Krausz RM, Westenberg JN, Ziafat K. The opioid overdose crisis as a global health challenge. Curr Opin Psychiatry. 2021;34(4):405–12.

Article  PubMed  Google Scholar 

Chaillon A, Bharat C, Stone J, Jones N, Degenhardt L, Larney S, et al. Modeling the population-level impact of opioid agonist treatment on mortality among people accessing treatment between 2001 and 2020 in New South Wales Australia. Addict. 2022;117(5):1338–52.

Article  Google Scholar 

Kuo Y-F, Baillargeon J, Raji MA. Overdose deaths from nonprescribed prescription opioids, heroin, and other synthetic opioids in Medicare beneficiaries. J Subst Abuse Treat. 2021;124:108282.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Spencer MR, Warner M, Bastian BA. Drug overdose deaths involving fentanyl, 2011–2016. Natl Vital Stat Rep. 2019;68(3):1–9.

PubMed  Google Scholar 

Pearce LA, Min JE, Piske M, Zhou H, Homayra F, Slaunwhite A, et al. Opioid agonist treatment and risk of mortality during opioid overdose public health emergency: Population based retrospective cohort study. BMJ. 2020;368(March):1–13.

Google Scholar 

Krawczyk N, Mojtabai R, Stuart EA, Fingerhood M, Agus D, Lyons BC, et al. Opioid agonist treatment and fatal overdose risk in a state-wide US population receiving opioid use disorder services. Addiction. 2020;115(9):1683–94.

Article  PubMed  PubMed Central  Google Scholar 

Srivastava A, Kahan M. Methadone induction doses: are our current practices safe? J Addict Dis. 2006;25(3):5–13.

Article  PubMed  Google Scholar 

Pilgrim JL, McDonough M, Drummer OH. A review of methadone deaths between 2001 and 2005 in Victoria. Australia Forensic Sci Int. 2013;226(1–3):216–22.

Article  PubMed  Google Scholar 

Buster MCA, van Brussel GHA, van den Brink W. An increase in overdose mortality during the first 2 weeks after entering or re-entering methadone treatment in Amsterdam. Addiction. 2002;97(8):993–1001.

Article  PubMed  Google Scholar 

Cousins G, Teljeur C, Motterlini N, McCowan C, Dimitrov BD, Fahey T. Risk of drug-related mortality during periods of transition in methadone maintenance treatment: a cohort study. J Subst Abuse Treat. 2011;41(3):252–60.

Article  PubMed  Google Scholar 

Buresh M, Nahvi S, Steiger S, Weinstein ZM. Adapting methadone inductions to the fentanyl era. J Subst Abuse Treat. 2022;27(141):108832.

Article  Google Scholar 

Bromley L, Kahan M, Regenstreif L, Srivastava A, Wyman J. Methadone treatment for people who use fentanyl: Recommendations. Toronto, Ontario: META:PHI; 2021. https://www.metaphi.ca/wp-content/uploads/Guide_MethadoneForFentanyl.pdf. Accessed Jan 2021

Hämmig R, Köhler W, Bonorden-Kleij K, Weber B, Lebentrau K, Berthel T, et al. Safety and tolerability of slow-release oral morphine versus methadone in the treatment of opioid dependence. J Subst Abuse Treat. 2014;47(4):275–81.

Article  PubMed  Google Scholar 

Beck T, Haasen C, Verthein U, Walcher S, Schuler C, Backmund M, et al. Maintenance treatment for opioid dependence with slow-release oral morphine: a randomized cross-over, non-inferiority study versus methadone. Addiction. 2014;109(4):617–26.

Article  PubMed  PubMed Central  Google Scholar 

Jegu J, Gallini A, Soler P, Montastruc J-L, Lapeyre-Mestre M. Slow-release oral morphine for opioid maintenance treatment: a systematic review. Br J Clin Pharmacol. 2011;71(6):832–43.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Turner SD, Lurie E, Nader M. Rapid methadone and concurrent slow-release oral morphine titration in a pregnant fentanyl user. Can J Addict. 2021;12(1):29.

Article  Google Scholar 

Centre for Addiction and Mental Health. Opioid Agonist Therapy: a synthesis of Canadian guidelines for treating opioid use disorder. 2021. https://www.camh.ca/-/media/files/professionals/canadian-opioid-use-disorder-guideline2021-pdf.pdf. Accessed Jan 2021

Sordo L, Barrio G, Bravo MJ, Indave BI, Degenhardt L, Wiessing L, et al. Mortality risk during and after opioid substitution treatment: systematic review and meta-analysis of cohort studies. BMJ. 2017;357(20):j1550.

Article  PubMed  PubMed Central  Google Scholar 

Villafranca SW, McKellar JD, Trafton JA, Humphreys K. Predictors of retention in methadone programs: a signal detection analysis. Drug Alcohol Depend. 2006;83(3):218–24.

Article  PubMed  Google Scholar 

Griffiths S, Campbell DM, Caudarella A, Guimond T, Lamba W, Lurie E, et al. Use of injectable opioid agonist therapy in a in-patient setting for a pregnant patient with opioid use disorder: a case report. J Addict Med. 2020. https://doi.org/10.1097/ADM.0000000000000776.

Article  PubMed  PubMed Central  Google Scholar 

Ickowicz S, McLean M. Case report: rapid inpatient methadone titration during pregnancy. J Subst Use. 2021;15:1–4.

