Opioid withdrawal management in the fentanyl era

Fentanyl, carfentanil and other fentanyl analogues in Canada's illicit opioid supply: A cross-sectional study

Background

Despite the increase in fentanyl-involved overdose deaths in Canada, there have been no national-level studies evaluating the proportion of illicit opioids containing fentanyl or fentanyl analogues in Canada.

Methods

This cross-sectional exploratory study characterized trends in fentanyl, carfentanil and other fentanyl analogues within opioids seized by law enforcement agencies in Canada from 2012 to 2022 and submitted to the Health Canada Drug Analysis Service (DAS). Analyses were stratified by province/region. Mann-Kandell tests were used to test for trends.

Results

A total of 157,616 samples containing any opioid ("opioid-containing samples") were submitted to the DAS from Canadian provinces between 2012 and 2022, of which 81,165 (51.5%) contained fentanyl or a fentanyl analogue. The percentage of opioid-containing samples that were positive for fentanyl or a fentanyl analogue increased from 3.0% (95% CI: 2.6-3.4%) in 2012-68.3% (67.7-68.9%) in 2022 (p < 0.001 for trend). The percentage of opioid-containing samples that were positive for fentanyl or a fentanyl analogue increased between 2012 and 2022 in all regions. In 2022, the percentage of samples containing fentanyl or an analogue followed an east-to-west gradient: 15.8% (13.3-18.6%) of samples in Atlantic Canada and 84.7% (83.6-85.7%) in British Columbia. Carfentanil was present in 4.9% (4.6-5.2%) of opioid-containing samples in Canada in 2022 and 19.7% (18.3-21.2%) of opioid-containing samples in Alberta.

Conclusions

The illicit opioid supply in Canada increasingly contains toxic synthetic opioids. As of 2022, important regional differences existed in the illicit opioid supply in Canada.

Establishing a research agenda for the study and assessment of opioid withdrawal

The opioid crisis is an international public health concern. Treatments for opioid use disorder centre largely on the management of opioid withdrawal, an aversive collection of signs and symptoms that contribute to opioid use disorder. Whereas in the past 50 years more than 90 medications have been developed for depression, only five medications have been developed for opioid use disorder during this period. We posit that underinvestment has occurred in part due to an underdeveloped understanding of opioid withdrawal syndrome. This Personal View summarises substantial gaps in our understanding of opioid withdrawal that are likely to continue to limit major advancements in its treatment. There is no firm consensus in the field as to how withdrawal should be precisely defined; 10-550 symptoms of withdrawal can be measured on 18 scales. The imprecise understanding of withdrawal is likely to result in overestimating or underestimating the severity of an individual's withdrawal syndrome or potential therapeutic effects of different candidate medications. The severity of the opioid crisis is not remitting, and an international research agenda for the study and assessment of opioid withdrawal is necessary to support transformational changes in withdrawal management and treatment of opioid use disorder. Nine actionable targets are delineated here: develop a consensus definition of opioid withdrawal; understand withdrawal symptomatology after exposure to different opioids (particularly fentanyl); understand precipitated opioid withdrawal; understand how co-exposure of other drugs (eg, xylazine and stimulants) influences withdrawal expression; examine individual variation in withdrawal phenotypes; precisely characterise the protracted withdrawal syndrome; identify biomarkers of opioid withdrawal severity; identify predictors of opioid withdrawal severity; and understand which symptoms are most closely associated with treatment attrition or relapse. The US Food and Drug Administration recently established a formal indication for opioid withdrawal that has invigorated interest in drug development for opioid withdrawal management. Action is now needed to support these interests and help industry identify new classes of medications so that real change can be achieved for people with opioid use disorder.

High-Dose Buprenorphine Initiation: A Scoping Review

OBJECTIVE

The aim of the study is to review and synthesize the literature on high-dose buprenorphine initiation (>12-mg total dose on day of initiation).

