Understanding OAT Medications — A Reference Guide
Methadone, Kadian and Suboxone side by side — how each works, how they differ, and what to ask your prescriber. A quick reference, not a replacement for the conversation.
Opioid agonist treatment uses one of three medications in British Columbia. This is a reference — a place to look something up — rather than a step-by-step guide. For what starting treatment actually involves, see our blog post on what to expect.
The three medications at a glance
Once-daily oral liquid. Long track record. Started low and increased slowly over weeks. Interacts with a long list of other medications — always disclose everything you take.
Once-daily capsule, slow-release oral morphine. An option when methadone or Suboxone has not been a good fit. Must be swallowed whole — never crushed or chewed.
Buprenorphine/naloxone, dissolved under the tongue. First-line in BC due to a safer overdose profile. Must be started once you are already in mild withdrawal.
How they compare
- ✓Overdose risk — Suboxone has a ceiling effect on breathing suppression that methadone and Kadian do not, which is why it is generally considered the safer starting point.
- ✓Starting process — methadone and Kadian are started directly; Suboxone requires waiting until you are in mild withdrawal first, or it can trigger a sudden, severe withdrawal reaction.
- ✓Take-home doses — timing for authorised carries depends on your prescriber's assessment of stability, not the medication alone, though Suboxone's safety profile often allows it sooner.
- ✓Switching between them — common and manageable, but needs to be planned with your prescriber rather than attempted alone, especially moving to or from methadone.
Questions worth asking your prescriber
- 1Why this medication rather than one of the others, given my situation?
- 2What should I expect in the first two weeks?
- 3What interacts with this — including things I might not think to mention, like sleep medication or antibiotics?
- 4When might I be considered for take-home doses?
- 5What happens if I miss a dose, or several?
Where to go from here
This page is a reference, not a decision. Which medication is right for you is a conversation between you and your prescriber, and Argyle Pharmacy can help you have it — including connecting you with a prescriber if you do not have one yet.
Medical Disclaimer: The information in this guide is intended for general reference only and does not constitute medical advice. Always consult your pharmacist or physician before making any changes to your medications, treatments, or health routine.
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