Given the significant pharmacologic and pharmacokinetic differences among OAT medications, practice standards for take-home dosing have been informed by each medication’s safety profile based on the best available data. Overall, methadone has been represented in significantly more overdose deaths than buprenorphine,120,173,174 which has led to differing regulations for dose dispensation and monitoring.
Take-home dosing has become a standard approach for buprenorphine/naloxone treatment, whereas methadone and slow-release oral morphine treatment have remained heavily reliant on the use of daily witnessed ingestion (DWI), with graduated take-home dosing provided only when patient stability is clearly demonstrated and routinely assessed.192,246
Existing protocols that emphasize supervised dosing and restrictive criteria for methadone carries cite research associating witnessed dosing with decreased risk of methadone diversion and methadone-involved overdose.176,178,180,181 For example, a 2010 analysis of methadone-involved deaths (n=5624) across England and Scotland between 1993 and 2008 reported that the adoption of supervised dosing policies after 1995 was associated with a four-fold reduction in methadone-related overdose deaths per defined daily dose of methadone administered, in both countries.178 However, a 2017 systematic review (N=6 studies; n=7999 participants) evaluating DWI compared to take-home dosing for individuals on OAT with methadone and buprenorphine found no evidence showing a difference in rates of medication diversion between those who did and did not receive carries, in either buprenorphine or methadone groups.247 Emphasizing the small number and low quality of studies, the authors called for more research to assess the risk of diversion and the impact of supervised and unsupervised dosing on patient and public safety.247
Although more robust research is needed to characterize the impact of take-home dosing on rates of diversion and related safety risks, its impact on treatment engagement has been described in more detail. Quick transition to take-home buprenorphine/naloxone dosing has been shown to improve treatment adherence and retention.248,249 Conversely, restricted access to take-home methadone and SROM, and the requirement of daily travel to a pharmacy for witnessed ingestion has been widely criticized by patients and prescribers as stigmatizing and disruptive to daily life, and has been shown to act as a barrier to OAT engagement and retention.250-253
During the COVID-19 pandemic, protocols for take-home OAT dosing in both Canada and the United States were temporarily relaxed in order to facilitate social distancing and self-isolation without impeding access to OAT medications. These changes have presented an opportunity to evaluate the efficacy and safety of increased carries in the context of the current opioid overdose emergency.254 For example, in March 2020, Substance Abuse and Mental Health Services Administration (SAMHSA), issued an exception allowing prescribers to provide up to 28 consecutive days of take-home methadone doses to patients who are stable on this medication, and up to 14 methadone doses to “less stable patients”.254 In March 2022, SAMHSA extended this exemption for one year after the end of the COVID-19 Public Health Emergency in reference to reports of improved treatment engagement and patient satisfaction as a result of implementing these changes, with few incidents of unprescribed use or diversion of medication.255,256
Similarly, in Ontario, the Centre for Addiction and Mental Health (CAMH) released the COVID-19 Opioid Agonist Treatment Guidance in collaboration with META-PHI which recommended the expansion of access to take-home dosing in order to facilitate continuity of OAT during the pandemic. The CAMH guidance document encourages clinicians to utilize their clinical judgment of the patient’s clinical and psychosocial stability and ability to safely manage carries (e.g., not sedated at the time of dose dispensation, no acute psychiatric comorbidities, ability to safely store medication), rather than urine drug tests, to determine suitability for carries. Under this guidance, patients could be assessed remotely for carries, and patients who report continued use of unregulated substances would still be allowed to get carries unless they do not meet the program’s social stability criteria. Although this document did not provide specific guidance pertaining to SROM, it recommended that clinicians consider SROM carries on a case-by-case basis, modifying existing practices as needed to ensure continuity of OAT. Emerging data demonstrate a significant increase in the number of take-home doses dispensed in both Canada and the US after these changes in regulations.256-259
