Dicyclomine and Trospium / Xanomeline: 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
Dicyclomine
Trospium / Xanomeline
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.
Both of these medicines have what we call anticholinergic effects. Dicyclomine (Bentyl) calms stomach cramps by blocking a certain nerve signal, and Cobenfy (which contains trospium) blocks that same kind of signal too. When you take them together, those effects can add up.
That means you may notice more dry mouth, constipation, blurred vision, trouble urinating, or feeling flushed. This is expected based on how the drugs work rather than from strong studies. The good news is that your care team can manage this easily by watching for these symptoms and adjusting things if needed. Please talk with your pharmacist or doctor before making any changes.
Effect: Additive antimuscarinic burden, increasing frequency and/or severity of anticholinergic adverse reactions (dry mouth, constipation, urinary retention, blurred vision, tachycardia).
- Mechanism: Pharmacodynamic (additive), not PK. Both dicyclomine and the trospium component of trospium/xanomeline are muscarinic antagonists. Neither is a prodrug relevant here.
- Direction: Increased anticholinergic effect.
- Evidence: Theoretical; severity moderate; onset unspecified.
- Management: Monitor for increased anticholinergic effects. Dose may be individualized and, if adverse effects emerge, consider dose reduction or an alternative. Use caution in elderly and those at risk for urinary retention, constipation, or narrow-angle glaucoma.
What happens
An increased risk of anticholinergic adverse reactions (eg, dry mouth, constipation)
Interaction Deep Dive
Using trospium/xanomeline together with other antimuscarinic agents that cause anticholinergic adverse reactions (for example, dry mouth and constipation) can raise how often and/or how severely these effects occur. When these drugs are given together, watch patients for a rise in the frequency and/or severity of anticholinergic adverse reactions1.
Why it happens (mechanism)
Additive antimuscarinic effects
How to manage this interaction
Here is how a care team usually handles taking these two together:
- Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may monitor you more closely for anticholinergic side effects such as dry mouth, constipation, blurred vision, or difficulty urinating.
- If side effects become bothersome, your dose may be adjusted and individualized, or an alternative may be considered.
What you can do: Stay hydrated, use fiber for constipation, and report new or worsening symptoms (especially trouble urinating) to your pharmacist or prescriber promptly.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Dicyclomine and Trospium / Xanomeline together?
Taking dicyclomine with Cobenfy (trospium/xanomeline) can add up their drying side effects like dry mouth and constipation, so keep taking both as prescribed but watch for those symptoms and tell your pharmacist or doctor if they bother you. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dicyclomine and Trospium / Xanomeline interaction?
It is rated moderate. Can be significant — usually manageable with 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 Trospium / Xanomeline interaction managed?
Here is how a care team usually handles taking these two together: Keep taking both as prescribed unless your doctor or pharmacist tells you otherwise. Your team may monitor you more closely for anticholinergic side effects such as dry mouth, constipation, blurred vision, or difficulty urinating. If side effects become bothersome, your dose may be adjusted and individualized, or an alternative may… 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 Trospium / Xanomeline 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 anything you'd monitor while I'm on both?
References (1)
- Citation #1
Keep reading about Dicyclomine
Keep reading about Trospium / Xanomeline
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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