Drug interactions
Fesoterodine + Quinidine
Severity: Moderate
Fesoterodine and Quinidine: 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
Quinidine is a strong CYP2D6 inhibitor and can raise exposure to the active metabolite of fesoterodine, which is partly cleared via CYP2D6. This may increase antimuscarinic adverse effects such as dry mouth and constipation.
What this interaction means in plain words
Fesoterodine and Quinidine 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; Quinidine belongs to Anti Parasitic.
Why it happens
Inhibition of CYP2D6-mediated metabolism of 5-hydroxymethyl tolterodine by quinidine.
What to do
Monitor for antimuscarinic adverse effects and tolerability. Keep fesoterodine at the lowest effective dose, and reduce it if adverse effects occur.
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 Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Fesoterodine with Quinidine?
MediHelp rates the interaction as moderate. Fesoterodine and Quinidine 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. Quinidine is a strong CYP2D6 inhibitor and can raise exposure to the active metabolite of fesoterodine, which is partly cleared via CYP2D6. This may increase antimuscarinic adverse effects such as dry mouth and constipation.
How serious is the interaction between Fesoterodine and Quinidine?
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 antimuscarinic adverse effects and tolerability. Keep fesoterodine at the lowest effective dose, and reduce it if adverse effects occur.
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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