CONCLUSIONS

Although considered diversion, sharing B-MAT is normative among B-MAT patients. Assessing B-MAT patients' attitudes about diversion may help identify patients requiring enhanced oversight, education, or intervention aimed at modifying attitudes to reduce their likelihood to share or sell buprenorphine.

Factors associated with non-adherence and misuse of opioid maintenance treatment medications and intoxicating drugs among Finnish maintenance treatment patients

BACKGROUND

The intravenous (IV) use of opioid maintenance treatment (OMT) medications and other intoxicating drugs among OMT patients is a challenge for many OMT units and affects treatment outcomes. The aim of this study is to examine factors associated with IV use of OMT medications and other intoxicating drugs among Finnish OMT patients.

METHODS

A cross-sectional study was conducted among all Finnish OMT patients of whom 60% (n=1508) participated. The data were collected by anonymous questionnaire. Binominal regression analysis with unadjusted and adjusted ORs was conducted to evaluate predictors for IV use.

FINDINGS

Factors associated with the injection of a patient's own OMT medication were: being treated with buprenorphine-naloxone (BNX) (OR 2.60, p=0.005) with a low dose (<9.0mg/day; OR 5.70, p<0.001) and being treated in a health-care centre (OR 2.03, p=0.029). Factors associated with the injection of illicit OMT medications were: being treated with BNX (OR 5.25, p<0.001) with a low dose (<9.0mg/day; OR 2.89, p=0.017), lack of psychosocial support (OR 2.62, p<0.001) and concurrent use of psychotropic medications from illicit sources (OR 4.28, p<0.001). Associated factors for the injection of other intoxicating drugs were: concurrent use of illicit drugs (OR 1.72, p=0.015), psychotropic medications from illicit sources (OR 4.78, p<0.001) and from a doctor (OR 1.93, p=0.004).

CONCLUSIONS

More effort should be made to reduce concurrent injecting use during OMT. This may be done by addressing concurrent substance use orders more effectively, by ensuring that patients receive an optimal BNX dose and by providing more psychosocial support.

Diversion and injection of buprenorphine-naloxone film two years post-introduction in Australia

INTRODUCTION AND AIMS

We report 2 years of post-marketing surveillance of the diversion and injection of buprenorphine-naloxone (BNX) film following its introduction in 2011.

DESIGN AND METHODS

Interviews were conducted with people who inject drugs regularly (PWID) (2004-2013), opioid substitution therapy clients (2013, n = 492) and key experts (n = 44). Key outcomes were unsanctioned removal of supervised doses, diversion, injection and street price. Prevalence of past 6-month injection among PWID was adjusted for background availability of opioid substitution therapy medications using sales data.

RESULTS

Among out-of-treatment PWID, the levels of regular (weekly+) BNX film injection were comparable to methadone and BNX tablets, and lower than mono-buprenorphine, adjusting for background availability. Fewer BNX film clients [3%; 95% (CI) 1-5] regularly injected their medication than mono-buprenorphine clients (25%; 95% CI 11-39), but at levels equivalent to those among methadone (3%; 95% CI 1-6) and BNX tablet clients (2%; 95% CI 0-6). Key experts perceived BNX film needed less supervised dosing time as it dissolved rapidly and was harder to remove from the mouth than sublingual tablets; however, removal of supervised doses was higher among BNX film clients (15%; 95% CI: 10-20) than methadone clients (3%; 95% CI 1-6), and not significantly different from BNX tablet (11%; 95% CI 2-21) and mono-buprenorphine clients (31%; 95% CI 16-46).

DISCUSSION AND CONCLUSIONS

Two years post-introduction, levels of BNX film diversion and injection remained comparable with those for methadone and BNX tablets, and lower than mono-buprenorphine. We found no evidence that BNX film has lower non-adherence and diversion than the tablet formulation. [Larance B, Mattick R, Ali R, Lintzeris N, Jenkinson R, White N, Kihas I, Cassidy R, Degenhardt L. Diversion and injection of buprenorphine-naloxone film two years post-introduction in Australia. Drug Alcohol Rev 2015].

