Acetaminophen And Codeine and Lisdexamfetamine: 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
Lisdexamfetamine
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.
Your pain medicine contains codeine, and Vyvanse (lisdexamfetamine) is a stimulant. Both can raise a brain chemical called serotonin. When two medicines do this together, there is a small chance of a reaction called serotonin syndrome.
Signs to watch for include feeling agitated or restless, a fast heartbeat, sweating, shivering, muscle twitching or stiffness, and confusion. This is mostly a theoretical concern, meaning it is not commonly seen, but it is worth knowing about. The good news is your care team can manage this by watching you closely, especially when you first start or change a dose. If you feel any of those symptoms, contact your doctor right away.
Effect: Additive serotonergic activity from codeine (an opioid with mild serotonergic properties) plus lisdexamfetamine (a prodrug of dextroamphetamine that promotes monoamine release) may increase the risk of serotonin syndrome.
- Mechanism: Additive serotonergic effects (PD interaction).
- Direction: Increased serotonergic tone.
- Onset: Unspecified; highest risk at initiation and dose escalation.
- Evidence: Theoretical; documented in opioid + serotonergic combinations generally.
Management: If used together, monitor for hyperthermia, autonomic instability, neuromuscular findings (clonus, hyperreflexia, rigidity), and mental status changes. Discontinue codeine 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. When such combined therapy is required, monitor the patient closely, especially when starting treatment and when adjusting doses. Should serotonin syndrome be suspected, stop codeine123.
Why it happens (mechanism)
Additive serotonergic effects
How to manage this interaction
You can usually take both as prescribed, but your care team will want to keep an eye on you, especially when starting either drug or adjusting a dose.
- Keep taking both unless your prescriber tells you otherwise. Do not stop on your own.
- Watch for warning signs: agitation, fast heartbeat, sweating, shivering, muscle twitching or stiffness, fever, or confusion.
- Get help promptly if these occur, as your team may stop the codeine if serotonin syndrome is suspected.
- Tell your pharmacist or prescriber about all your medicines so your dose can be individualized and you can be monitored more closely if needed.
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 Lisdexamfetamine together?
Taking codeine-containing pain medicine with Vyvanse carries a small, mainly theoretical risk of serotonin syndrome; you can usually take both, but watch for symptoms like agitation, fast heartbeat, sweating, and muscle twitching, and contact your care team if they appear. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Lisdexamfetamine 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 Lisdexamfetamine interaction managed?
You can usually take both as prescribed, but your care team will want to keep an eye on you, especially when starting either drug or adjusting a dose. Keep taking both unless your prescriber tells you otherwise. Do not stop on your own. Watch for warning signs: agitation, fast heartbeat, sweating, shivering, muscle twitching or stiffness, fever, or confusion. Get help promptly if these occur, as y… 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 Lisdexamfetamine 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 Lisdexamfetamine
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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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