Carbidopa 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
Carbidopa
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 two medicines here: acetaminophen with codeine (a pain reliever that contains an opioid) and carbidopa (used with levodopa for Parkinson's symptoms). The concern is that codeine can make you feel drowsy or slow your breathing, and the combination may add to that sleepy, sluggish feeling.
The good news is this warning is based on theory, not strong real-world reports. Still, watch for extra drowsiness, dizziness, or trouble concentrating, especially when you first start. Your care team can manage this easily by tailoring your doses and keeping an eye on how you feel, so keep taking both exactly as prescribed and let them know about any new sleepiness.
Effect: Potential additive CNS depression when acetaminophen/codeine (opioid analgesic) is combined with carbidopa-containing therapy.
Mechanism: Additive pharmacodynamic CNS depression; the opioid component (codeine) contributes sedation and respiratory depression.
- Direction: Increased sedative/CNS-depressant burden.
- Onset: Unspecified.
- Evidence: Theoretical.
- Magnitude: Not quantified.
Management: Use caution with concurrent use. Monitor for excess sedation, dizziness, and respiratory depression. Doses may be adjusted and individualized; counsel on additive sedation and avoiding other CNS depressants (alcohol, benzodiazepines) without guidance.
What happens
An increased risk of CNS depression
Interaction Deep Dive
Coadministration of foscarbidopa/foslevodopa and CNS depressants may increase risk of CNS depression. Exert caution when coadministered1.
Why it happens (mechanism)
Additive CNS depression
How to manage this interaction
Keep taking both as prescribed unless your care team tells you otherwise. This is a caution, not a reason to stop on your own.
- Watch for added drowsiness, dizziness, slowed breathing, or trouble staying alert, especially early on.
- Your team may monitor you more closely and, if needed, adjust and individualize your doses.
- Avoid alcohol and other sedating medicines unless your pharmacist or doctor approves.
- Tell your pharmacist or prescriber about any new or worsening sleepiness so they can help.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Carbidopa and Acetaminophen And Codeine together?
Combining acetaminophen/codeine with carbidopa may add to drowsiness and other CNS depressant effects, so watch for extra sedation and let your care team monitor and adjust as needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Carbidopa 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 Carbidopa and Acetaminophen And Codeine interaction managed?
Keep taking both as prescribed unless your care team tells you otherwise. This is a caution, not a reason to stop on your own. Watch for added drowsiness, dizziness, slowed breathing, or trouble staying alert, especially early on. Your team may monitor you more closely and, if needed, adjust and individualize your doses. Avoid alcohol and other sedating medicines unless your pharmacist or doctor a… 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 Carbidopa 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 (1)
- Product Information: VYALEV(TM) subcutaneous injection, foscarbidopa and foslevodopa subcutaneous injection. AbbVie Inc (per FDA), North Chicago, IL, 2024. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Carbidopa
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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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