Google Scholar 

Hemmons P, Bach P, Colizza K, Nolan S. initiation and rapid titration of methadone in an acute care setting for the treatment of opioid use disorder: a case report. J Addict Med. 2019;13(5):408–11.

Article  PubMed  PubMed Central  Google Scholar 

Snyder DCKH. Inpatient management of opioid use disorder: methadone (SHOUT Guidelines). University of California San Francisco; 2017. https://www.chcf.org/wp-content/uploads/2018/03/SHOUTGuidelinesInpatientOpioidTreatmentMethadone.pdf. Accessed Jan 2021

Minozzi S, Amato L, Jahanfar S, Bellisario C, Ferri M, Davoli M. Maintenance agonist treatments for opiate-dependent pregnant women. Cochrane Database Syst Rev. 2020;11:CD006318.

PubMed  Google Scholar 

Wang MJ, Kuper SG, Sims B, Paddock CS, Dantzler J, Muir S, et al. Opioid detoxification in pregnancy: systematic review and meta-analysis of perinatal outcomes. Am J Perinatol. 2019;36(6):581–7.

Article  PubMed  Google Scholar 

Minozzi S, Amato L, Vecchi S, Davoli M. Maintenance agonist treatments for opiate dependent pregnant women. Cochrane Database Syst Rev. 2008. https://doi.org/10.1002/14651858.CD006318.pub2.

Article  PubMed  Google Scholar 

Burns L, Conroy E, Mattick RP. Infant mortality among women on a methadone program during pregnancy. Drug Alcohol Rev. 2010;29(5):551–6.

Article  PubMed  Google Scholar 

Toronto’s Drug Checking Service. Toronto’s drug checking service. 2020. https://drugchecking.cdpe.org/. Accessed 28 Aug 2022.

von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP. The strengthening the reporting of observational studies in epidemiology (STROBE) statement: guidelines for reporting observational studies. Int J Surg. 2014;12(12):1495–9.

Article  Google Scholar 

City of Toronto. City of Toronto income—median total household income 2015. https://www.toronto.ca/wp-content/uploads/2018/06/9700-ct16_TOR_Income_pretaxInc.pdf. Accessed 28 Aug 2022.

Eder H, Jagsch R, Kraigher D, Primorac A, Ebner N, Fischer G. Comparative study of the effectiveness of slow-release morphine and methadone for opioid maintenance therapy. Addiction. 2005;100(8):1101–9.

Article  PubMed  Google Scholar 

Stone AC, Carroll JJ, Rich JD, Green TC. Methadone maintenance treatment among patients exposed to illicit fentanyl in Rhode Island: safety, dose, retention, and relapse at 6 months. Drug Alcohol Depend. 2018;1(192):94–7.

Article  Google Scholar 

Collett BJ. Opioid tolerance: the clinical perspective. Br J Anaesth. 1998;81(1):58–68.

Article  CAS  PubMed  Google Scholar 

Crabtree A, Lostchuck E, Chong M, Shapiro A, Slaunwhite A. Toxicology and prescribed medication histories among people experiencing fatal illicit drug overdose in British Columbia. Canada CMAJ. 2020;192(34):E967–72.

Article  CAS  Google Scholar 

McCarthy JJ, Leamon MH, Parr MS, Anania B. High-dose methadone maintenance in pregnancy: maternal and neonatal outcomes. Am J Obstet Gynecol. 2005;193(3):606–10.

Article  CAS  PubMed  Google Scholar 

Wilder CM, Hosta D, Winhusen T. Association of methadone dose with substance use and treatment retention in pregnant and postpartum women with opioid use disorder. J Subst Abuse Treat. 2017;80:33–6.

Article  PubMed  Google Scholar 

World Health Organization. Guidelines for the psychosocially assisted pharmacological treatment of opioid dependence. Geneva: World Health Organization; 2009. p. 110.

Google Scholar 

O’Connor AM, Cousins G, Durand L, Barry J, Boland F. Retention of patients in opioid substitution treatment: a systematic review. PLoS ONE. 2020;15(5):e0232086.

Article  PubMed  PubMed Central  Google Scholar 

Jones HE, Finnegan LP, Kaltenbach K. Methadone and buprenorphine for the management of opioid dependence in pregnancy. Drugs. 2012;72(6):747–57.

Article  CAS  PubMed  Google Scholar 

Wilder C, Lewis D, Winhusen T. Medication assisted treatment discontinuation in pregnant and postpartum women with opioid use disorder. Drug Alcohol Depend. 2015;1(149):225–31.

Article  Google Scholar 

Braithwaite V, Fairgrieve C, Nolan S. Sustained-release oral hydromorphone for the treatment of opioid use disorder. J Addict Med. 2020;14(4):345–7.

Article  PubMed  PubMed Central  Google Scholar 

Shiu JR, Ensom MHH. Dosing and monitoring of methadone in pregnancy: literature review. Can J Hosp Pharm. 2012;65(5):380–6.

PubMed  PubMed Central  Google Scholar 

Wolff K, Boys A, Rostami-Hodjegan A, Hay A, Raistrick D. Changes to methadone clearance during pregnancy. Eur J Clin Pharmacol. 2005;61(10):763–8.

Article  CAS  PubMed  Google Scholar