Methadone is methadone

As a pharmacist who has been dispensing methadone for more than 20 years to patients in and out of Ontario provincial jails, I read the article by Raski et al in the November issue¹ with interest (and gratitude to one of the doctors on our team, who thoughtfully clipped this article out of his paper copy of Canadian Family Physician and provided it to me). When we transitioned from methadone to Methadose in Ontario, I braced myself for patients’ reactions and prepared for some sort of backlash. What I found after the transition was that many of our patients started hearing about the complaints from people receiving methadone in British Columbia. But here in Ontario, my patients did not have this same experience.

The article does not really address in detail the main change that occurred with this transition, and issues that might arise from it: that all pharmacists in the country were compelled to stop making stock solutions from methadone powder and use the commercial product instead. I suggest the possibility that the issue with the transition to Methadose arises from the precision with which doses of methadone were formerly being prepared. The reason that provincial regulators decided to enforce Health Canada’s Policy on Manufacturing and Compounding Drug Products in Canada (2009),² and compel pharmacists to stop preparing methadone solution in the back of our pharmacies was that, regardless of our level of skill, precision, and professionalism, we do not have the same degree of quality control in our pharmacies as does Big Pharma, and mishaps, although rare, did happen. Much as it behooves me to say so, the possibility exists that the extemporaneously prepared doses of methadone did not contain the same amount of methadone as when we started using the more precisely prepared commercial product. And this dose discrepancy perhaps was for some reason most extreme in British Columbia. Otherwise, why did we barely experience this problem in Ontario?

However, there might be another explanation that arises from an examination of the entire context of illicit drug use and what drugs are available on the illicit market, and how those might affect patients. Specifically, the rollout of Methadose in 2014 happened to coincide with the increasing presence of fentanyl in the heroin supply. Most people in opioid agonist treatment programs continue to use illicitly acquired drugs. If people who use opioids start unknowingly receiving fentanyl, and they persist with this use and do not overdose from fentanyl’s 50-fold potency compared with heroin, their physical tolerance to opioids will increase; ergo, their usual dose of methadone will not be sufficient to suppress their opioid cravings. And as Vancouver, BC, is a port city, people who used opioids were likely to encounter fentanyl before most of the rest of the country. And yes, fentanyl has now unfortunately spread throughout Canada, but as it arrived in more inland cities, perhaps it more gradually supplanted other illicit drug sources than happened in Vancouver, so the tolerance of patients was more gradually affected. After all, back in the Oxycontin days, Oxycontin was the most trafficked opioid in Canada with the exception of 2 port cities: Montreal, Que, and yes, Vancouver, where heroin remained the most prevalent opioid of illicit use until fentanyl came along.

I agree with your points regarding more community consultation. People with substance use disorder are among the most vulnerable of our citizens, and they especially do not like changes being imposed upon them without negotiation or discussion. But methadone is methadone, and it does not make any sense that there would be any difference. I appreciate your thoroughness in examining whether there was any pharmaceutical difference between formulations. I suggest that this problem encountered by some patients might have a more substantiative explanation, but given the impossibility of comparing the extemporaneously prepared doses made before 2014 with the current doses, and the complexity of determining the effects of the illicit drug supply on our patients, I do not know if this is a mystery we will ever solve.

• Copyright © the College of Family Physicians of Canada