Drug interactions
Idelalisib + Tolterodine
Severity: Major
Idelalisib 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
Idelalisib is a strong CYP3A inhibitor and can substantially raise tolterodine concentrations. This increases anticholinergic adverse effects and QT risk.
What this interaction means in plain words
Idelalisib 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.
Idelalisib belongs to Oncology; Tolterodine belongs to Genitourinary.
Why it happens
Strong CYP3A4 inhibition reduces tolterodine clearance.
What to do
Limit tolterodine to a maximum of 2 mg daily, or use an alternative bladder antimuscarinic not dependent on CYP3A4. Monitor for anticholinergic toxicity.
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 Idelalisib
- Alfuzosin + Idelalisib Contraindicated
- Cisapride + Idelalisib Contraindicated
- Dihydroergotamine + Idelalisib Contraindicated
- Dronedarone + Idelalisib Contraindicated
- Eletriptan + Idelalisib Contraindicated
- Eplerenone + Idelalisib Contraindicated
Frequently asked questions
Can I take Idelalisib with Tolterodine?
MediHelp rates the interaction as major. Idelalisib 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. Idelalisib is a strong CYP3A inhibitor and can substantially raise tolterodine concentrations. This increases anticholinergic adverse effects and QT risk.
How serious is the interaction between Idelalisib 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: Limit tolterodine to a maximum of 2 mg daily, or use an alternative bladder antimuscarinic not dependent on CYP3A4. Monitor for anticholinergic toxicity.
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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