Conjugated estrogens and bazedoxifene and Mifepristone interaction
Conjugated estrogens and bazedoxifene and Mifepristone: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Mifepristone label · effective 2025-09-25
Hormonal contraceptives: Do not use with mifepristone ( 7.6 ).
…study has been conducted to evaluate the effect of mifepristone on substrates of CYP2B6, the concomitant use of bupropion and efavirenz should be undertaken with caution. [See Clinical Pharmacology ( 12.3 )] 7.6 Use of Hormonal Contraceptives Mifepristone is a progesterone-receptor antagonist and will interfere with the effectiveness of hormonal contraceptives.
Therefore, non-hormonal contraceptive methods should be used. [See Use In Specific Populations ( 8.3 )]
From the Conjugated estrogens and bazedoxifene (Duavee) label · effective 2026-07-31
• Women taking DUAVEE should not take progestins, additional estrogens or additional estrogen agonist/antagonists ( 5.1 )
The relative risk associated with combined current and recent use (discontinued use within 5 years before cancer diagnosis) was 1.37 (95% CI 1.27–1.48), and the elevated risk was significant for both estrogen-alone and estrogen plus progestin products.
Concomitant administration of itraconazole, a strong CYP3A4 inhibitor, with DUAVEE, resulted in increases in bazedoxifene exposure (40%) and, to a lesser extent, conjugated estrogens exposure (9% for baseline-adjusted total estrone, 5% for total equilin), compared to DUAVEE alone [see Pharmacokinetics (12.3) ] .
Drugs Containing Progestins, Estrogens or Estrogen Agonist/Antagonists DUAVEE contains conjugated estrogens and bazedoxifene, an estrogen agonist/antagonist.
Women taking DUAVEE should not take progestins, additional estrogens or additional estrogen agonist/antagonists.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.