A review of buprenorphine diversion and misuse: the current evidence base and experiences from around the world

Outpatient opioid addiction treatment with sublingual buprenorphine pharmacotherapy has rapidly expanded in the United States and abroad, and, with this increase in medication availability, there have been increasing concerns about its diversion, misuse, and related harms. This narrative review defines the behaviors of diversion and misuse, examines how the pharmacology of buprenorphine alone and in combination with naloxone influence its abuse liability, and describes the epidemiological data on buprenorphine diversion and intravenous misuse, risk factors for its intravenous misuse, and the unintended consequences of misuse and diversion. Physician practices to prevent, screen for, and therapeutically respond to these behaviors, which are a form of medication nonadherence, are discussed, and gaps in knowledge are identified. Outpatient opioid addiction treatment with sublingual buprenorphine pharmacotherapy experiences from other countries that have varied health care systems, public policies, and access to addiction treatment are shared to make clear that diversion and misuse occur across the world in various contexts, for many different reasons, and are not limited to buprenorphine. Comparisons are made with other opioids with known abuse liability and medications with no known abuse. The objective was to facilitate understanding of diversion and misuse so that all factors influencing their expression (patient and provider characteristics and public policy) can be appreciated within a framework that also recognizes the benefits of addiction treatment. With this comprehensive perspective, further careful work can help determine how to minimize these behaviors without eroding the current benefits realized through improved addiction treatment access and expansion.

Pharmacological maintenance treatments of opiate addiction

For people seeking treatment, the course of heroin addiction tends to be chronic and relapsing, and longer duration of treatment is associated with better outcomes. Heroin addiction is strongly associated with deviant behaviour and crime, and the objectives in treating heroin addiction have been a blend of humane support, rehabilitation, public health intervention and crime control. Reduction in street heroin use is the foundation on which all these outcomes are based. The pharmacological basis of maintenance treatment of dependent individuals is to minimize withdrawal symptoms and attenuate the reinforcing effects of street heroin, leading to reduction or cessation of street heroin use. Opioid maintenance treatment can be moderately effective in suppressing heroin use, although deviations from evidence-based approaches, particularly the use of suboptimal doses, have meant that treatment as delivered in practice may have resulted in poorer outcomes than predicted by research. Methadone treatment has been 'programmatic', with a one-size-fits-all approach that in part reflects the perceived need to impose discipline on deviant individuals. However, differences in pharmacokinetics and in side-effects mean that many patients do not respond optimally to methadone. Injectable diamorphine (heroin) provides a more reinforcing medication for some 'nonresponders' and can be a valuable option in the rehabilitation of demoralized, socially excluded individuals. Buprenorphine, a partial agonist, is a less reinforcing medication with different side-effects and less risk of overdose. Not only is it a different medication, but also it can be used in a different paradigm of treatment, office-based opioid treatment, with less structure and offering greater patient autonomy.

The diversion and injection of a buprenorphine-naloxone soluble film formulation

BACKGROUND

We compared the diversion and injection of a new formulation of buprenorphine, a buprenorphine-naloxone film product (BNX film), with buprenorphine-naloxone tablets (BNX tablets), mono-buprenorphine (BPN) and methadone (MET) in Australia.

METHODS

Surveys were conducted with people who inject drugs regularly (PWID) (2004-2012) and opioid substitution treatment (OST) clients (2012, N=543). Key outcome measures: the unsanctioned removal of supervised doses, diversion, injection, motivations, drug liking and street price. Levels of injection among PWID were adjusted for background availability of medication using sales data. Doses not taken as directed by OST clients were adjusted by total number of daily doses dispensed.

