Acetaminophen And Codeine and Ipratropium: 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
Ipratropium
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.
You've been prescribed acetaminophen with codeine (a pain reliever) along with ipratropium (a breathing medicine). Both of these can slow down your gut and make your bladder empty less easily. When taken together, that slowing effect can add up, and in rare cases it can lead to severe constipation, trouble urinating, or a serious problem where the bowel stops moving.
The good news is this is mostly a theoretical concern, and it's very manageable. Keep taking both as prescribed, stay hydrated, and let your care team know if you notice belly bloating, no bowel movements, or trouble peeing. They can watch for this and adjust things if needed.
Effect: Additive reduction in gastrointestinal and urinary tract motility, theoretically increasing risk of severe constipation, urinary retention, and paralytic ileus.
Mechanism: Codeine (opioid agonist) reduces GI motility; ipratropium adds anticholinergic effects on smooth muscle. Effects are additive, not PK-mediated.
- Direction: Increased constipating/retentive effect.
- Evidence: Theoretical; severity rated major.
- Onset: Unspecified.
- Management: Monitor for reduced gastric motility, abdominal distension, and urinary retention. Consider prophylactic bowel regimen and adequate hydration. Dose/therapy may be individualized by the care team.
What happens
An increased risk of paralytic ileus
Interaction Deep Dive
When codeine is taken alongside anticholinergic agents, the likelihood of urinary retention and/or severe constipation may rise, potentially progressing to paralytic ileus. Patients receiving codeine together with 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
Keep taking both medications as prescribed unless your prescriber tells you otherwise. This interaction is a precaution, and your care team can manage it easily.
- Watch for severe constipation, no bowel movements, belly bloating or cramping, and trouble urinating.
- Drink fluids and stay active as you're able; ask your pharmacist whether a stool softener is appropriate for you.
- Report any of the above symptoms promptly so your team can monitor you more closely and adjust your medicines if needed.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Ipratropium together?
Taking codeine with ipratropium can add up to slow your gut and bladder, so watch for severe constipation or trouble urinating and tell your care team if they happen. Keep taking both as prescribed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Ipratropium 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 Ipratropium interaction managed?
Keep taking both medications as prescribed unless your prescriber tells you otherwise. This interaction is a precaution, and your care team can manage it easily. Watch for severe constipation, no bowel movements, belly bloating or cramping, and trouble urinating. Drink fluids and stay active as you're able; ask your pharmacist whether a stool softener is appropriate for you. Report any of the abov… 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 Ipratropium 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
Keep reading about Acetaminophen And Codeine
Keep reading about Ipratropium
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