Atazanavir and Mifepristone interaction
Atazanavir and Mifepristone: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Atazanavir (REYATAZ) label · effective 2024-12-05
Hormonal contraceptives: ethinyl estradiol and norgestimate or norethindrone ↓ ethinyl estradiol ↑ norgestimate c ↑ ethinyl estradiol ↑ norethindrone d Use caution if considering coadministration of oral contraceptives with REYATAZ or REYATAZ with ritonavir.
Potential for REYATAZ to Affect Other Drugs Atazanavir is an inhibitor of CYP3A and UGT1A1.
If REYATAZ with ritonavir is coadministered with an oral contraceptive, it is recommended that the oral contraceptive contain at least 35 mcg of ethinyl estradiol.
If REYATAZ is administered without ritonavir, the oral contraceptive should contain no more than 30 mcg of ethinyl estradiol.
Coadministration of REYATAZ or REYATAZ with ritonavir and other hormonal contraceptives (eg, contraceptive patch, contraceptive vaginal ring, or injectable contraceptives) or oral contraceptives containing progestogens other than norethindrone or norgestimate, or less than 25 mcg of ethinyl estradiol, has not been studied; therefore, alternative methods of contraception…
From the Mifepristone label · effective 2025-09-25
…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, ritonavir, nelfinavir, indinavir, atazanavir, amprenavir, fosamprenavir, clarithromycin, conivaptan, lopinavir/ritonavir, posaconazole,…
Ketoconazole and other strong inhibitors of CYP3A, such as itraconazole, nefazodone, ritonavir, nelfinavir, indinavir, atazanavir, amprenavir and fosamprenavir, clarithromycin, conivaptan, lopinavir /ritonavir, posaconazole, saquinavir, telithromycin, or voriconazole may increase exposure to mifepristone.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.