Drug interactions
Mifepristone + Progesterone micronized
Severity: Major
Mifepristone and Progesterone micronized: 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
Mifepristone antagonizes progesterone receptors and thus blocks the intended effect of progesterone, for example endometrial protection or pregnancy support. CYP3A4 inhibition may increase progesterone exposure but does not restore receptor activity.
What this interaction means in plain words
Mifepristone and Progesterone micronized 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
Progesterone receptor antagonism by mifepristone together with CYP3A4 inhibition of progesterone metabolism.
What to do
Avoid the combination when progestogenic effect is needed, including endometrial protection in estrogen-treated women. Choose one therapy according to the clinical goal.
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 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 Progesterone micronized?
MediHelp rates the interaction as major. Mifepristone and Progesterone micronized 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. Mifepristone antagonizes progesterone receptors and thus blocks the intended effect of progesterone, for example endometrial protection or pregnancy support. CYP3A4 inhibition may increase progesterone exposure but does not restore receptor activity.
How serious is the interaction between Mifepristone and Progesterone micronized?
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 when progestogenic effect is needed, including endometrial protection in estrogen-treated women. Choose one therapy according to the clinical goal.
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.
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