Drug interactions
Darifenacin + Phenobarbital
Severity: Moderate
Darifenacin and Phenobarbital: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Phenobarbital induces CYP3A4 and can lower darifenacin concentrations, which may reduce its effectiveness.
What this interaction means in plain words
Darifenacin and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Induction of CYP3A4 by phenobarbital increases darifenacin metabolism.
What to do
Monitor for loss of symptom control and titrate darifenacin within the labeled range or choose an alternative. Reassess the dose if phenobarbital is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Darifenacin and Phenobarbital, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Darifenacin
Frequently asked questions
Can I take Darifenacin with Phenobarbital?
MediHelp rates the interaction as moderate. Darifenacin and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Phenobarbital induces CYP3A4 and can lower darifenacin concentrations, which may reduce its effectiveness.
How serious is the interaction between Darifenacin and Phenobarbital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for loss of symptom control and titrate darifenacin within the labeled range or choose an alternative. Reassess the dose if phenobarbital is stopped.
What other medicines interact with Darifenacin?
MediHelp also lists interactions of Darifenacin with, for example, Atazanavir, Bethanechol, Clarithromycin. The full list is on the Darifenacin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
