Drug interactions
Mifepristone + Rifampin
Severity: Major
Mifepristone 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 is a potent CYP3A4 inducer and is expected to markedly reduce mifepristone exposure, risking loss of efficacy. The manufacturer does not recommend coadministration with inducers.
What this interaction means in plain words
Mifepristone 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
Rifampin induces CYP3A4 (and related enzymes), greatly increasing mifepristone clearance.
What to do
Avoid the combination and use an alternative antimycobacterial or antibiotic where possible. If unavoidable, monitor clinical response closely and consider mifepristone dose adjustment.
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 Mifepristone 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 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 Rifampin?
MediHelp rates the interaction as major. Mifepristone 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 is a potent CYP3A4 inducer and is expected to markedly reduce mifepristone exposure, risking loss of efficacy. The manufacturer does not recommend coadministration with inducers.
How serious is the interaction between Mifepristone 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 an alternative antimycobacterial or antibiotic where possible. If unavoidable, monitor clinical response closely and consider mifepristone dose adjustment.
What other medicines interact with Mifepristone?
MediHelp also lists interactions of Mifepristone with, for example, Apixaban, Argatroban, Cisapride. The full list is on the Mifepristone 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.
