Drug interactions
Fesoterodine + Perphenazine
Severity: Moderate
Fesoterodine and Perphenazine: 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
Perphenazine has some anticholinergic activity and may add to fesoterodine's antimuscarinic effects, causing dry mouth, constipation, urinary retention and confusion. Fesoterodine may also increase perphenazine exposure indirectly, since perphenazine is a CYP2D6 substrate, but this is not well established.
What this interaction means in plain words
Fesoterodine and Perphenazine 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.
Fesoterodine belongs to Genitourinary; Perphenazine belongs to Central Nervous System.
Why it happens
Additive antimuscarinic pharmacodynamic effects.
What to do
Monitor for anticholinergic adverse effects and cognitive change, especially in older adults. Use the lowest effective doses of each.
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 Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Fesoterodine with Perphenazine?
MediHelp rates the interaction as moderate. Fesoterodine and Perphenazine 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. Perphenazine has some anticholinergic activity and may add to fesoterodine's antimuscarinic effects, causing dry mouth, constipation, urinary retention and confusion. Fesoterodine may also increase perphenazine exposure indirectly, since perphenazine is a CYP2D6 substrate, but this is not well established.
How serious is the interaction between Fesoterodine and Perphenazine?
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 and cognitive change, especially in older adults. Use the lowest effective doses of each.
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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