Levodopa and Acetaminophen And Codeine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Levodopa
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 prescribed acetaminophen with codeine (a pain reliever that contains an opioid) along with levodopa for Parkinson's symptoms. The concern here is simple: both of these can slow down your brain and nervous system. When taken together, that calming effect can add up, so you might feel more sleepy, dizzy, or foggy than usual.
This is a theoretical concern, meaning it's based on how the drugs work rather than lots of reported cases. Still, it's worth respecting. Please keep taking both exactly as prescribed, and let your pharmacist or doctor know if you feel unusually drowsy or lightheaded. Your care team can manage this easily.
Effect: Additive CNS depression when codeine (an opioid analgesic combined with acetaminophen) is coadministered with levodopa.
- Mechanism: Pharmacodynamic, additive CNS/sedative effects. Not a CYP-mediated PK interaction.
- Direction: Increased sedation, dizziness, drowsiness, and potential respiratory/CNS depression.
- Onset: Unspecified.
- Evidence: Theoretical; severity rated major on file.
- Management: Use caution when combined. Monitor for excess sedation and CNS depression, particularly in elderly or those on other depressants. Dose may be individualized and monitoring intensified by the care team.
What happens
An increased risk of CNS depression
Interaction Deep Dive
When foscarbidopa/foslevodopa is given together with CNS depressants, the likelihood of CNS depression may be heightened. Use caution if these agents are administered concurrently1.
Why it happens (mechanism)
Additive CNS depression
How to manage this interaction
What your care team may do:
- Continue both medications as prescribed unless told otherwise.
- Watch you more closely for signs of excess drowsiness or dizziness, especially when starting or changing doses.
- Individualize and adjust dosing if sedation becomes a problem.
What you can do: Avoid other things that add to drowsiness (like alcohol or other sedating medicines) unless cleared. Tell your pharmacist or doctor if you feel unusually sleepy, confused, lightheaded, or have trouble breathing. Don't stop or change either medication on your own.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
Common questions
Can I take Levodopa and Acetaminophen And Codeine together?
Taking acetaminophen/codeine with levodopa can add up to extra drowsiness and dizziness, so watch for those and keep your care team informed. This is a theoretical caution, and your team can manage it with monitoring and dose adjustments. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Levodopa and Acetaminophen And Codeine 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 Levodopa and Acetaminophen And Codeine interaction managed?
What your care team may do: Continue both medications as prescribed unless told otherwise. Watch you more closely for signs of excess drowsiness or dizziness, especially when starting or changing doses. Individualize and adjust dosing if sedation becomes a problem. What you can do: Avoid other things that add to drowsiness (like alcohol or other sedating medicines) unless cleared. Tell your pharma… 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.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Levodopa or Acetaminophen And Codeine 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: VYALEV(TM) subcutaneous injection, foscarbidopa and foslevodopa subcutaneous injection. AbbVie Inc (per FDA), North Chicago, IL, 2024. DailyMed
- Product Information: Eunerpan(R), Melperonhydrochlorid. Nordmark Arzneimittel GmbH, Uetersen, 1991.
- Product Information: Nipolept(R), zotepine. Klinge Pharma GmbH, Munich, Germany, 1994.
Keep reading about Acetaminophen And Codeine
Keep reading about Levodopa
These medications also interact with supplements
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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