Aclidinium and Buprenorphine: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Aclidinium
Buprenorphine
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 two medicines that can both slow down your gut and bladder. Buprenorphine is an opioid, and opioids are well known for causing constipation. Aclidinium (Tudorza) is an inhaler for COPD, and it belongs to a group of drugs that can also slow the gut and make it harder to empty your bladder.
Used together, these effects can add up. In rare cases, that could lead to severe constipation where the bowel nearly stops moving, or trouble urinating. This concern is mostly theoretical, so please don't worry, but it's worth knowing. Keep taking both as prescribed, and let your care team know if you notice these symptoms.
Effect: Additive risk of reduced GI motility (severe constipation, potential paralytic ileus) and urinary retention.
Mechanism: Pharmacodynamic additive effect. Buprenorphine (mu-opioid agonist) reduces GI motility; aclidinium is an inhaled long-acting muscarinic antagonist with anticholinergic effects on smooth muscle and bladder.
- Direction: Additive PD effect, no PK/enzyme interaction.
- Severity/Evidence: Rated major but theoretical; systemic anticholinergic exposure from inhaled aclidinium is low.
- Onset: Unspecified.
- Management: Monitor for constipation, abdominal distension, and urinary retention. Consider prophylactic bowel regimen if opioid-related constipation emerges.
What happens
An increased risk of paralytic ileus
Interaction Deep Dive
When buprenorphine is given together with an anticholinergic agent, the combination can lead to urinary retention or severe constipation that progresses to paralytic ileus. Patients receiving buprenorphine 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
Good news: this is usually manageable, and you should keep taking both medicines as prescribed unless your prescriber tells you otherwise.
- Watch for warning signs: no bowel movement for several days, a swollen or painful belly, nausea or vomiting, or trouble passing urine.
- Report early: tell your pharmacist or doctor if you notice constipation or bladder trouble so it can be addressed before it worsens.
- Your care team may monitor you more closely and can suggest options to keep your bowels moving.
Seek prompt care if you can't have a bowel movement or can't urinate.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Aclidinium and Buprenorphine together?
Both drugs can slow your gut and bladder, so together they raise the chance of severe constipation or urinary retention. Keep taking both as prescribed, watch for these symptoms, and tell your care team if they appear. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Aclidinium and Buprenorphine 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 Aclidinium and Buprenorphine interaction managed?
Good news: this is usually manageable, and you should keep taking both medicines as prescribed unless your prescriber tells you otherwise. Watch for warning signs: no bowel movement for several days, a swollen or painful belly, nausea or vomiting, or trouble passing urine. Report early: tell your pharmacist or doctor if you notice constipation or bladder trouble so it can be addressed before it wo… 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 Aclidinium or Buprenorphine 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: BRIXADI(TM) subcutaneous extended-release injection, buprenorphine subcutaneous extended-release injection. Braeburn Inc (per FDA), Plymouth Meeting, PA, 2023. DailyMed
Keep reading about Aclidinium
Keep reading about Buprenorphine
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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