RESULTS

Among out-of-treatment PWID, levels of injection for BNX film were comparable to those for MET and BNX tablet formulations, adjusting for background availability; BPN injecting levels were higher. Among OST clients, recent injecting of one's medication was similar among clients in all OST types; weekly or more frequent injection of prescribed doses was reported by fewer BNX film clients (3%; 95% CI: 1-6) than BPN clients (11%; 95% CI: 3-17), but at levels similar to those observed among MET and BNX tablet clients. The proportion of BNX film doses injected was lower than that for BPN and BNX tablets, and equivalent to that for MET. The majority of BNX film doses injected by OST clients were unsupervised doses, although some injection of supervised doses of BNX film did occur. The median price of all buprenorphine forms on the illicit market was the same.

CONCLUSIONS

Non-adherence and diversion of the BNX film formulation was similar to MET and BNX tablet formulations; BPN had higher levels of all indicators of non-adherence and diversion.

A randomised controlled trial of sublingual buprenorphine-naloxone film versus tablets in the management of opioid dependence

BACKGROUND

Buprenorphine-naloxone sublingual film was introduced in 2011 in Australia as an alternative to tablets. This study compared the two formulations on subjective dose effects and equivalence, trough plasma levels, adverse events, patient satisfaction, supervised dosing time, and impact upon treatment outcomes (substance use, psychosocial function).

METHODS

92 buprenorphine-naloxone tablet patients were recruited to this outpatient multi-site double-blind double-dummy parallel group trial. Patients were randomised to either tablets or film, without dose changes, over a 31 day period.

RESULTS

No significant group differences were observed for subjective dose effects, trough plasma buprenorphine or norbuprenorphine levels, adverse events and treatment outcomes. Buprenorphine-naloxone film took significantly less time to dissolve than tablets (173±71 versus 242±141s, p=0.007, F=7.67).

CONCLUSIONS

The study demonstrated dose equivalence and comparable clinical outcomes between the buprenorphine-naloxone film and tablet preparations, whilst showing improved dispensing times and patient ratings of satisfaction with the film.

Twelve-year trend in treatment seeking for buprenorphine abuse in Finland

BACKGROUND

Buprenorphine abuse is becoming increasingly common worldwide. However, large-scale long-term studies of buprenorphine abuse are lacking. The objective of this study was to examine the trend in characteristics of clients seeking treatment for buprenorphine abuse and compare them to those seeking treatment for heroin and amphetamine abuse.

METHODS

A 12-year descriptive study was conducted at the Helsinki Deaconess Institute (HDI), a public utility foundation responsible for providing treatment for substance abuse in the greater Helsinki area. All clients seeking treatment between 31 January 1997 and 31 August 2008 received a structured clinical interview concerning demographic characteristics and abuse patterns. Characteristics of clients who reported that their primary drug of abuse was buprenorphine (n=780) were compared to those whose primary drug of abuse was either heroin (n=598) or amphetamine (n=1249).

RESULTS

The annual proportion of buprenorphine clients increased from 3.0% in 1998 to 38.4% in 2008. Daily abuse (73.8%) and intravenous administration (80.6%) were common among buprenorphine clients. Concurrent abuse of prescription medications (p<0.001), stimulants (p=0.001) and alcohol (p<0.001) increased from 1997 to 2008. Treatment seeking for heroin abuse declined to approximately 1% of clients annually after 2002. Buprenorphine clients were more likely to be daily users of their primary drug (p<0.001), abuse prescription medications (p<0.001) and administer drugs intravenously (p=0.001 from 1997 to 2001) compared to heroin and amphetamine clients.

CONCLUSIONS

Our results highlight the increasing abuse of buprenorphine in Finland. Buprenorphine clients had risky abuse patterns in terms of daily use and intravenous administration. Concurrent substance abuse increased during the study period.

Use and misuse of opioid replacement therapies: a Queensland study

Buprenorphine/naloxone has recently been introduced in Australia and is available for unsupervised dosing within Queensland. A retrospective observational study of data collected during 2000-2007 for clients obtaining injecting equipment from the Brisbane Harm Reduction Centre in Queensland is presented. The numbers of service occasions and needles and syringes were used as surrogate drug use measures. Buprenorphine and naloxone were misused at lower rates when compared with buprenorphine and methadone. Furthermore, the misuse of opioid replacement therapies represented less than 5% of all illicit opioid injections. Implications and study limitations are discussed.

