Correlates of nonfatal overdose among treatment-seeking individuals with non-heroin opioid use disorder: Findings from a pragmatic, pan-Canadian, randomized control trial

INTRODUCTION

Misuse of prescription and synthetic opioids is a primary contributor to the escalating overdose crisis in North America. However, factors associated with nonfatal overdose (NFO) in this context are poorly understood. We examined individual and socio-structural level correlates of NFO among treatment-seeking adults with an opioid use disorder (OUD) not attributed to heroin (nonheroin opioid use disorder [NH-OUD]).

METHODS

The study drew data from OPTIMA, a pan-Canadian, multicenter, pragmatic, two-arm randomized control trial comparing supervised methadone and flexible take-home dosing buprenorphine/naloxone models of care among adults with NH-OUD conducted between 2017 and 2020. We used bivariable and multivariable logistic regression to determine factors associated with a lifetime history of NFO among participants enrolled in the trial.

RESULTS

Of 267 included participants, 154 (58%) reported a NFO in their lifetime, of whom 83 (55 %) had an NFO in the last 6 months. In multivariable analyses, positive urine drug test (UDT) for methamphetamine/amphetamine (Adjusted Odds Ratio [AOR] = 2.59; 95 % confidence interval [CI]: 1.17-5.80), positive UDT for fentanyl (AOR = 2.31; 95 % CI: 1.01-5.30), receiving income assistance (AOR = 2.17; 95 % CI: 1.18-4.09) and homelessness (AOR = 2.40; 95 % CI: 1.25-4.68) were positively associated with a lifetime history of NFO.

CONCLUSIONS

We found a high prevalence of NFO history in treatment-seeking adults with NH-OUD, particularly among participants with certain drug use patterns and markers of socio-structural marginalization at the time of enrollment. Given the known impact of prior NFO on future harms, these findings highlight the need for comprehensive care approaches that address polysubstance use and social determinants of health to mitigate future overdose risk.

Impacts of the COVID-19 pandemic on enrollment in medications for opioid use disorder (MOUD) in Vancouver, Canada: An interrupted time series analysis

BACKGROUND

In anticipation of COVID-19 related disruptions to opioid use disorder (OUD) care, new provincial and federal guidance for the management of OUD and risk mitigation guidance (RMG) for prescription of pharmaceutical opioids were introduced in British Columbia, Canada, in March 2020. This study evaluated the combined impacts of the COVID-19 pandemic and counteracting OUD policies on enrollment in medications for OUD (MOUD).

METHODS

Using data from three cohorts of people with presumed OUD in Vancouver, we conducted an interrupted time series analysis to estimate the combined effects impact of the COVID-19 pandemic and counteracting OUD policies on the prevalence of enrollment in MOUD overall, as well as in individual MOUDs (methadone, buprenorphine/naloxone, slow-release oral morphine) between November 2018 and November 2021, controlling for pre-existing trends. In sub-analysis we considered RMG opioids together with MOUD.

RESULTS

We included 760 participants with presumed OUD. In the post-COVID-19 period, MOUD and slow-release oral morphine prevalence rates showed an estimated immediate increase in level (+7.6%, 95% CI: 0.6%, 14.6% and 1.8%, 95% CI: 0.3%, 3.3%, respectively), followed by a decline in the monthly trend (-0.8% per month, 95% CI: -1.4%, -0.2% and -0.2% per month, 95% CI: -0.4, -0.1, respectively). There were no significant changes in the prevalence trends of enrollment in methadone, buprenorphine/naloxone, or when RMG opioids were considered together with MOUD.

CONCLUSIONS

Despite immediate improvements in MOUD enrollment in the post-COVID-19 period, this beneficial trend reversed over time. RMG opioids appeared to have provided additional benefits to sustain retention in OUD care.

Risk mitigation guidance and safer supply prescribing among young people who use drugs in the context of COVID-19 and overdose emergencies

Across North America, overlapping overdose and COVID-19 emergencies have had a substantial impact on young people who use drugs (YPWUD). New risk mitigation guidance (RMG) prescribing practices were introduced in British Columbia, Canada, in 2020 to allow people to decrease risk of overdose and withdrawal and better self-isolate. We examined how the prescribing of hydromorphone tablets specifically impacted YPWUD's substance use and care trajectories. Between April 2020 and July 2021, we conducted virtual interviews with 30 YPWUD who had accessed an RMG prescription of hydromorphone in the previous six months and 10 addiction medicine physicians working in Vancouver. A thematic analysis was conducted. YPWUD participants highlighted a disjuncture between risk mitigation prescriptions and the safe supply of unadulterated substances such as fentanyl, underscoring that having access to the latter is critical to reducing their reliance on street-based drug markets and overdose-related risks. They described re-appropriating these prescriptions to meet their needs, stockpiling hydromorphone so that it could be used as an “emergency backup” when they were unable to procure unregulated, illicit opioids. In the context of entrenched poverty, hydromorphone was also used to generate income for the purchase of drugs and various necessities. For some YPWUD, hydromorphone prescriptions could be used alongside opioid agonist therapy (OAT) to reduce withdrawal and cravings and improve adherence to OAT. However, some physicians were wary of prescribing hydromorphone due to the lack of evidence for this new approach. Our findings underscore the importance of providing YPWUD with a safe supply of the substances they are actively using alongside a continuum of substance use treatment and care, and the need for both medical and community-based safe and safer supply models.