METHODS

A scoping review of literature about high-dose buprenorphine initiation was conducted. MEDLINE, Embase, PsycINFO, and Cochrane Central were searched. Randomized controlled trials, prospective and retrospective cohort studies, and case studies/reports published in English before February 13, 2023, were included.

RESULTS

Fifteen studies reporting outcomes from 580 high-dose buprenorphine initiations were included. Eight studies were in inpatient settings, 3 in emergency departments, 3 in outpatient settings, and 1 in a first-responder setting. Four studies reported high-dose initiations among individuals exposed to fentanyl. There were no reported events of fatal or nonfatal overdose or respiratory depression, although adverse event reporting was inconsistent in published reports. The most reported side effects with high-dose buprenorphine initiation were nausea or vomiting (n = 17) and precipitated withdrawal (n = 7). The most serious reported adverse event was hypotension requiring oral hydration (n = 2). Most studies reported improvements in subjective or objective withdrawal symptoms. The duration of follow-up ranged from none to 8 months.

CONCLUSIONS

High-dose buprenorphine initiation has not been associated with reported cases of overdose or respiratory depression. However, the current literature about high-dose buprenorphine is limited by inconsistent side effect reporting, limited power to detect rare safety events such as respiratory depression, limited follow-up data, and few comparison studies between high-dose and regular initiation protocols. Further prospective data are needed to evaluate the safety and effectiveness of this initiation strategy.

Clinical characteristics and prognostic factors among hospitalized patients with substance use disorders: Findings from a retrospective cohort study of a Canadian inpatient addiction medicine service

INTRODUCTION

Inpatient addiction medicine services (AMS) were developed in response to the growing needs of hospitalized individuals with substance use disorders (SUDs). AMS aim to enable timely initiation of pharmacologic treatment, build hospital capacity to support patients who use substances, and facilitate transition to community services. As an emerging service being adopted in hospitals across North America, the model of care, populations served, substance use trends, and clinical trajectory has not been widely described. This work aims to characterize patients accessing care through the AMS, establishing predictors for clinical trajectories in hospital including patient-initiated discharge (PID) and hospital re-admission.

METHODS

Using a retrospective cohort design, we describe all patients seen by the AMS between 2018 and 2022 across four hospitals in Hamilton, Ontario. Patients seen by AMS were hospitalized and qualified for a SUD based on DSM-V criteria. The study used descriptive statistics to describe the cohort, where appropriate adjusted time-to-event survival models were constructed to identify predictors for hospital re-admission.

RESULTS

Patients seen by the AMS (n = 695) frequently lacked access to primary care (47.0 %) and less than half (44.3 %) were receiving community addiction services on admission. The majority met criteria for opioid use disorder (OUD), with injecting being the primary consumption route (54.8 %). Patients exhibited high acuity, with 34.2 % requiring critical care measures. Provision of OAT substantially increased to 77.9 % of patients (29 % on admission). PID occurred in 17.8 % of patients and was significantly associated with an admitting diagnosis of suicidal ideation, infection, heart failure, and distinct substance use profiles including methamphetamine, fentanyl, and heroin use (p < 0.05). PID conferred a 66 % increased risk for re-admission (Hazard-Ratio: 1.66; 95 % CI: 1.08, 2.54; p = 0.02).

CONCLUSION

Patients served by AMS primarily include individuals with OUD presenting with the associated medical complications and substantial deficits in the social determinants of health (e.g., high housing insecurity, poverty, and disability). PID occurs among 1 in 5 people and is associated with higher rates of re-admission. By identifying individuals at higher risk of adverse outcomes, these results provide an opportunity to improve outcomes in this high-risk, high-vulnerability population.

Association of Urine Fentanyl Concentration With Severity of Opioid Withdrawal Among Patients Presenting to the Emergency Department

BACKGROUND AND AIMS

Fentanyl is involved in most US drug overdose deaths and its use can complicate opioid withdrawal management. Clinical applications of quantitative urine fentanyl testing have not been demonstrated previously. The aim of this study was to determine whether urine fentanyl concentration is associated with severity of opioid withdrawal.