Illicit use of buprenorphine/naloxone among injecting and noninjecting opioid users

OBJECTIVES

We examined the use, procurement, and motivations for the use of diverted buprenorphine/naloxone among injecting and noninjecting opioid users in an urban area.

METHODS

A survey was self-administered among 51 injecting opioid users and 49 noninjecting opioid users in Providence, RI. Participants were recruited from a fixed-site syringe exchange program and a community outreach site between August and November 2009.

RESULTS

A majority (76%) of participants reported having obtained buprenorphine/naloxone illicitly, with 41% having done so in the previous month. More injection drug users (IDUs) than non-IDUs reported the use of diverted buprenorphine/naloxone (86% vs 65%, P = 0.01). The majority of participants who had used buprenorphine/naloxone reported doing so to treat opioid withdrawal symptoms (74%) or to stop using other opioids (66%) or because they could not afford drug treatment (64%). More IDUs than non-IDUs reported using diverted buprenorphine/naloxone for these reasons. Significantly more non-IDUs than IDUs reported ever using buprenorphine/naloxone to "get high" (69% vs 32%, P < 0.01). The majority of respondents, both IDUs and non-IDUs, were interested in receiving treatment for opioid dependence, with greater reported interest in buprenorphine/naloxone than in methadone. Common reasons given for not being currently enrolled in a buprenorphine/naloxone program included cost and unavailability of prescribing physicians.

CONCLUSIONS

The use of diverted buprenorphine/naloxone was common in our sample. However, many opioid users, particularly IDUs, were using diverted buprenorphine/naloxone for reasons consistent with its therapeutic purpose, such as alleviating opioid withdrawal symptoms and reducing the use of other opioids. These findings highlight the need to explore the full impact of buprenorphine/naloxone diversion and improve the accessibility of buprenorphine/naloxone through licensed treatment providers.

The pharmacodynamic and pharmacokinetic profile of intranasal crushed buprenorphine and buprenorphine/naloxone tablets in opioid abusers

AIMS

Sublingual buprenorphine and buprenorphine/naloxone are efficacious opioid dependence pharmacotherapies, but there are reports of their diversion and misuse by the intranasal route. The study objectives were to characterize and compare their intranasal pharmacodynamic and pharmacokinetic profiles.

DESIGN

A randomized, double-blind, placebo-controlled, cross-over study.

SETTING

An in-patient research unit at the University of Kentucky.

PARTICIPANTS

Healthy adults (n = 10) abusing, but not physically dependent on, intranasal opioids.

MEASUREMENTS

Six sessions (72 hours apart) tested five intranasal doses [0/0, crushed buprenorphine (2, 8 mg), crushed buprenorphine/naloxone (2/0.5, 8/2 mg)] and one intravenous dose (0.8 mg buprenorphine/0.2 mg naloxone for bioavailability assessment). Plasma samples, physiological, subject- and observer-rated measures were collected before and for up to 72 hours after drug administration.

FINDINGS

Both formulations produced time- and dose-dependent increases on subjective and physiological mu-opioid agonist effects (e.g. 'liking', miosis). Subjects reported higher subjective ratings and street values for 8 mg compared to 8/2 mg, but these differences were not statistically significant. No significant formulation differences in peak plasma buprenorphine concentration or time-course were observed. Buprenorphine bioavailability was 38-44% and T(max) was 35-40 minutes after all intranasal doses. Naloxone bioavailability was 24% and 30% following 2/0.5 and 8/2 mg, respectively.

CONCLUSIONS

It is difficult to determine if observed differences in abuse potential between intranasal buprenorphine and buprenorphine/naloxone are clinically relevant at the doses tested. Greater bioavailability and faster onset of pharmacodynamic effects compared to sublingual administration suggests a motivation for intranasal misuse in non-dependent opioid abusers. However, significant naloxone absorption from intranasal buprenorphine/naloxone administration may deter the likelihood of intranasal misuse of buprenorphine/naloxone, but not buprenorphine, in opioid-dependent individuals.