Diagnostic yield and repeat biopsies in rectal and nonrectal colorectal adenocarcinoma: Are we hedging on rectal biopsies?

Patients with rectal cancer undergo more repeat biopsies compared to those with nonrectal colon cancer prior to management. We investigated the factors driving the higher frequency of repeat biopsies in patients with rectal cancer. We compared clinicopathologic features of diagnostic and nondiagnostic (in regard to invasion) rectal (n = 64) and colonic (n = 57) biopsies from colorectal cancer patients and characterized corresponding resections. Despite similar diagnostic yield, repeat biopsy was more common in rectal carcinoma, especially in patients receiving neoadjuvant therapy (p < 0.05). The presence of desmoplasia (odds ratio 12.9, p < 0.05) was a strong predictor of making a diagnosis of invasion in both rectal and nonrectal colon cancer biopsies. Diagnostic biopsies had more desmoplasia, intramucosal carcinoma component and marked inflammation, and less low-grade dysplasia component (p < 0.05). Diagnostic yield of biopsy was higher for tumors with high-grade tumor budding, mucosal involvement by high-grade dysplasia/intramucosal carcinoma without low-grade dysplasia and diffuse surface desmoplasia irrespective of tumor location. Sample size, amount of benign tissue, appearance, and T stage did not affect diagnostic yield. Repeat biopsy of rectal cancer is primarily driven by management implications. Diagnostic yield in colorectal cancer biopsies is multifactorial and is not due to differing pathologists' diagnostic approach per tumor site. For rectal tumors, a multidisciplinary strategic approach is warranted to avoid repeat biopsy when unnecessary.

PSMA Immunohistochemistry in Hepatic Neoplasms: A Promising Diagnostic Marker With Potential Theranostic Applications

Accurate classification of well-differentiated hepatocellular neoplasms can be challenging especially in core biopsies. Prostate-specific membrane antigen (PSMA) has been shown to highlight tumor-associated neovasculature in many nonprostatic solid tumors including hepatocellular carcinoma (HCC). Archived 164 hepatectomies and explants with 68 HCCs, 31 hepatocellular adenoma (HA), 24 dysplastic nodules (DN), and 42 metastases were retrieved, and pathologic parameters were evaluated. Sensitivity, specificity, accuracy, positive, and negative predictive values for correct diagnosis of HCC were calculated for PSMA and CD34 immunostains in tissue sections and HCC tissue microarrays. PSMA positivity was defined as capillarized sinusoidal/tumor-associated vessel staining involving ≥5% of the tumor area. In all, 55/68 (80.9%) HCC and 37/42 (88.1%) of liver metastasis were PSMA positive. PSMA was negative in HA, DN, and background liver (100% specificity). CD34 had a 98.5% sensitivity but a 65.5% specificity in identifying HCC. PSMA sensitivity remained high in the HCC tissue microarray (89.7%). PSMA was more accurate than CD34 (95.5% vs. 69.7%) in distinguishing grade 1 HCC from HA and high-grade DN while retaining high sensitivity (80%). The degree of PSMA positivity in HCC was greater in older, male, and human immunodeficiency virus patients ( P <0.05). No associations were found between PSMA staining and other tumor parameters ( P >0.05). PSMA is a marker of neoangiogenesis with increased expression in both primary and metastatic hepatic malignancies. Neovascular PSMA expression is more specific and accurate than CD34 for differentiating HCC from benign and precursor hepatic lesions. Diagnostic and therapeutic utility of PSMA radioligands in malignant liver neoplasms warrant further clinical investigations.

Self-injecting non-prescribed substances into vascular access devices: a case study of one health system's ongoing journey from clinical concern to practice and policy response

BACKGROUND

Overdose-associated deaths and morbidity related to substance use is a global public health emergency with devastating social and economic costs. Complications of substance use are most pronounced among people who inject drugs (PWID), particularly infections, resulting in increased risk of hospitalization. PWID often require intravenous access for medical treatments such as antibiotics; however, vascular access may be limited due to the impacts of long-term self-venipuncture. While vascular access devices including peripherally inserted central catheters (PICCs) allow reliable and sustained routes of administration for indicated therapies, the use of PICCs among PWID presents unique challenges. The incidence and risks associated with self-injecting non-prescribed substances into vascular access devices (SIVAD) is one such concern for which there is limited evidence and absence of formal practice guidance.

CASE PRESENTATION

We report the experience of a multidisciplinary team at a health organization in Vancouver, Canada, working to characterize the incidence, patient and healthcare provider perspectives, and overall impact of SIVAD. The case study of SIVAD begins with a patient's perspective, including patient rationale for SIVAD, understanding of risks and the varying responses given by healthcare providers following disclosure of SIVAD. Using the limited literature available on the subject, we summarize the intersection of SIVAD and substance use and outline known and anticipated health risks. The case study is further contextualized by experience from a Vancouver in-hospital Overdose Prevention Site (OPS), where 37% of all individual visits involve SIVAD. The case study concludes by describing the systematic process by which local clinical guidance for SIVAD harm reduction was developed with stakeholder engagement, medical ethics consultation, expert consensus guideline development and implementation with staff education and planned research evaluation.