Most early evaluations of the impact of increased access to take-home dosing on treatment outcomes have reported no increase in adverse outcomes, such as overdose events or hospital admissions, associated with more relaxed take-home protocols.256-263 For example, a 2022 cross-sectional study reported on the experiences of Ontario-based OAT patients (n=402) and prescribers (n=100) with the modified take-home dosing criteria in the six months following the release of CAMH’s modified OAT guidance due to the pandemic.259 Participating patients were most frequently prescribed methadone (30%), while 21% were prescribed SROM and the remaining patients received buprenorphine/naloxone or a combination of OAT medications. The authors found no statistically significant differences in the likelihood of self-reported opioid overdose events, emergency department visits from substance use, or hospital admissions due to substance use between individuals who received additional take-home doses and those who did not.259 Additionally, those who received additional take-home OAT doses were no more likely to request early refills or report lost or stolen doses compared to individuals who did not receive additional unsupervised doses. The majority of prescribers (68%,) reported that providing additional take-home doses improved their relationship with their patients.259
A 2022 Ontario-based retrospective cohort study involving 5,852 participants who normally receive daily dispensed methadone also explored the impact of increased take-home doses in response to the pandemic on treatment retention and opioid-related harm.260 The results showed that the initiation of take-home methadone doses, compared to no change in carries, was significantly associated with lower risks of opioid overdose, (6.9% vs 9.5%/person-year; weighted hazard ratio [HR] 0.73; 95% confidence interval [CI]: 0.56 to 0.96), treatment discontinuation (51% vs. 63.6%; HR 0.80; 95% CI: 0.72 to 0.90), and treatment interruption (19% vs. 23.9%; HR 0.80; 95% CI: 0.67 to 0.95).260
While observational program evaluation studies to date have reported no adverse outcomes resulting from relaxed take-home dosing policies, a number of articles report an upward trend in methadone-involved overdoses in the US, which corresponds with the take-home dosing policy change.264-266 A 2023 analysis of data from the US Center for Disease Control reported a 48% increase in the number of overdoses involving methadone between 2019 and 2020.266 However, the authors also noted the overall rise of drug toxicity deaths involving other substances during this period, and acknowledged that the change in methadone-involved deaths could be attributable to factors other than modified take-home dosing policies.266 Similarly, a 2023 analysis of monthly overdose death databases reported a 51.7% increase in methadone-involved deaths where synthetic opioids were not implicated; however, due to the presence of a wide range of other substances, it was not possible to attribute these deaths to methadone alone.264 Finally, a 2022 population-level analysis found a 5.3% increase in the number of methadone exposure reports to American Association of Poison Control Centers’ National Poison Data System following the loosening of OAT regulations in response to COVID-19.265 However, the authors emphasized that many other factors (e.g., Medicare and Medicaid expansion, increased number of OAT programs during this period) may have contributed to this increase.265
The role of more flexible take-home dosing in promoting treatment engagement and retention is an increasingly significant consideration in the current opioid overdose death crisis resulting from the high toxicity of the unregulated drug supply. In this climate, the urgency of reducing the reliance of people with OUD on unregulated drugs by removing barriers to treatment engagement and retention is vitally important, especially given the current low OAT retention rates (16% retention rate beyond 12 months, according to a 2020 cohort study in BC).267
In the absence of robust data determining the optimal approach to take-home dosing, this guideline endorses more restrictive criteria and considerations for methadone and SROM carries in comparison to buprenorphine/naloxone. However, it also encourages prescribers to base decisions regarding carries on an individualized and flexible assessment of each patient’s needs and circumstances, and to consider the risk of treatment discontinuation along with other patient and public safety considerations, in keeping with the College of Physicians and Surgeons of BC’s Safe Prescribing of Opioids and Sedatives Practice Standard. To support prescribers in doing this, this guideline presents modified take-home dosing guidance adapted from META-PHI’s A New Framework for Methadone Carries: A Person-centred Evidence-informed Approach to Take-home “Carry” Dosing.
See Appendix 6 for detailed guidance on take-home dosing.