Acetaminophen And Codeine and Methamphetamine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Methamphetamine
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
You've been given a medicine that combines acetaminophen with codeine (a pain reliever) along with methamphetamine (Desoxyn). Both of these can raise levels of a brain chemical called serotonin. When two medicines do that together, there's a small chance of a reaction called serotonin syndrome.
Signs to watch for include feeling agitated or confused, a fast heartbeat, sweating, shaking, muscle twitching, or a fever. This is mostly a theoretical concern, and many people take medicines like these without a problem. Your care team can manage it by watching you closely, especially when you first start or change a dose. If you notice those symptoms, call your doctor right away.
Effect: Additive serotonergic activity increasing the theoretical risk of serotonin syndrome.
Mechanism: Codeine is a weak serotonin reuptake inhibitor; methamphetamine promotes monoamine (including serotonin) release. Combined, serotonergic tone may rise. This is a pharmacodynamic interaction, not PK based.
- Direction/magnitude: Additive effect; magnitude unquantified.
- Onset: Unspecified; highest risk at initiation and dose escalation.
- Evidence: Theoretical.
Management: If used together, monitor for clonus, hyperreflexia, agitation, autonomic instability, and hyperthermia. Discontinue codeine and treat supportively if serotonin syndrome is suspected.
What happens
Increased risk of serotonin syndrome
Interaction Deep Dive
Serotonin syndrome has been reported when opioids like codeine are taken together with serotonergic agents. Should combined therapy be required, monitor the patient closely, especially when starting treatment and when doses are being modified. If serotonin syndrome is suspected, stop codeine123.
Why it happens (mechanism)
Additive serotonergic effects
How to manage this interaction
If your care team decides you need both medicines, the plan is straightforward:
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may watch you more closely, especially when starting either drug or changing a dose.
- Doses may be adjusted and individualized by your care team as needed.
Call your pharmacist or prescriber and seek care promptly if you notice agitation, confusion, a racing heart, heavy sweating, shivering, muscle twitching or stiffness, or a fever. These can be early signs, and stopping the codeine usually resolves them.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
Common questions
Can I take Acetaminophen And Codeine and Methamphetamine together?
Taking acetaminophen/codeine with methamphetamine carries a theoretical risk of serotonin syndrome from added serotonin effects. Keep taking both as prescribed, watch for agitation, sweating, fast heartbeat, tremor, or fever, and contact your care team if these appear. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Methamphetamine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Acetaminophen And Codeine and Methamphetamine interaction managed?
If your care team decides you need both medicines, the plan is straightforward: Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your team may watch you more closely, especially when starting either drug or changing a dose. Doses may be adjusted and individualized by your care team as needed. Call your pharmacist or prescriber and seek care promptly if you notic… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Acetaminophen And Codeine or Methamphetamine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (3)
- Product Information: Codeine sulfate oral tablets, codeine sulfate oral tablets. West-Ward Pharmaceuticals Corp (per DailyMed), Eatontown, NJ, 2016. DailyMed
- Product Information: Codeine sulfate oral solution, codeine sulfate oral solution. Hikma Pharmaceuticals USA Inc(per FDA), Berkeley Heights, NJ, 2023. DailyMed
- Product Information: Codeine sulfate oral tablets, codeine sulfate oral tablets. Hikma Pharmaceuticals USA Inc. (per FDA), Berkeley Heights, NJ, 2023. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Methamphetamine
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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