CONCLUSION

SIVAD is encountered with enough frequency in an urban healthcare setting in Vancouver, Canada, to warrant an organizational approach. This case study aims to enhance appreciation of SIVAD as a common and complex clinical issue with anticipated health risks. The authors conclude that using a harm reduction lens for SIVAD policy and research can provide benefit to clinicians and patients by offering a clear and a consistent healthcare response to this common issue.

Primary care embedded within permanent supportive housing for people who use substances: A qualitative study examining healthcare access in Vancouver, Canada

Marginally housed people who use drugs and alcohol (PWUD/A) face barriers in accessing healthcare services, which may be improved by providing healthcare in housing settings. This case study examines the experiences of healthcare access amongst PWUD/A who live in a permanent supportive housing model in Vancouver, Canada. This model has an embedded multidisciplinary clinic providing in-reach services. Thirty participants were recruited via posters placed throughout the building and semi-structured qualitative interviews were conducted remotely. Interviews were conducted with participants who accessed onsite care regularly (n = 15) and those who do not (n = 15). Data were analysed to identify both a priori and emerging themes. Participants who accessed the onsite clinic reported benefiting from stigma-free care. Close proximity and convenience of drop-in appointments enabled participants to engage with healthcare services more consistently, though hours of operation and privacy concerns were barriers for others. Participants who did not use the onsite clinic highlighted the importance of continuity of care with their pre-existing primary care team, particularly if their clinic was in close geographic proximity. However, they also described utilising these services for urgent health needs or as an occasional alternative source of care. Shared perspectives across all participants emphasised the importance of low-barrier services, including medication delivery, convenience and positive therapeutic relationships. Our findings suggest that embedding access to primary care within supportive housing benefits PWUD/A who have previously encountered barriers to healthcare access. This model could be implemented to prevent utilisation of acute healthcare resources and improve health outcomes amongst PWUD/A.

"COVID just kind of opened a can of whoop-ass": The rapid growth of safer supply prescribing during the pandemic documented through an environmental scan of addiction and harm reduction services in Canada

OBJECTIVES

In the context of the ongoing overdose crisis, a stark increase in toxic drug deaths from the unregulated street supply accompanied the onset of the COVID-19 pandemic. Injectable opioid agonist treatment (iOAT - hydromorphone or medical-grade heroin), tablet-based iOAT (TiOAT), and safer supply prescribing are emerging interventions used to address this crisis in Canada. Given rapid clinical guidance and policy change to enable their local adoption, our objectives were to describe the state of these interventions before the pandemic, and to document and explain changes in implementation during the early pandemic response (March-May 2020).

METHODS

Surveys and interviews with healthcare providers comprised this mixed methods national environmental scan of iOAT, TiOAT, and safer supply across Canada at two time points. Quantitative data were summarized using descriptive statistics; interview data were coded and analyzed thematically.

RESULTS

103 sites in 6 Canadian provinces included 19 iOAT, 3 TiOAT and 21 safer supply sites on March 1, 2020; 60 new safer supply sites by May 1 represented a 285% increase. Most common substances were opioids, available at all sites; most common settings were addiction treatment programs and primary care clinics, and onsite pharmacies models. 79% of safer supply services were unfunded. Diversity in service delivery models demonstrated broad adaptability. Qualitative data reinforced the COVID-19 pandemic as the driving force behind scale-up.

DISCUSSION

Data confirmed the capacity for rapid scale-up of flexible, community-based safer supply prescribing during dual public health emergencies. Geographical, client demographic, and funding gaps highlight the need to target barriers to implementation, service delivery and sustainability.

Inflammation and tissue remodeling contribute to fibrogenesis in stricturing Crohn’s disease: image processing and analysis study

Background

Inflammation and structural remodeling may contribute to fibrogenesis in Crohn’s disease (CD). We quantified the immunoexpression of calretinin, CD34, and calprotectin as a surrogate for mucosal innervation, telocytes (interstitial cells playing a role in networking), and inflammation, respectively, and correlated them with bowel alterations in stricturing CD.

Methods

Primary resection specimens for ileal CD (n = 44, 31 stricturing CD, 13 inflammatory CD) were identified. Left-sided ulcerative colitis and trauma cases were used as controls. Proximal and distal margin and middle (diseased) sections were stained for calretinin, CD34, and calprotectin. Microscopic images were captured from the mucosa (calretinin), submucosa (calprotectin), and myenteric plexus (CD34), and the immunostaining was quantified using image processing and analysis. Bowel thickness at the corresponding sections were measured and correlated with the amount of immunoexpression.

Results

A total of 2,037 images were analyzed. In stricturing CD, submucosal alteration/thickening at the stricture site correlated with calprotectin staining and inversely correlated with calretinin staining at the proximal margin. Muscularis propria alteration/thickening at the stricture site correlated with mucosal calretinin staining at the proximal margin. Submucosal alteration/thickening at the proximal margin correlated with calretinin and CD34 staining at the proximal margin and inversely correlated with CD34 staining at the stricture site. Calretinin immunostaining at the distal margin was significantly higher in stricturing CD than the controls.

