Atazanavir and Estradiol interaction
Atazanavir and Estradiol: 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.
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 Estradiol (Delestrogen) label · effective 2026-05-13
Inhibitors of CYP3A4 such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice may increase plasma concentrations of estrogens and may result in side effects.
Therefore, inducers or inhibitors of CYP3A4 may affect estrogen drug metabolism.
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.