Remarks:

• The quality of evidence for this recommendation was rated as high based on multiple systematic reviews demonstrating that OAT is effective in improving treatment retention and reducing unregulated opioid use and related morbidity and mortality
• This recommendation was rated as strong based on the quality of evidence supporting the efficacy and safety of OAT and guideline committee consensus.

Prescribers should work with each patient to determine which of the following opioid agonist treatment medications is most appropriate based on the patient’s circumstances, goals, and previous treatment experiences. 

• Buprenorphine/naloxone
• Methadone
• Slow-release oral morphine

Remarks:

• The guideline committee emphasizes the importance of a collaborative, patient-centred approach to treatment selection.
• However, this move away from ranking oral OAT medications is not intended to equate them in terms of safety and efficacy evidence. While available data generally supports SROM’s non-inferiority to other OAT options, further research is needed to comprehensively characterize SROM’s comparative risks and benefits. There is also an absence of data establishing the extent of SROM’s impact on opioid-related mortality. These facts are reflected in the “moderate” quality of evidence assigned to SROM for this recommendation.
• Clinicians should offer patients consultation on the risks and benefits of all three OAT medications prior to medication selections
  • Clinicians whose current scope of OAT prescribing is limited to buprenorphine/naloxone should provide information on all 3 medications and offer appropriate referrals to a prescriber of these medications if needed
• Individual factors to consider for treatment selection may include:
  • Initial presentation
  • Comorbidities that may be a contraindication for specific OAT options
  • Drug–drug interactions
  • Treatment preferences and goals
  • Lifestyle requirements (e.g., remote location or frequent travel indicate a preference for medications or formulations that allow more flexibility with dosing and carry protocols)
  • Previous experience with OAT
• In the absence of patient preference or other patient-specific factors that would favour other medications, buprenorphine/naloxone may be considered as the favourable option due to its superior safety profile.

Remarks:

• Available guidelines and clinical experience support the feasibility of transition between medications if indicated by patient preference or individual circumstances.
• For example, patients stable on other OAT medications may wish to transition to buprenorphine/naloxone for a range of reasons including:
  • Fewer side effects
  • Possibility for transition to the monthly extended-release buprenorphine formulation
  • Increased treatment flexibility
• Prior to conducting the transition, clinicians should discuss the risks of switching medication, such as the risk of withdrawal and cravings during the period of transition. The risks and benefits of transition between OAT medication should be weighed carefully for patients who are stable on their current medication. 
   

Remarks:

• This recommendation has been predominantly graded based on two clinical trials demonstrating extended-release buprenorphine’s effectiveness in treatment retention and reduction in unregulated opioid use.
• The extended-release formulation of buprenorphine is administered monthly via abdominal subcutaneous injection, which, according to observational findings, may be preferable for patients seeking to enhance convenience and flexibility and to reduce their medication burden.
• Data on the characteristics of patients who benefit from transitioning to extended-release buprenorphine is limited and continues to evolve. Discussion of potential risks and benefits, informed consent, and regular follow-up should be considered key components of care.
• The Health Canada-approved formulation of extended-release buprenorphine (Sublocade) is indicated for patients who have been clinically stabilized on 8mg to 24mg of sublingual buprenorphine/naloxone for a minimum of 7 days. However emerging clinical experience, represented in a number of case reports, supports the safety and tolerability of starting extended-release buprenorphine following shorter periods on buprenorphine/naloxone.
• The Sublocade Product Monograph recommends a monthly maintenance dose of 100mg following two initial monthly doses of 300mg. However, some patients (e.g., those who were previously stabilized on >24mg sublingual buprenorphine/naloxone) may benefit from an extended-release buprenorphine maintenance dose of 300mg/month.
   

Remarks:

• Due to the rapid onset of action and shorter time to peak effects (including respiratory depression) that is achieved with the injection of high-dose full agonist opioid medications, iOAT is generally self-administered in clinical settings with sterile supplies and under supervision of qualified staff trained to intervene in the event of an adverse event or emergency.
• Both diacetylmorphine and hydromorphone may be considered reasonable iOAT options. Selection may be made based on availability, patient preference, and prescriber judgement. If the individual is not benefitting from the treatment or is experiencing unacceptable side effects, they should be given the option to transition to the other medication.
• In keeping with World Health Organization recommendations for other opioid agonist treatments, iOAT should be provided as an open-ended treatment.
• Injectable opioid agonist treatment can be provided alone or with co-prescribed oral OAT to adequately address patients’ withdrawal symptoms and cravings.
   

Remarks:

• It is well-established that individuals who discontinue OAT are at increased risk of return to unregulated opioid use and related harms including drug toxicity death. Clinicians should discuss these risks with patients and advise ongoing engagement in treatment.
• Patients who expressly wish to discontinue treatment should be advised to consider a gradual taper schedule to the extent possible.
• This is based on retrospective observational data associating longer time in treatment prior to initiating taper (≥1 year vs <1 year) and a slow rate of taper (>52 weeks vs. <12 weeks) with higher rates of successful taper and lower risk of subsequent opioid overdose.
   

Remarks:

• Patients who plan to discontinue OAT should receive information on the full range of pharmacological and non-pharmacological strategies to reduce the risk of return to unregulated opioid use and related harms, including drug toxicity death.
• Pharmacological strategies to consider may include:
  • Prescribing PRN buprenorphine/naloxone (i.e., a small “pill-in-pocket” supply to facilitate re-induction)
  • Offering PO naltrexone as maintenance treatment
• Non-pharmacological relapse prevention measures may include referral to psychosocial treatment interventions and community-based supports and programs.
• Patients should be informed that both oral naltrexone and psychosocial interventions have limited effectiveness as standalone treatment strategies. Close monitoring and other relapse prevention approaches, such as PRN buprenorphine/naloxone, should be considered in addition to any other selected relapse prevention approach.