Conclusions

Inflammation and tissue remodeling appear to contribute to fibrogenesis in stricturing CD. Increased mucosal calretinin immunostaining distal to the diseased segment could be helpful in diagnosing CD in the right clinical context.

Histologic Findings and Tissue B-Cell Depletion in Endoscopic Mucosal Biopsy Specimens of the Gastrointestinal Tract After Treatment With Rituximab

OBJECTIVES

Rituximab (RTX) is associated with variable adverse gastrointestinal (GI) events. However, the histologic correlate in affected patients is not well defined.

METHODS

Patients (n = 93) who had received RTX and undergone endoscopic biopsies were identified. CD20 and PAX5 immunostains were performed on biopsy specimens showing inflammatory pathology (group A, 36 patients) and 35 of 57 noninflammatory biopsies (group B) that were taken within 1 year from the last RTX infusion. Histologic findings were correlated with tissue B-cell depletion (CD20/PAX5-/-).

RESULTS

B cells were depleted in 12 (33%) of 36 group A biopsy specimens. After excluding biopsies taken more than 1 year from the last RTX infusion, the frequencies of tissue B-cell depletion were similar between group A (12/26; 46.2%) and group B (17/35; 48.6%) (P > .05). Also, the frequencies of inflammatory pathology were not statistically different whether B cells were depleted or not (P > .05). In group A with tissue B-cell depletion (n = 12), causality was indicated in two (17%) cases showing lymphocytic colitis pattern of injury (LCPI).

CONCLUSIONS

In RTX-treated patients, tissue B-cell depletion does not appear to be the main cause of inflammatory pathology in the GI tract. A minor subset, however, develops histologic evidence of potential RTX-induced effect, notably in the form of LCPI.

Challenges with buprenorphine inductions in the context of the fentanyl overdose crisis: A case series

INTRODUCTION AND AIMS

North America is currently experiencing an epidemic of opioid overdose deaths, driven by the proliferation of fentanyl in the street drug market. Although buprenorphine/naloxone (BUP/NX) is an evidence-based, first-line opioid agonist for the management of opioid use disorder, a key challenge in its prescribing lies in the fact that it can precipitate opioid withdrawal during its initial induction process. At this time, there is minimal literature on the BUP/NX induction process in individuals who use illicit fentanyl regularly.

DESIGN, METHODS AND RESULTS

A case series from a Vancouver, Canada addiction medicine clinic of three fentanyl-exposed patients who experienced unexpected, precipitated withdrawal when initiating BUP/NX.

DISCUSSION AND CONCLUSION

These cases describe incidents of precipitated opioid withdrawal occurring after unusually long periods of fentanyl abstention. Although fentanyl is experienced as a short-acting opioid, the drug persists much longer in the body's peripheral tissues. Here, we highlight the new challenges fentanyl may pose to current BUP/NX induction strategies, and explore the possibility of a long-acting pharmacokinetic effect of fentanyl in the setting of repeated illicit use.

Inability to contact opioid agonist therapy prescribers during the COVID-19 pandemic in a Canadian setting: a cross-sectional analysis among people on opioid agonist therapy

BACKGROUND

The COVID-19 pandemic and consequent public health response may have undermined key responses to the protracted drug poisoning crisis, including reduced access to opioid agonist therapy (OAT) among people with opioid use disorder. Our study objectives were to estimate the prevalence of and identify factors associated with inability to contact OAT prescribers when in need among people on OAT in a Canadian setting during the dual public health crises.

METHODS

Survey data were collected from three prospective cohort studies of community-recruited people who use drugs between July and November 2020, in Vancouver, Canada. A multivariable logistic regression analysis was used to identify potential factors associated with inability to contact OAT prescribers among patients who accessed OAT in the past 6 months.

RESULTS

Among 448 respondents who reported accessing OAT in the past 6 months, including 231 (54.9%) men, 85 (19.0%) reported having been unable to contact OAT prescribers when needed, whereas 268 (59.8%) reported being able to talk to their prescriber when needed, and 95 (21.2%) reported that they did not want to talk to their medication prescriber in the previous 6 months. Among those who reported inability to contact prescribers, 45 (53.6%) reported that their overall ability to contact prescribers decreased since the start of the pandemic. In multivariable analyses, factors independently associated with inability to talk to OAT prescribers included: chronic pain (Adjusted Odds Ratio [AOR] = 1.82; 95% Confidence Interval [CI] 1.02, 3.27), moderate to severe symptoms of depression or anxiety (AOR = 4.74; 95% CI 2.30, 9.76), inability to access health/social services (AOR = 2.66; 95% CI 1.41, 5.02), and inability to self-isolate or socially distance most or all of the time (AOR = 2.13; 95% CI 1.10, 4.14).

CONCLUSIONS

Overall, approximately one fifth of the sample reported inability to contact their OAT prescribers when needed, and those people were more likely to have co-occurring vulnerabilities (i.e., co-morbidities, inability to access health/social services) and higher vulnerability to COVID-19. Interventions are needed to ensure optimal access to OAT and mitigate the deepening health inequities resulting from the COVID-19 pandemic and the escalating drug poisoning crisis.

