Drug interactions
Fesoterodine + Paroxetine
Severity: Minor
Fesoterodine and Paroxetine: minor 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
Paroxetine is a strong CYP2D6 inhibitor and can raise exposure to the active metabolite of fesoterodine. Paroxetine also has anticholinergic activity, so antimuscarinic effects such as dry mouth and constipation may be additive. The pharmacokinetic effect is limited by the alternative CYP3A4 pathway.
What this interaction means in plain words
Fesoterodine and Paroxetine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Fesoterodine belongs to Genitourinary; Paroxetine belongs to Central Nervous System.
Why it happens
CYP2D6 inhibition of fesoterodine active metabolite clearance plus additive antimuscarinic effects.
What to do
Monitor for anticholinergic adverse effects after starting paroxetine. Reduce the fesoterodine dose if they become troublesome.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Fesoterodine
Other interactions of Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Fesoterodine with Paroxetine?
MediHelp rates the interaction as minor. Fesoterodine and Paroxetine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Paroxetine is a strong CYP2D6 inhibitor and can raise exposure to the active metabolite of fesoterodine. Paroxetine also has anticholinergic activity, so antimuscarinic effects such as dry mouth and constipation may be additive. The pharmacokinetic effect is limited by the alternative CYP3A4 pathway.
How serious is the interaction between Fesoterodine and Paroxetine?
MediHelp rates it minor, 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 after starting paroxetine. Reduce the fesoterodine dose if they become troublesome.
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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