Drug interactions
Amitriptyline + Fesoterodine
Severity: Moderate
Amitriptyline and Fesoterodine: 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
Both drugs have antimuscarinic activity, so combining them can intensify dry mouth, constipation, blurred vision, urinary retention and confusion. Older patients and those with cognitive impairment or narrow-angle glaucoma are at higher risk. Amitriptyline also has CYP2D6-related variability that may add to exposure.
What this interaction means in plain words
Amitriptyline and Fesoterodine 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.
Amitriptyline belongs to Central Nervous System; Fesoterodine belongs to Genitourinary.
Why it happens
Additive antimuscarinic (anticholinergic) pharmacodynamic effects.
What to do
Monitor for anticholinergic adverse effects such as urinary retention, constipation and cognitive changes, particularly in older adults. Consider a lower-anticholinergic antidepressant or reduce doses if symptoms develop.
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?
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Other interactions of Fesoterodine
Other interactions of Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with Fesoterodine?
MediHelp rates the interaction as moderate. Amitriptyline and Fesoterodine 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. Both drugs have antimuscarinic activity, so combining them can intensify dry mouth, constipation, blurred vision, urinary retention and confusion. Older patients and those with cognitive impairment or narrow-angle glaucoma are at higher risk. Amitriptyline also has CYP2D6-related variability that may add to exposure.
How serious is the interaction between Amitriptyline and Fesoterodine?
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 adverse effects such as urinary retention, constipation and cognitive changes, particularly in older adults. Consider a lower-anticholinergic antidepressant or reduce doses if symptoms develop.
What other medicines interact with Fesoterodine?
MediHelp also lists interactions of Fesoterodine with, for example, Bethanechol, Clozapine, Levoketoconazole. The full list is on the Fesoterodine page.
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