Inability to access primary care clinics among people who inject drugs in a Canadian health care setting

OBJECTIVE

To examine the prevalence and correlation of self-reported inability to access community primary care clinics among people who inject drugs (PWID).

DESIGN

Self-report questionnaire data.

SETTING

Vancouver, BC.

PARTICIPANTS

Data were derived from 3 prospective cohort studies of PWID between 2013 and 2016.

MAIN OUTCOME MEASURES

Multivariable generalized estimating equations were used to determine prevalence of and reasons for self-reported inability to access primary care, as well as factors associated with inability to access care.

RESULTS

Of 1396 eligible participants, including 525 (37.6%) women, 209 (15.0%) persons were unable to access a primary care clinic at some point during the study period. In the multivariable analysis, factors independently associated with inability to access clinics included ever being diagnosed with a mental health disorder (adjusted odds ratio [AOR] = 1.63, 95% CI 1.14 to 2.35), dealing drugs (AOR = 1.60, 95% CI 1.15 to 2.22), using emergency services (AOR = 1.51, 95% CI 1.13 to 2.02), being female (AOR = 1.49, 95% CI 1.08 to 2.08), and testing positive for HIV (AOR = 0.47, 95% CI 0.30 to 0.72) (for all factors, P < .05).

CONCLUSION

Specific exposures were linked to challenges in accessing primary care among the sample of PWID, even in a publicly funded health care setting. Notably, models designed for care of people with HIV appear to increase access to primary care among PWID. Further research is needed to determine how to effectively treat accompanying mental illness, how to provide women-centred services, and how to connect people with primary care who would likely otherwise go to the emergency department.

Changes in drug use behaviors coinciding with the emergence of illicit fentanyl among people who use drugs in Vancouver, Canada

Background: With the emergence of illicitly-manufactured fentanyl, drug overdose deaths have risen in unprecedented numbers. In this context, there is an urgent need to characterize potential changes in drug use behaviors among people who use drugs (PWUD). Objective: To examine changes in drug use behaviors following the emergence of illicit fentanyl among people who use drugs (PWUD). Methods: Data for this cross-sectional analysis was derived from three prospective cohorts of PWUD between December 2016 and May 2017 in Vancouver, Canada. Multivariable logistic regression was used to determine factors associated with self-reported behavior changes (binary variable "yes" or "no") following the emergence of illicit fentanyl. Results: Among 999 participants [363 (36.3%) females], 388 (38.8%) reported some behavior change. The remaining 611 (61.2%) reported no change in behavior; 240 (39.3%) of these individuals had recently been exposed to fentanyl. In multivariable analyses, factors independently associated with behavior change included recent non-fatal overdose (Adjusted Odds Ratio [AOR] = 2.28), active injection drug use (AOR = 1.96), being on opioid agonist therapy (AOR = 1.80), and urine drug screen positive for fentanyl (AOR = 1.45), (all p < .05). Conclusion: The majority of PWUD in our sample did not change their drug use behavior despite a high prevalence of fentanyl exposure, indicating a need for targeted behavior change messaging and overdose prevention efforts such as naloxone and addiction treatment for this sub-population of PWUD. Further, the high fentanyl exposure observed in our sample suggests a need to address upstream structural factors shaping the overdose risk in addition to individual behavioral change.

Use of a novel prescribing approach for the treatment of opioid use disorder: Buprenorphine/naloxone micro-dosing - a case series

INTRODUCTION AND AIMS

Buprenorphine/naloxone is an evidence-based treatment for opioid use disorder, but an identified limitation is the period of required opioid abstinence prior to induction on the medication. 'Micro-dosing', or using incrementally increasing doses of buprenorphine/naloxone over time, may be a way to overcome this challenge as it can be done in parallel with the ongoing use of other opioids (either illicit or prescribed).

DESIGN AND METHODS

A retrospective case series (January to December 2018) was completed of seven participants who underwent buprenorphine/naloxone induction using micro-dosing at two outpatient addiction clinics in Vancouver, Canada.

RESULTS

Seven participants completed a 7-day buprenorphine/naloxone micro-dosing protocol. Prior to and during the induction, one participant was prescribed methadone, three were prescribed slow release oral morphine and three used only illicit fentanyl. Participants were prescribed sublingual buprenorphine/naloxone: 0.5 mg once daily (day 1), 0.5 mg twice daily (BID; day 2), 1 mg BID (day 3), 2 mg BID (day 4), 3 mg BID (day 5), 4 mg BID (day 6) and 12 mg once daily (day 7). On day 7, all prescribed or illicit full opioid agonists were discontinued. Buprenorphine/naloxone was subsequently titrated to a daily dose of between 12 and 32 mg. All patients reported success with buprenorphine/naloxone induction with no precipitated withdrawal.

DISCUSSION AND CONCLUSIONS

Buprenorphine/naloxone micro-dosing may offer a promising alternative approach for successful induction for individuals with opioid use disorder who desire treatment with buprenorphine/naloxone, and further research to determine effectiveness is warranted.