DESIGN

This is a retrospective cross-sectional study.

SETTING

This study was conducted in 3 emergency departments in an urban, academic health system from January 1, 2020, to December 31, 2021.

PARTICIPANTS

This study included patients with opioid use disorder, detectable urine fentanyl or norfentanyl, and Clinical Opiate Withdrawal Scale (COWS) recorded within 6 hours of urine drug testing.

MEASUREMENTS

The primary exposure was urine fentanyl concentration stratified as high (>400 ng/mL), medium (40-399 ng/mL), or low (<40 ng/mL). The primary outcome was opioid withdrawal severity measured with COWS within 6 hours before or after urine specimen collection. We used a generalized linear model with γ distribution and log-link function to estimate the adjusted association between COWS and the exposures.

FINDINGS

For the 1127 patients in our sample, the mean age (SD) was 40.0 (10.7), 384 (34.1%) identified as female, 332 (29.5%) reported their race/ethnicity as non-Hispanic Black, and 658 (58.4%) reported their race/ethnicity as non-Hispanic White. For patients with high urine fentanyl concentrations, the adjusted mean COWS (95% confidence interval) was 4.4 (3.9-4.8) compared with 5.5 (5.1-6.0) among those with medium and 7.7 (6.8-8.7) among those with low fentanyl concentrations.

CONCLUSIONS

Lower urine fentanyl concentration was associated with more severe opioid withdrawal, suggesting potential clinical applications for quantitative urine measurements in evolving approaches to fentanyl withdrawal management.

Safety and preliminary outcomes of short-acting opioid agonist treatment (sOAT) for hospitalized patients with opioid use disorder

BACKGROUND

Patients with opioid use disorder (OUD) frequently leave the hospital as patient directed discharges (PDDs) because of untreated withdrawal and pain. Short-acting opioids can complement methadone, buprenorphine, and non-opioid adjuvants for withdrawal and pain, however little evidence exists for this approach. We described the safety and preliminary outcomes of short-acting opioid agonist treatment (sOAT) for hospitalized patients with OUD at an academic hospital in Philadelphia, PA.

METHODS

From August 2021 to March 2022, a pharmacist guided implementation of a pilot sOAT protocol consisting of escalating doses of oxycodone or oral hydromorphone scheduled every four hours, intravenous hydromorphone as needed, and non-opioid adjuvants for withdrawal and pain. All patients were encouraged to start methadone or buprenorphine treatment for OUD. We abstracted data from the electronic health record into a secure platform. The primary outcome was safety: administration of naloxone, over-sedation, or a fall. Secondary outcomes were PDDs and respective length of stay (LOS), discharges on methadone or buprenorphine, and discharges with naloxone. We compared secondary outcomes to hospitalizations in the 12 months prior to the index hospitalization among the same cohort.

RESULTS

Of the 23 cases, 13 (56.5%) were female, 19 (82.6%) were 40 years or younger, and 22 (95.7%) identified as White. Twenty-one (91.3%) regularly injected opioids and four (17.3%) were enrolled in methadone or buprenorphine prior to hospitalization. sOAT was administered at median doses of 200-320 morphine milligram equivalents per 24-h period. Naloxone administration was documented once in the operating room, over-sedation was documented once after unsanctioned opioid use, and there were no falls. The PDD rate was 44% with median LOS 5 days (compared to PDD rate 69% with median LOS 3 days for prior admissions), 65% of sOAT cases were discharged on buprenorphine or methadone (compared to 33% for prior admissions), and 65% of sOAT cases were discharged with naloxone (compared to 19% for prior admissions).

CONCLUSIONS

Pilot implementation of sOAT was safe. Compared to prior admissions in the same cohort, the PDD rate was lower, LOS for PDDs was longer, and more patients were discharged on buprenorphine or methadone and with naloxone, however efficacy for these secondary outcomes remains to be established.