Drug interactions
Mifepristone + Tolterodine
Severity: Major
Mifepristone and Tolterodine: major 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
Mifepristone inhibits CYP3A4 and may increase tolterodine exposure, and both agents are associated with QT prolongation. The risk is greatest with chronic mifepristone use.
What this interaction means in plain words
Mifepristone and Tolterodine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Mifepristone belongs to Endocrine; Tolterodine belongs to Genitourinary.
Why it happens
CYP3A4 inhibition by mifepristone raises tolterodine levels, with additive QT effects.
What to do
Reduce tolterodine to 1 mg twice daily (IR) or 2 mg once daily (ER) during chronic mifepristone therapy and monitor the ECG.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Tolterodine
Other interactions of Mifepristone
- Apixaban + Mifepristone Contraindicated
- Argatroban + Mifepristone Contraindicated
- Cisapride + Mifepristone Contraindicated
- Cortisone + Mifepristone Contraindicated
- Cyclosporin + Mifepristone Contraindicated
- Dabigatran etexilate + Mifepristone Contraindicated
Frequently asked questions
Can I take Mifepristone with Tolterodine?
MediHelp rates the interaction as major. Mifepristone and Tolterodine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Mifepristone inhibits CYP3A4 and may increase tolterodine exposure, and both agents are associated with QT prolongation. The risk is greatest with chronic mifepristone use.
How serious is the interaction between Mifepristone and Tolterodine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce tolterodine to 1 mg twice daily (IR) or 2 mg once daily (ER) during chronic mifepristone therapy and monitor the ECG.
What other medicines interact with Tolterodine?
MediHelp also lists interactions of Tolterodine with, for example, Clarithromycin, Clozapine, Cobicistat. The full list is on the Tolterodine page.
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