Slow release oral morphine versus methadone for opioid use disorder in the fentanyl era (pRESTO): Protocol for a non-inferiority randomized clinical trial

BACKGROUND

North America is facing an unprecedented public health crisis of opioid-related morbidity and mortality, increasingly as a result of the introduction of illicitly manufactured fentanyl into the street drug market. Although the treatment of opioid use disorder (OUD) is a key element in the response to the opioid overdose epidemic, currently available pharmacotherapies (e.g., methadone, buprenorphine) may not be acceptable to or effective in all patients. Available evidence suggests that slow-release oral morphine (SROM) has similar efficacy rates as methadone with respect to promoting abstinence, and with improvements in a number of patient-reported outcomes among persons using heroin. However, little is known about the relative effectiveness and acceptability of SROM compared to methadone in the context of fentanyl use. This study aims to address this research gap.

METHODS

pRESTO is a 24-week, open-label, two arm, non-inferiority, randomized controlled trial comparing SROM versus methadone for the treatment of OUD. Participants will be 298 clinically stable, non-pregnant adults with OUD, recruited from outpatient clinics in Vancouver, Canada, where the majority of the illicit opioids are contaminated with fentanyl. The primary outcome is suppression of illicit opioid use, measured by bi-weekly urine drug screens. Secondary outcomes include: treatment retention, medication safety, overdose events, treatment satisfaction, psychological functioning, changes in drug-related problems, changes in quality of life, opioid cravings, other substance use, and cost-effectiveness.

DISCUSSION

pRESTO will be among the first studies to evaluate treatment options for individuals primarily using synthetic street opioids, providing important evidence to guide treatment strategies for this population.

Transitioning a patient from injectable opioid agonist therapy to sublingual buprenorphine/naloxone for the treatment of opioid use disorder using a microdosing approach

In the wake of North America's opioid crisis, access to evidence-based treatment for opioid use disorder (OUD) is of critical importance. While buprenorphine/naloxone and methadone are currently indicated as first-line medications for the treatment of OUD, there are a proportion of individuals who do not benefit from these therapies. Recent Canadian guidelines suggest the use of alternate therapies, including slow-release oral morphine or injectable opioid agonist therapy (iOAT) for individuals unsuccessful with either methadone or buprenorphine/naloxone. While the guidelines highlight the need to intensify OUD treatment as disease severity increases, equally important is the consideration for deintensification of treatment (eg, from iOAT to an oral opioid agonist treatment (OAT) option) following successful stabilisation. Literature addressing how best to accomplish this, however, is currently lacking. Accordingly, the case presented here describes a patient that successfully transitions from iOAT to oral buprenorphine/naloxone using a novel induction approach termed microdosing.

Trajectories of retention in opioid agonist therapy in a Canadian setting

BACKGROUND

Long-term engagement in opioid agonist therapy (OAT) has been consistently associated with reduced risk for morbidity and mortality in people with opioid use disorder (OUD). However, the dynamic nature of engagement/disengagement in OUD care for over time is poorly captured by traditional metrics. We characterized long-term longitudinal trajectories of engagement in OAT in Vancouver, Canada, between 2005 and 2018.

METHODS

Data were derived from two community-recruited prospective cohorts of people who use drugs. Retention in OAT was defined as self-reported enrolment in OAT for two consecutive follow-up periods (an approximately six-month retention interval). We used latent class growth analysis to identify OAT engagement trajectories during the first five years after OAT initiation and multivariable logistic regression to evaluate predictors of trajectory group membership.

RESULTS

We identified four OAT retention trajectories among 438 OAT initiators: "consistently high" (36%), "consistently low" (23%), "increasing" (23%), and "decreasing" (15%). Employment was a significant cross-cutting predictor of membership of all sub-optimal OAT engagement patterns compared to consistently high trajectories. We also found that initiating OAT after 2014 (when regulatory changes to the provincial OAT program were introduced) was associated with the "consistently low" engagement group relative to others.

CONCLUSIONS

We identified four distinct OAT engagement trajectories in Vancouver, Canada, with employment being a common predictor of sub-optimal care trajectories, suggesting the need to explore alternative OAT models to address employment-related barriers. Care trajectory analysis could help inform tailored interventions to specific populations of people with OUD at specific time points to improve engagement in OAT, and decrease opioid-related morbidity and mortality.

Initiation of injectable opioid agonist treatment in hospital: A case report

Uncontrolled opioid withdrawal and pain often drive inpatients with opioid use disorder to leave hospital against medical advice, resulting in suboptimal medical and addiction treatment. When oral opioid agonist treatments such as methadone and buprenorphine/naloxone fail for management of craving and withdrawal, injectable opioid agonist treatment may serve to retain patients in care and link them to addiction services. We describe the case of a 47-year-old man with a severe, active opioid use disorder and daily use of illicitly manufactured fentanyl, who was re-admitted to hospital for post-operative management after leaving against medical advice due to uncontrolled opioid withdrawal. Intravenous hydromorphone was used to retain him in care, allowing for completion of his antibiotics and enrolment in ongoing community injectable opioid agonist treatment.

Fentanyl assisted treatment: a possible role in the opioid overdose epidemic?

