Methadone (Trade name: Methadose) is a synthetic mu-opioid agonist, similar to morphine. Methadone is used in the treatment opioid use disorder, but prolonged use of methadone itself can also result in dependence.
Absorption | Well absorbed following oral administration. The bioavailability of methadone ranges between 36 to 100%. |
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Distribution | 1 to 8 L (mostly in plasma and blood) |
Metabolism | Hepatic, via cytochrome P450 enzymes |
Elimination | Excreted mainly in the urine |
Half-life | 25 hours |
Substrate of (Metabolized by) | 3A4, 2B6, and 2C19 (lesser extent by CYP2C9 and CYP2D6) |
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Induces | - |
Inhibits | - |
Suboxone (buprenorphine/naloxone) has the following advantages over methadone:
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Guideline | Location | Year | Website | |
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Canadian Medical Association Journal (CMAJ) | Canada | 2018 | - | Link |
BC Centre on Substance Use (BCCSU) | Canada | 2023 | Link | Link |
META:PHI | Canada | 2019 | Link | Link |
Canadian Guidelines on Opioid Use Disorder Among Older Adults | Canada | 2020 | Link | |
National Institute for Health and Care Excellence (NICE) | UK | 2007 | - | Link |
American Psychiatric Association | USA | 2006, 2007 | - | • Guideline (2006) • Guideline Watch (2007) • Quick Reference |