Acetaminophen And Codeine and Aclidinium: 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
Aclidinium
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, which can slow down your gut and make you constipated. Aclidinium (Tudorza) is an inhaler that also slows the gut and can make it harder to empty your bladder. When you take them together, those effects can add up. In rare cases, the bowel can slow down so much that it nearly stops, which is called a paralytic ileus.
This concern is based on how the two drugs work, not on lots of real-world reports, so please don't worry. Just watch for bad constipation, belly swelling or pain, or trouble urinating, and let your pharmacist or doctor know. They can easily manage this.
Effect: Additive anticholinergic-type slowing of GI motility. Codeine (an opioid) reduces gut motility, and aclidinium (an inhaled long-acting muscarinic antagonist) has anticholinergic effects that can compound constipation and urinary retention, theoretically progressing to paralytic ileus.
- Mechanism: Pharmacodynamic (additive reduced gastric motility / antimuscarinic effect), not a metabolic interaction.
- Direction: Increased GI/urinary adverse effects.
- Evidence: Theoretical; severity rated major.
- Onset: Unspecified.
- Management: Monitor for reduced bowel motility, abdominal distension/pain, and urinary retention. Ensure bowel regimen; individualize therapy.
What happens
An increased risk of paralytic ileus
Interaction Deep Dive
Concomitant use of codeine with anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor patients for signs of urinary retention or reduced gastric motility when codeine is used concomitantly with anticholinergic drugs1.
Why it happens (mechanism)
Additive effects on gastric motility
How to manage this interaction
This interaction can usually be managed well. Keep taking both medicines as prescribed unless your care team tells you otherwise.
- Watch for severe constipation, bloating, belly pain, or trouble urinating and report these promptly.
- Staying hydrated and, if your team agrees, using a stool softener or laxative can help keep your bowels moving.
- Your care team may monitor you more closely or adjust and individualize your treatment while you use both.
- Contact your pharmacist or prescriber before making any changes on your own.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Aclidinium together?
Taking codeine with aclidinium (Tudorza) can add up to worse constipation and possible urinary retention, so watch for these and call your care team if they happen. Keep taking both as prescribed unless told otherwise. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Aclidinium 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 Aclidinium interaction managed?
This interaction can usually be managed well. Keep taking both medicines as prescribed unless your care team tells you otherwise. Watch for severe constipation, bloating, belly pain, or trouble urinating and report these promptly. Staying hydrated and, if your team agrees, using a stool softener or laxative can help keep your bowels moving. Your care team may monitor you more closely or adjust and… 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 Aclidinium 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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