Prescription of analgesics to patients in opioid maintenance therapy: a pharmacoepidemiological study

AIMS

The primary aim of the present study is to determine the one year periodic prevalence of dispension of different analgesics to patients in long term opioid maintenance therapy (OMT). The secondary aim is to determine to which extent non-opioid analgesics are used as first line analgesics.

DESIGN

The study is a pharmacoepidemiological study with cross sectional data and cohort data. Data on patients in long term OMT in Norway were obtained from the complete national Norwegian Prescription Database (NorPD).

FINDINGS

The analgesics with the highest one year periodic prevalence were NSAIDs (22%), codeine-paracetamol combinations (9%), paracetamol (7%) and tramadol (2.5%). During both 2007 and 2008 a total of 12% of the study population received at least one dispension of another opioid in addition to the opioid used for OMT. In 55% of the cases where OMT patients had not received an analgesic the preceding year an NSAID was the first or only dispensed analgesic whereas paracetamol-codeine was the first or only dispensed analgesic in 29% of the cases.

CONCLUSIONS

This study has documented an equally high one year periodic prevalence of opioid dispensions in OMT patients as in the general population as well as a high one year periodic prevalence of dispensions of NSAIDs. Dispension of codeine-paracetamol has a relatively high one-year prevalence and is frequently used as a first line analgesic.

The prevalence and correlates of buprenorphine inhalation amongst opioid substitution treatment (OST) clients in Australia

BACKGROUND

Diversion and injection of buprenorphine (Subutex(®)) and buprenorphine-naloxone (Suboxone(®)) have been well documented. Recent international research and local anecdotal evidence suggest that these medications are also used by other routes of administration, including smoking and snorting.

METHODS

A cross-sectional sample of 440 opioid substitution treatment (OST) clients was recruited through pharmacies and clinics in three Australian jurisdictions, and interviewed face-to-face using a structured questionnaire. Eligible participants were those aged 18 or over, who had resided in their home state for at least six months, and had been in their current treatment episode for at least 4 weeks. We compared differences in characteristics between clients who had ever inhaled (smoked or snorted) buprenorphine (including buprenorphine-naloxone) and other OST clients. Logistic regression was used to identify correlates of buprenorphine inhalation. Sixty-eight clients who had never used buprenorphine were excluded from analysis.

RESULTS

Sixty-five clients (18%) reported having ever inhaled buprenorphine, with Subutex(®) smoking being most common, reported by 50 clients (77%). In multivariable logistic regression, those who reported ever inhaling buprenorphine were significantly more likely to: be aged 35 or younger, have ever been in prison and have ever injected buprenorphine. Clients from New South Wales and Victoria were significantly less likely to have ever inhaled buprenorphine than those from South Australia.

CONCLUSIONS

Our data indicates that the inhalation of buprenorphine has occurred in a significant minority of Australian OST clients. The motivations, contexts and potential health consequences of buprenorphine use by these atypical routes of administration, particularly in a correctional setting, warrant further exploration.

Therapeutic switch to buprenorphine/naloxone from buprenorphine alone: clinical experience in an Italian addiction centre

