Evaluating Buprenorphine/Naloxone Microdosing vs. Standard Dosing in Emergency Departments

This is a multi-centre, open-label RCT at four Emergency Departments (EDs) in British Columbia and Alberta. The purpose of the current study is to compare the effectiveness of buprenorphine/naloxone microdosing and standard dosing take-home induction regimens at enabling patients to successfully complete the induction regimen, and at retaining patients on opioid agonist therapy. We will randomize our enrolled patients to receive take-home microdosing or standard dosing packages of buprenorphine/naloxone. For the microdosing arm, patients immediately start taking low doses that increase to effective levels without requiring them to go into withdrawal. We hypothesize that ED patients provided buprenorphine/naloxone microdosing packages will be more likely to successfully complete the induction period compare to patients provided standard dosing packages. We furthermore hypothesize that those provided microdosing will be more likely to be retained in opioid agonist therapy, and will experience lower overdose, mortality, and healthcare utilization subsequent to their ED visit.

Inclusion Criteria: We will include ED patients ≥18 years of age with opioid use disorder who are being discharged from the ED. We will define opioid use disorder as non-medical opioid use in the previous 30 days and a positive score for opioid dependency based on the validated Rapid Opioid Dependence Screen (RODS). All patients will also be assessed by the treating physician or degree of clinical opioid withdrawal, based on the clinical opiate withdrawal scale (COWS) score. Patients will be eligible for the take-home study interventions if they have a COWS score \12) * Admitted to hospital * Severe communication barriers that inhibit patients' understanding of study procedures and interventions * Are taking opioids for cancer or palliative-care related indications * Are deemed unsafe to approach by ED providers * Incarceration * Not a resident of the province in which they are seeking care (BC or Alberta) * Actively receiving OAT, defined as having filled a prescription for one of the following medications in the 5 days prior to ED presentation: buprenorphine/naloxone, methadone, sustained release morphine, injectable hydromorphone, injectable diacetylmorphine * Prior enrollment in the study * Known or suspected mechanical gastrointestinal obstruction (e.g., bowel obstruction or strictures) or any diseases/conditions that affect bowel transit (e.g., ileus of any type). * Suspected surgical abdomen (e.g., acute appendicitis or pancreatitis). * Severe respiratory insufficiency. * Severe CNS depression, increased cerebrospinal or intracranial pressure, and head injury. * Complicating patient factors that make home inductions from the ED unsafe and/or that require expert consultation for consideration of induction in an observed setting. These factors include: * Allergy to buprenorphine/naloxone * Severe respiratory or liver dysfunction * Concurrent withdrawal or intoxication from sedatives (e.g., alcohol, benzodiazepines) * Active prescription for sedative medications (e.g., benzodiazepines, opioids) * Use of monoamine oxidase inhibitors within the past 14 days * Concerns that the patient is unable to safely store medications * Pregnancy (we will obtain a point-of-care urine pregnancy test on all women of child-bearing age prior to enrollment)