Opioid agonist therapies: What they are and what do they do

Anna Junker 4 minute read March 28, 2022

The Alberta government is expanding access to opioid agonist therapies such as methadone, suboxone, or sublocade through programs to help users quell their need for the drug.

Typically, users need to meet two or more of ‘opioid use disorder’ criteria, before they can get a prescription through a doctor, and receive treatment at a pharmacy. Some people will use the therapies for the rest of their lives, while others are able to wean off of them over time. But what exactly are these treatments and how do they work?

Postmedia spoke with Dr. Monty Ghosh, an addiction medicine physician and researcher and an assistant professor at the University of Calgary and the University of Alberta, about each of these and other therapies available in Alberta.

This interview has been edited for length and clarity.


What is methadone?

Methadone is very similar to other opioids, including fentanyl except it has a longer half-life and is very potent in comparison to things such as morphine. It’s that long half-life that’s very helpful because it prevents people from going into withdrawal. It stabilizes both cravings and withdrawals so users don’t have to use illicit drugs, so they can work on other aspects of their wellness such as mental health issues or getting housing if they’re experiencing homelessness, et cetera.

How is it administered?

The main way we do it here in Alberta is it’s usually put into an orange-flavoured Tang and people drink it once a day. The reason it’s in orange Tang is not only because it’s easier to consume because methadone itself doesn’t taste that great, but it also prevents people from injecting it into their veins. It’s usually done at the pharmacy and it’s usually witnessed up until the time they’ve had three consecutive negative urine drug screens, which are usually spaced one month apart. Then they can start to take carries home. Carries are a small container of methadone that is pre-measured you can drink at home.


What is suboxone?

The proper name is buprenorphine. It’s what we call a partial agonist. When you look at methadone, morphine or fentanyl, those are what we call full agonists. They have full qualities of an opioid and then on the flip side of things, we have the opioid antagonists, which are like naltrexone, Naloxone, so like the antidote to an opioid overdose because they compete with the full agonist. Buprenorphine is essentially in between.

How is it administered?

It’s a tablet that you put into your tongue and it dissolves. There are a few different forms of it now, there’s a film that you can put in your cheeks, a form that you inject into your skin and it lasts about a month, and there’s a fourth form which is like a rod, that is placed in your arm and can last for six months.

It’s very tricky to get people started on buprenorphine because it can cause people to go into forced withdrawal, and that’s called precipitated withdrawal. That’s because of the partial antagonistic activity that it has. You have to be very careful as to how you get people on this drug. So usually, people have to be in withdrawal first, and then you get them on it.

How does it compare to methadone?

There are comparison studies between buprenorphine and methadone and methadone is usually superior in preventing people from having relapses and keeping people off of illicit substances. But there’s a higher risk of overdose with methadone compared to buprenorphine.

The reason why it’s preferred over methadone as the first-line treatment is because it has what we call a ceiling effect. So it’s just a fancy way of saying because it has a partial antagonistic activity to it, like Naloxone, people can’t overdose on it.


What is Sublocade?

It is the injectable form of Suboxone. Typically you want to get someone stabilized on Suboxone first, as quick as possible. Once they’re stable, you can get them on the Sublocade. It takes us about one day to get someone stabilized on Suboxone so they can get started.

How does it compare to Suboxone?

It lasts 30 days. Some complaints I’ve heard is if you’re putting it into your tummy, it leaves a bit of a lump where the injection is and some people don’t like that. It does go away though over time. Suboxone is more widely accessible. There’s more physicians who prescribe it, and there’s fewer restrictions for physicians to prescribe it.




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