Pharmacological therapy has an important place in the management of opioid dependence. Methadone has been the mainstay of therapy but has a number of limitations. Buprenorphine monotherapy is another option, but misuse and diversion can have negative consequences. The opioid receptor antagonist, naloxone, has been added to buprenorphine to create a combination product with a reduced potential for misuse and diversion. This study evaluated the use of buprenorphine/naloxone for 24 weeks as a pharmacological management of opioid-dependent patients after therapeutic switch from buprenorphine alone. Patients (n = 43) received sublingual tablets of buprenorphine/naloxone. The buprenorphine dose was 2-24 mg (mean 16). Patients saw a physician, including an interview using a structured data sheet, and had counselling each week. Assessments were performed at week 2 (period 1), week 6 (period 2), week 16 (period 3) and week 24 (period 4). Laboratory immunoenzymatic testing was performed weekly to detect drugs in the urine. The management of withdrawal symptoms was rated as 'satisfactory' by 67% of patients during period 1 and 91% during period 4. The majority of patients was highly satisfied with therapy and considered that buprenorphine/naloxone provided good control of cravings. Two patients dropped out of therapy, but all others continued to receive buprenorphine throughout the study. Approximately 50% of patients stated that they disliked the sensory properties (taste, colour, odour and feel) of buprenorphine/naloxone. Adverse effects were as would be expected on the basis of the mechanism of action of buprenorphine (i.e. opioid-induced constipation) and for patients undergoing drug withdrawal. Only 2% of patients attempted the intravenous misuse of buprenorphine/naloxone, none of whom experienced any gratifying effects. Opioid-dependent patients maintained on buprenorphine monotherapy can be safely switched to a sublingual buprenorphine/naloxone tablet without any loss of treatment effectiveness. Buprenorphine/naloxone can be administered in an outpatient or primary care setting, and effectively controls cravings and withdrawal symptoms. Patient satisfaction was high, making retention in treatment more likely.

Intravenous misuse of buprenorphine: characteristics and extent among patients undergoing drug maintenance therapy

Sublingual buprenorphine [Subutex(R)] is used to treat opioid dependence. However, illicit intravenous (IV) injection of buprenorphine is a widespread problem. This survey investigated the IV misuse of buprenorphine among patients receiving drug replacement therapy at the Drug Addiction Centre in Udine, Italy. All patients who were receiving treatment with buprenorphine or methadone at the Drug Addiction Centre were invited to fill in a voluntary and anonymous questionnaire consisting of five questions. The questions asked if the patient had ever misused buprenorphine intravenously, when the misuse had occurred, the patient's reasons for misusing buprenorphine, the patient's perception of their experience, and the patient's perception of how widespread IV misuse of buprenorphine is. 307 patients completed the questionnaire, 93 and 214 of whom, respectively, were receiving buprenorphine and methadone. In total, 23.12% of patients admitted an IV misuse of buprenorphine, with a significantly greater prevalence among patients currently receiving buprenorphine (35.48%) than those receiving methadone (17.75%; p < 0.001). Younger patients were also more likely to have misused buprenorphine, and tended to have done so before coming to the Drug Addiction Centre. The most frequent motivation for IV misuse was treatment of heroin addiction or withdrawal symptoms (50.71%), while only 12.67% of patients reported that their motivation was to experience pleasure or euphoria. The majority of patients who had misused buprenorphine intravenously (53.52%) had a negative experience, and methadone recipients were significantly more likely to find the experience negative than buprenorphine recipients (68.42% vs 36.36%; p = 0.007). Almost half of the patients (45.93%) thought that at least 50% of patients had taken buprenorphine by IV injection. The results of our study confirm the widespread IV misuse of buprenorphine. Misuse was most common among patients currently receiving buprenorphine treatment and younger patients. For the majority of patients, the reason for IV misuse was to treat their dependence. We believe that the prevalence of buprenorphine misuse could be reduced by adopting appropriate clinical practices and treating patients with the buprenorphine/naloxone combination rather than buprenorphine alone.

Diversion and injection of methadone and buprenorphine among clients in public opioid treatment clinics in New South Wales, Australia

A survey of 448 clients receiving opioid treatment in public clinics in Australia was conducted during 2005, exploring diversion and injection of supervised methadone and buprenorphine, frequency and reported effects of injecting, and the cost and availability of street-purchased pharmacotherapies. The rates of diversion in the preceding 12 months were over three times higher among participants receiving supervised buprenorphine (15.3%) than among those receiving supervised methadone (4.3%). While 26.5% of participants currently prescribed buprenorphine had ever injected buprenorphine, 65.9% of those prescribed methadone reported ever injecting methadone. The majority of participants did not appear to have extensive experience of injecting their medication and most expressed a preference for taking it as directed. Further research is required to determine the optimal approach for the supervised administration of buprenorphine that maximizes the benefits of treatment and minimizes harm and the risk of diversion. The study's limitations are noted.