Background

The current opioid overdose epidemic affecting communities across North America is increasingly driven by illicitly manufactured fentanyl and its related analogues. A variety of public health interventions have been implemented and scaled up, including opioid agonist treatments (OAT). While these treatments are successful for many individuals, they have a variety of limitations. It is critical to trial alternative treatments if conventional opioid agonist treatment options are not successful for a proportion of patients who use illicit fentanyl.

Main body

Prescription fentanyl has been widely used for pain management. The use of transdermal fentanyl, specifically, which provides long acting and stable drug levels post-titration over several days, should be explored as an opioid agonist treatment option. The use of transdermal fentanyl for patients who use illicit fentanyl is currently being piloted in Vancouver, Canada. To address potential diversion, the patch is signed, dated, and a film dressing is applied to mitigate tampering. Evaluation outcomes are still pending, but there have been no adverse outcomes thus far and clinical improvements have been noted for many patients. This exploratory therapeutic approach should be considered across multiple settings and rigorously evaluated.

Conclusions

There are known limitations to existing OAT options and there is a need to urgently evaluate alternative strategies for patients who are using illicit fentanyl not successfully treated with conventional OAT. Many patients may be attracted to, and retained in, fentanyl assisted treatment. This may be another strategy for certain patients to prevent harms caused by illicit fentanyl use, including overdose and death.

Supervised injectable opioid agonist therapy in a supported housing setting for the treatment of severe opioid use disorder

Currently, North America is facing a national opioid overdose crisis. Opioid use disorder (OUD) is a chronic, relapsing condition requiring varying intensities of treatment. Injectable opioid agonist therapy (iOAT) is an effective, high-intensity treatment option for people who are unsuccessful on conventional oral opioid agonist treatments (eg, methadone, buprenorphine). This case highlights the effectiveness of the provision of iOAT in a low-barrier setting. More specifically, we discuss a patient with severe OUD and untreated HIV infection, who was disengaged from medical care and, consequently, was prescribed iOAT in a supportive housing setting.

Factors associated with discontinuation of methadone maintenance therapy (MMT) among persons who use alcohol in Vancouver, Canada

BACKGROUND

We sought to examine the factors associated with discontinuation of MMT among persons on methadone who use alcohol.

METHODS

We evaluated the impact of drug-related and other factors on discontinuation of MMT among persons enrolled in MMT and who reported any use of alcohol versus those who were enrolled in two community-recruited prospective cohorts of people who use illicit drugs (PWUD). Extended Cox models with time-dependent variables identified factors independently associated with time to first MMT discontinuation.

RESULTS

Between December 2005 and 2015, 823 individuals on MMT who also reported using alcohol at least once were included in these analyses. During the study period, 391 (47.5%) discontinued methadone. Daily heroin injection (Adjusted Hazard Ratio [AHR] = 2.67, 95% Confidence Interval [CI]: 2.10-3.40) and homelessness (AHR = 1.42, 95% CI: 1.10-1.83) were positively associated with MMT discontinuation, whereas receiving other concurrent addiction treatment in addition to MMT (AHR = 0.07, 95% CI: 0.05-0.08), as well as >60 mg methadone dose (AHR = 0.48, 95% CI: 0.39-0.60), Hepatitis C virus seropositivity (AHR = 0.65, 95% CI: 0.47-0.90), and HIV seropositivity (AHR = 0.72, 95% CI: 0.57-0.91) were negatively associated with MMT discontinuation. Any/heavy alcohol use was not independently associated with MMT discontinuation.

CONCLUSIONS

This study reinforces the known risks of continued heroin injection and homelessness for MMT discontinuation among individuals who also consume alcohol and highlights the protective effect of both MMT dose and receipt of concurrent addiction treatment.

Chlorpyrifos chronic toxicity in broilers and effect of vitamin C

An experiment was conducted to study chlorpyrifos chronic toxicity in broilers and the protective effect of vitamin C. Oral administration of 0.8 mg/kg body weight (bw) (1/50 LD50) chlorpyrifos (Radar�), produced mild diarrhea and gross lesions comprised of paleness, flaccid consistency and slightly enlargement of liver. Histopathologically, chlorpyrifos produced degenerative changes in various organs. Oral administration of 100 mg/kg bw vitamin C partially ameliorated the degenerative changes in kidney and heart. There was insignificant alteration in biochemical and haematological profiles. It is concluded that supplementation of vitamin C reduced the severity of lesions induced by chronic chlorpyrifos toxicity in broilers.

Endovascular repair of an aortic arch aneurysm using a branched-stent graft

INTRODUCTION

Aortic arch aneurysm repair continues to pose a formidable technical challenge in a patient population with significant co-morbidity.

REPORT

We present a successful endovascular repair of an 8.4 cm aortic arch aneurysm, in a 74 year old man, who's previous median sternotomy showed signs of delayed healing, precluding open repair.

DISCUSSION

Applied endovascular techniques obviated the need for aortic clamping, cardiac bypass, or hypothermic circulatory arrest, via an approach that was potentially infected.

Feasibility of continuous transthoracic cardiac imaging using a novel ultrasound transducer

BACKGROUND

The feasibility of hands-free transthoracic continuous ultrasonic cardiac imaging has not been demonstrated previously. We developed a 2.5-MHZ spherical transducer mounted in an external housing to permit steering in 360 degrees (CONTISON). The external housing was attached to the chest wall using an adhesive patch.

