Drug interactions
Diltiazem + Rifampin
Severity: Major
Diltiazem and Rifampin: 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
Rifampin strongly induces CYP3A4 and intestinal efflux and can markedly reduce diltiazem concentrations. This can cause loss of antihypertensive, antianginal or rate-control effect.
What this interaction means in plain words
Diltiazem and Rifampin 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.
Why it happens
Induction of CYP3A4 by rifampin increases diltiazem clearance and first-pass metabolism.
What to do
Avoid the combination and use a non-CYP3A4-dependent alternative. If it is unavoidable, monitor blood pressure and heart rate closely and adjust the diltiazem dose when rifampin is started or stopped.
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 Rifampin, 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
Frequently asked questions
Can I take Diltiazem with Rifampin?
MediHelp rates the interaction as major. Diltiazem and Rifampin 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. Rifampin strongly induces CYP3A4 and intestinal efflux and can markedly reduce diltiazem concentrations. This can cause loss of antihypertensive, antianginal or rate-control effect.
How serious is the interaction between Diltiazem and Rifampin?
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 the combination and use a non-CYP3A4-dependent alternative. If it is unavoidable, monitor blood pressure and heart rate closely and adjust the diltiazem dose when rifampin is started or stopped.
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.
