Drug interactions
Mifepristone + Norethindrone
Severity: Moderate
Mifepristone and Norethindrone: moderate 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 may modestly raise progestin levels through CYP3A4 inhibition. Its antiprogestogenic action may also oppose progestin effects and alter bleeding patterns or contraceptive reliability, and the labeled concern is mainly loss of endometrial protection.
What this interaction means in plain words
Mifepristone and Norethindrone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
CYP3A4 inhibition and pharmacodynamic antagonism at the progesterone receptor.
What to do
Use a non-hormonal backup contraceptive during mifepristone therapy. Monitor for breakthrough bleeding and reassess the hormonal regimen if it occurs.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Norethindrone?
MediHelp rates the interaction as moderate. Mifepristone and Norethindrone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Mifepristone may modestly raise progestin levels through CYP3A4 inhibition. Its antiprogestogenic action may also oppose progestin effects and alter bleeding patterns or contraceptive reliability, and the labeled concern is mainly loss of endometrial protection.
How serious is the interaction between Mifepristone and Norethindrone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-hormonal backup contraceptive during mifepristone therapy. Monitor for breakthrough bleeding and reassess the hormonal regimen if it occurs.
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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