Drug interactions
Diltiazem + Idelalisib
Severity: Major
Diltiazem and Idelalisib: major interaction.
Last updated Sources: US FDA label
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 diltiazem concentrations. This increases the risk of bradycardia, AV block and hypotension.
What this interaction means in plain words
Diltiazem and Idelalisib 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.
Diltiazem belongs to Cardiovascular; Idelalisib belongs to Oncology.
Why it happens
Idelalisib strongly inhibits CYP3A4, reducing diltiazem clearance.
What to do
Avoid if possible, using a non-CYP3A-dependent antihypertensive or rate-control option. If combined, monitor heart rate, ECG and blood pressure and reduce the diltiazem dose.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Diltiazem and Idelalisib, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
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 Diltiazem with Idelalisib?
MediHelp rates the interaction as major. Diltiazem and Idelalisib 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 diltiazem concentrations. This increases the risk of bradycardia, AV block and hypotension.
How serious is the interaction between Diltiazem and Idelalisib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible, using a non-CYP3A-dependent antihypertensive or rate-control option. If combined, monitor heart rate, ECG and blood pressure and reduce the diltiazem dose.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