METHODS AND RESULTS

The transducer was placed in the third or fourth interspace at the left sternal border to permit imaging of the left ventricle (LV) in its short axis and attached to the chest wall. The transducer then was attached to an ultrasound machine. Ten normal subjects and 20 patients with previous myocardial infarction were studied. The following maneuvers were performed at the beginning of the study: (1) The patient was rotated from the supine position (0 degrees ) in 20 degrees increments to the left lateral decubitus position (90 degrees ). The echocardiogram was displayed continuously and was recorded on videotape (parasternal short-axis view) at 0 degrees, 20 degrees, 40 degrees, 60 degrees, 80 degrees, and 90 degrees. (2) The patient was returned to the supine position and an echocardiogram was obtained. The patient was then seated up 20 degrees, 40 degrees, 60 degrees, 80 degrees, and 90 degrees by using the controls on the bed. (3) The patient then was returned to the supine position and the echocardiogram was displayed continuously on the monitor. The echocardiogram was recorded every 15 minutes for a period of 4 hours. All segments of the LV were visualized in the supine position and during lateral rotation (0 degrees -90 degrees ). Thus, body position did not affect the image. All segments of the LV were visualized during sitting up (0 degrees -90 degrees ), and all segments were visualized during the 4 hours of imaging. The patients were able to move around without distortion of the image.

CONCLUSION

The CONTISON transducer permitted continuous imaging of LV wall motion. Body position did not affect interpretation of wall motion. This device has potential applicability in monitoring LV function in the intensive care setting.

Role of nitric oxide and cGMP in human septic serum-induced depression of cardiac myocyte contractility

Previous studies have demonstrated the existence of a circulating myocardial depressant substance during human septic shock. We have recently identified this substance as a synergistic combination of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta). This study utilized an in vitro cardiac myocyte assay to evaluate the potential mechanistic role of nitric oxide (NO) and cGMP in depression of myocyte contractility induced by TNF-alpha, IL-1beta, TNF-alpha + IL-1beta (at low concentrations), and human septic shock serum (HSS). TNF-alpha, IL-1beta, TNF-alpha + IL-1beta, and each of 5 sera from patients with acute septic shock caused depression of both maximum extent and peak velocity of cardiac myocyte shortening and an increase in intracellular cGMP concentration during 30 min of exposure (minimum P < 0.01). NO synthetase (NOS) and guanylate cyclase inhibitors such as N-methyl-L-arginine (L-NMA) and methylene blue prevented these effects; an excess of L-arginine with L-NMA restored them (minimum P < 0.01). In contrast, D-arginine failed to reestablish cytokine-induced myocyte depression and cGMP accumulation prevented by L-NMA. Exposure of myocytes to TNF-alpha, IL-1beta, or TNF-alpha + IL-1beta produced a concentration-dependent increase in intracellular cGMP that paralleled the depression of cardiac myocyte contractility (minimum P < 0.001). In addition, TNF-alpha, IL-1beta, TNF-alpha + IL-1beta, or HSS application to cardiac myocytes resulted in increased NO gas generation, which was inhibited by L-NMA (minimum P < 0.01). Furthermore, unstimulated cardiac myocytes were shown to harbor constitutive but not inducible NOS activity. These data suggest that the sequential generation of NO by a constitutive NOS and cGMP by guanylate cyclase represents an important mechanism of cardiac myocyte depression by TNF-alpha, IL-1beta, TNF-alpha + IL-1beta, and the myocardial depressant substance(s) of septic shock.

Comparison of MPEG digital video with super VHS tape for diagnostic echocardiographic readings

BACKGROUND

Digital recording of echocardiographic studies is on the clinical horizon. However, full digital capture of complete echocardiographic studies in traditional video format is impractical, given current storage capacity and network bandwidth. To overcome these constraints, we evaluated the diagnostic image quality of digital video by using MPEG (Motion Picture Experts Group) compression.

METHODS AND RESULTS

Fifty-eight complete, consecutive studies were recorded simultaneously with the use of MPEG-1 and sVHS videotape. Each matched MPEG and sVHS study pair was reviewed by two from a total of six readers, and findings were recorded with the use of a detailed, computerized reporting tool. Intrareader and interreader discrepancies were characterized as major or minor and analyzed in total and for specific subgroups of findings (left and right ventricular parameters, valvular insufficiency, and left ventricular regional wall motion). Intrareader discrepancies were reviewed by a consensus panel for agreement with either MPEG or sVHS findings. There was an exact concordance between MPEG and sVHS readings in 83% of findings. The majority of discrepancies were minor, with major discrepancies in only 2.7% of findings. There was no difference in the rate of consensus panel agreement with MPEG or sVHS for instances of intrareader discrepancy, either in total or for any subgroup of findings. Interreader discrepancy rates were nearly identical for both MPEG and sVHS.

CONCLUSIONS

MPEG-1 digital video is equivalent to sVHS videotape for diagnostic echocardiography. MPEG increases the range of practical options for digital echocardiography and offers, for the first time, the advantages of digital recording in a familiar video format.