Dicyclomine 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
Dicyclomine
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, and dicyclomine (Bentyl) is used to calm stomach cramps. The catch is that both can slow down your gut and bladder. Used together, they can make constipation worse and make it harder to empty your bladder. In rare cases, the gut can slow so much that it nearly stops moving, which is called a paralytic ileus.
This is a theoretical concern, meaning it is based on how these drugs work rather than lots of reports, but it is worth watching. Please keep taking both as prescribed and let your care team know if you have belly bloating, no bowel movements, or trouble urinating. They can manage this easily.
Effect: Additive anticholinergic and opioid-related reduction in GI motility, increasing risk of severe constipation, urinary retention, and potentially paralytic ileus.
Direction/mechanism: Codeine (mu-opioid agonist) slows gut transit; dicyclomine (antimuscarinic) adds anticholinergic suppression of motility and bladder function. Pharmacodynamic, additive, not a CYP-based PK interaction. Neither agent's activation is relevant here.
- Severity: Major
- Evidence: Theoretical
- Onset: Unspecified
Management: Monitor for reduced bowel sounds, distension, absent stools, and urinary retention. Encourage hydration/fiber; consider prophylactic bowel regimen. Dose may be individualized by the care team; hold or reassess if ileus signs emerge.
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
The goal is simple: keep the pain and stomach relief you need while keeping your gut and bladder moving.
- Keep taking both as prescribed unless your prescriber tells you otherwise.
- Your care team may monitor you more closely for constipation or trouble urinating, and doses can be adjusted and individualized if needed.
- Staying well hydrated and, if your team approves, using a stool softener or fiber can help.
- Call your pharmacist or doctor if you have no bowel movement for a few days, belly swelling or pain, nausea/vomiting, or difficulty passing urine.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Dicyclomine and Acetaminophen And Codeine together?
Codeine and dicyclomine both slow the gut and bladder, so together they can worsen constipation and urinary retention and, rarely, cause a paralytic ileus. Keep taking both as prescribed, stay hydrated, and tell your care team about constipation or trouble urinating. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dicyclomine 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 Dicyclomine and Acetaminophen And Codeine interaction managed?
The goal is simple: keep the pain and stomach relief you need while keeping your gut and bladder moving. Keep taking both as prescribed unless your prescriber tells you otherwise. Your care team may monitor you more closely for constipation or trouble urinating, and doses can be adjusted and individualized if needed. Staying well hydrated and, if your team approves, using a stool softener or fiber… 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 Dicyclomine 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: 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 Dicyclomine
These medications also interact with supplements
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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