Mixing Fentanyl and Methadone
Dangerous
Yesterday's methadone is still active, and fentanyl on top of it is a common way people die, especially in the first two weeks of treatment. Do not combine. Keep naloxone nearby.
Methadone accumulates over days and stays active far longer than it feels active. Fentanyl on top of a methadone dose from yesterday is a common and frequently fatal pattern, particularly in the first two weeks of methadone treatment before levels have stabilised.
The risk here is to the body — breathing, heart, temperature or organs. Set limits before you start, because this kind of harm does not announce itself in time to react.
Headspace vs physical riskWhat to do
- Say what was taken and how much.Responders need it, and in most US states Good Samaritan laws protect both of you from drug possession charges when you call for an overdose.
- Unresponsive: put them on their side, tilt the head back, and stay until help arrives.Never leave someone alone to “sleep it off”.
- Give naloxone (Narcan) if you have it.It is sold over the counter in every US state and does no harm if opioids turn out not to be involved.
- Never Use Alone 1-800-484-3731Stays on the line and sends help if you stop responding.
- Full steps: what to do if it is already happeningOverdose signs, the recovery position, what to say on the call, and whether you can be charged for making it.
- Poison Control 1-800-222-1222Free and 24/7, for “is this bad?” before it becomes an emergency.
Can you mix Fentanyl and Methadone?
MixSafe rates mixing Fentanyl and Methadone as "Dangerous" — high risk of death or life-changing injury. Do not combine. Source: MixSafe research. Educational information, not medical advice.
- Fentanyl
- Synthetic — potent by micrograms, unevenly mixed
- Methadone
- Long-acting — outlasts its own effects by many hours
- Fentanyl also called
- fent, fentanil, carfentanil, nitazene, nitazenes, duragesic
- Methadone also called
- dolophine, methadose, done
- QT prolongation with methadone. https://pmc.ncbi.nlm.nih.gov/articles/PMC2760917/
- Methadone Safety: A Clinical Practice Guideline From the American Pain Society and College on Problems of Drug Dependence, in Collaboration With the Heart Rhythm Society. https://www.sciencedirect.com/science/article/pii/S1526590014005227
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Checking more than two?
Combinations of three or more carry risks that no pair-by-pair chart can show. The checker rates every pair at once and flags the whole-mix ones on top.
Open this in the checkerRelated combinations
All combinations →Rated dangerous. Educational information only, not medical advice. Absence of a documented interaction is not evidence of safety.