Mifepristone and Mometasone interaction
Mifepristone and Mometasone: 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
WARNING: TERMINATION OF PREGNANCY Mifepristone is a potent antagonist of progesterone and cortisol via the progesterone and glucocorticoid (GR-II) receptors, respectively.
…ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus, due to an increased risk of adverse events. [See Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] Patients receiving systemic corticosteroids for lifesaving purposes (e.g., immunosuppression after organ transplantation) because mifepristone antagonizes the effect of glucocorticoids.
Patients receiving systemic corticosteroids for lifesaving purposes ( 4 )
For medical conditions in which chronic corticosteroid therapy is lifesaving (e.g., immunosuppression in organ transplantation), mifepristone is contraindicated. [See Contraindications (4.3)] 5.6 Use of Strong CYP3A Inhibitors Mifepristone should be used with caution in patients taking ketoconazole and other strong inhibitors of CYP3A, such as itraconazole, nefazodone,…
High doses of supplemental glucocorticoids may be needed to overcome the glucocorticoid receptor blockade produced by mifepristone.
From the Mometasone (ASMANEX HFA) label · effective 2026-07-07
Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Risk of increased systemic corticosteroid effects.
Drug Interactions with Strong Cytochrome P450 3A4 Inhibitors Caution should be exercised when considering the coadministration of ASMANEX HFA with ketoconazole, and other known strong cytochrome P450 (CYP) isoenzyme 3A4 (CYP3A4) inhibitors (e.g., ritonavir, cobicistat-containing products, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir,…
Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Use with caution.
After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally inhaled mometasone furoate increased.
Concomitant administration of CYP3A4 inhibitors may inhibit the metabolism of, and increase the systemic exposure to, mometasone furoate and potentially increase the risk for systemic corticosteroid side effects.
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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.