Acetaminophen And Codeine and Umeclidinium: 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
Umeclidinium
No brand names on record
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, an opioid, and your inhaler contains umeclidinium. Both of these can slow down your gut and make it harder to empty your bladder. When you take them together, those effects can add up, so you may notice more constipation or trouble urinating. In rare cases, the bowel can slow so much that it nearly stops moving (called a paralytic ileus).
The good news is this is a possible risk, not a sure thing, and it is easy to watch for. Keep taking both as prescribed, drink fluids, stay active if you can, and let your pharmacist or doctor know if you get badly backed up or can't pass urine. Your care team can manage this.
Effect: Additive anticholinergic and opioid-related reduction in GI motility, with theoretically increased risk of severe constipation, urinary retention, and paralytic ileus.
Mechanism: Codeine (opioid mu-agonist) slows gut transit; umeclidinium is a long-acting muscarinic antagonist. Combined effect on gastric/bowel motility and bladder emptying is additive (pharmacodynamic).
- Direction: Increased anticholinergic/constipating burden.
- Onset: Unspecified.
- Evidence: Theoretical.
- Severity: Major.
Management: Monitor for reduced gastric motility, abdominal distension, and urinary retention. Consider prophylactic bowel regimen; individualize therapy and escalate if obstructive symptoms appear.
What happens
An increased risk of paralytic ileus
Interaction Deep Dive
When codeine is taken together with anticholinergic agents, there may be a heightened chance of urinary retention and/or severe constipation, potentially progressing to paralytic ileus. Patients receiving codeine alongside anticholinergic drugs should be watched for indications of urinary retention or diminished gastric motility1.
Why it happens (mechanism)
Additive effects on gastric motility
How to manage this interaction
Both medicines can slow your digestion and bladder, so the main plan is simple watchfulness.
- Keep taking both as prescribed unless your doctor tells you otherwise.
- Watch for worsening constipation, bloating, belly pain, or trouble urinating.
- Support your gut with fluids, fiber, and movement; your team may suggest a stool softener or laxative.
- Your care team may monitor you more closely and can adjust and individualize your plan.
Call your pharmacist or doctor right away if you cannot have a bowel movement, cannot pass urine, or have severe belly pain and swelling.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Umeclidinium together?
Codeine and umeclidinium can both slow the gut and bladder, so together they may cause severe constipation or urinary retention. Keep taking both as prescribed, stay hydrated and active, and report any severe constipation, belly swelling, or trouble urinating to your care team. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Umeclidinium 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 Umeclidinium interaction managed?
Both medicines can slow your digestion and bladder, so the main plan is simple watchfulness. Keep taking both as prescribed unless your doctor tells you otherwise. Watch for worsening constipation, bloating, belly pain, or trouble urinating. Support your gut with fluids, fiber, and movement; your team may suggest a stool softener or laxative. Your care team may monitor you more closely and can adj… 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 Umeclidinium 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: CARISOPRODOL, ASPIRIN, CODEINE PHOSPHATE oral tablets, carisoprodol, aspirin, codeine phosphate oral tablets. Ingenus Pharmaceuticals LLC (per DailyMed), Orlando, FL, 2021. DailyMed
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