Drug interactions
Rifampin + Ulipristal
Severity: Major
Rifampin and Ulipristal: 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
Rifampin is a potent CYP3A4 inducer and substantially lowers ulipristal exposure, which can cause emergency contraception to fail.
What this interaction means in plain words
Rifampin and Ulipristal 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 strongly induces CYP3A4, increasing ulipristal metabolism.
What to do
Avoid ulipristal and use a copper intrauterine device. Induction persists for about two weeks after stopping rifampin.
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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Frequently asked questions
Can I take Rifampin with Ulipristal?
MediHelp rates the interaction as major. Rifampin and Ulipristal 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 substantially lowers ulipristal exposure, which can cause emergency contraception to fail.
How serious is the interaction between Rifampin and Ulipristal?
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 ulipristal and use a copper intrauterine device. Induction persists for about two weeks after stopping rifampin.
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