Drug interactions
Darifenacin + Nortriptyline
Severity: Moderate
Darifenacin and Nortriptyline: 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
Darifenacin inhibits CYP2D6, which can raise nortriptyline levels, and both drugs have anticholinergic activity. The result may be more dry mouth, constipation, urinary retention, confusion, or tachyarrhythmia, particularly in older adults.
What this interaction means in plain words
Darifenacin and Nortriptyline 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.
Darifenacin belongs to Genitourinary; Nortriptyline belongs to Central Nervous System.
Why it happens
CYP2D6 inhibition by darifenacin reduces nortriptyline clearance, combined with additive muscarinic receptor blockade.
What to do
Monitor for anticholinergic toxicity and consider checking nortriptyline levels or an ECG if symptoms arise. Lower the nortriptyline dose if needed, and avoid the combination in frail older patients.
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 Nortriptyline, 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
Other interactions of Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Frequently asked questions
Can I take Darifenacin with Nortriptyline?
MediHelp rates the interaction as moderate. Darifenacin and Nortriptyline 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. Darifenacin inhibits CYP2D6, which can raise nortriptyline levels, and both drugs have anticholinergic activity. The result may be more dry mouth, constipation, urinary retention, confusion, or tachyarrhythmia, particularly in older adults.
How serious is the interaction between Darifenacin and Nortriptyline?
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 anticholinergic toxicity and consider checking nortriptyline levels or an ECG if symptoms arise. Lower the nortriptyline dose if needed, and avoid the combination in frail older patients.
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.
