Drug interactions
Aprepitant + Tolterodine
Severity: Moderate
Aprepitant and Tolterodine: 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
Tolterodine is metabolized by CYP2D6 and, in poor metabolizers, by CYP3A4. Aprepitant may raise tolterodine levels, mainly relevant in CYP2D6 poor metabolizers, raising the risk of anticholinergic effects and QT effects.
What this interaction means in plain words
Aprepitant and Tolterodine 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.
Aprepitant belongs to Gastrointestinal Tract; Tolterodine belongs to Genitourinary.
Why it happens
Aprepitant inhibits CYP3A4, reducing the alternate metabolic pathway of tolterodine.
What to do
Monitor for anticholinergic effects such as dry mouth, urinary retention and palpitations. Consider a tolterodine dose reduction in known CYP2D6 poor metabolizers.
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 Aprepitant
- Aprepitant + Lomitapide Contraindicated
- Aprepitant + Pimozide Contraindicated
- Aprepitant + Avapritinib Major
- Aprepitant + Bosutinib Major
- Aprepitant + Carbamazepine Major
- Aprepitant + Cobicistat Major
Other interactions of Tolterodine
Frequently asked questions
Can I take Aprepitant with Tolterodine?
MediHelp rates the interaction as moderate. Aprepitant and Tolterodine 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. Tolterodine is metabolized by CYP2D6 and, in poor metabolizers, by CYP3A4. Aprepitant may raise tolterodine levels, mainly relevant in CYP2D6 poor metabolizers, raising the risk of anticholinergic effects and QT effects.
How serious is the interaction between Aprepitant and Tolterodine?
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 effects such as dry mouth, urinary retention and palpitations. Consider a tolterodine dose reduction in known CYP2D6 poor metabolizers.
What other medicines interact with Aprepitant?
MediHelp also lists interactions of Aprepitant with, for example, Lomitapide, Pimozide, Avapritinib. The full list is on the Aprepitant page.
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