Baclofen and Acetaminophen And Codeine: 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
Baclofen
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 acetaminophen with codeine is a pain medicine, and baclofen is a muscle relaxer. Both can slow down your brain and nervous system. When you take them together, that calming effect can stack up, so you may feel very drowsy or dizzy. In some cases, breathing can slow down too much, which is the part we take seriously.
The good news is your care team can manage this. They may use the lowest dose for the shortest time and check on you more closely. Keep taking both exactly as prescribed, and call your doctor or pharmacist right away if you feel unusually sleepy, confused, or short of breath.
Additive CNS depression. Codeine (an opioid) combined with baclofen (a centrally acting skeletal muscle relaxant) produces additive sedation, respiratory depression, and hypotension; enhanced neuromuscular effects may also occur. This is a pharmacodynamic interaction, not PK-based.
- Direction: increased CNS/respiratory depressant effect.
- Severity: major; evidence: theoretical/additive.
- Management: reserve for patients lacking adequate alternatives; use lowest effective dose and shortest duration; consider reducing the dose of codeine and/or baclofen.
- Monitor: sedation level, respiratory rate, blood pressure.
- Educate patient/caregivers on signs of respiratory depression; consider prescribing naloxone.
What happens
Increased risk of profound sedation, respiratory depression, coma and death
Interaction Deep Dive
Concomitant use of codeine with drugs that are skeletal muscle relaxants and CNS depressants can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Reserve the concomitant use of codeine and CNS depressants to patients for whom alternatives are inadequate. If concomitant use is necessary, use the lowest dose and shortest duration necessary to achieve treatment goals. Consider using a lower dose of codeine or the CNS depressant and closely monitor for sedation and respiratory depression. Inform patients and caregivers of this potential interaction and educate them on the signs and symptoms of respiratory depression (including sedation). Respiratory depression may be greater than otherwise expected with concomitant skeletal muscle relaxant and hence decrease the dosage of codeine and/or the muscle relaxant as necessary. If concomitant use is warranted, consider prescribing naloxone for the emergency treatment of opioid overdose12.
Why it happens (mechanism)
Enhanced neuromuscular blockade; additive CNS depression
How to manage this interaction
This combination is sometimes needed, and your care team can manage it safely.
- Keep taking both as prescribed unless your doctor tells you otherwise. Do not stop or change doses on your own.
- Your team may use the lowest dose for the shortest time and may adjust the dose of the codeine and/or baclofen, individualized for you.
- They may monitor you more closely for drowsiness and slowed breathing.
- Your doctor may consider prescribing naloxone as a safety measure.
Call your pharmacist or prescriber right away if you notice heavy sedation, confusion, slow or shallow breathing, or dizziness when standing.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) Observational research has shown that taking opioid analgesics together with benzodiazepines raises the likelihood of drug-related death compared with using opioid analgesics by themselves. Given comparable pharmacological characteristics, it is logical to anticipate a similar risk when other CNS depressant medications are used alongside opioid analgesics 12.
Common questions
Can I take Baclofen and Acetaminophen And Codeine together?
Taking acetaminophen with codeine alongside baclofen can add up to dangerous drowsiness and slowed breathing, so use both only as prescribed and watch for excess sedation. Your care team can manage this with lower doses and closer monitoring. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Baclofen 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 Baclofen and Acetaminophen And Codeine interaction managed?
This combination is sometimes needed, and your care team can manage it safely. Keep taking both as prescribed unless your doctor tells you otherwise. Do not stop or change doses on your own. Your team may use the lowest dose for the shortest time and may adjust the dose of the codeine and/or baclofen, individualized for you. They may monitor you more closely for drowsiness and slowed breathing. Yo… 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 Baclofen 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 (2)
- 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 Baclofen
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