Etonogestrel and ethinyl estradiol and Fosamprenavir interaction
Etonogestrel and ethinyl estradiol and Fosamprenavir: 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 Etonogestrel and ethinyl estradiol (Etonogestrel/Ethinyl Estradiol) label · effective 2025-02-26
Concomitant administration of strong or moderate CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma estrogen and/or progestin concentrations.
…non-nucleoside reverse transcriptase inhibitors Significant changes in the plasma concentrations of the estrogen and /or progestin have been noted in some cases of co-administration with HIV protease inhibitors (decrease [e.g., nelfinavir, ritonavir, darunavir/ritonavir, (fos)amprenavir/ritonavir, lopinavir/ritonavir, and tipranavir/ritonavir] or increase [e.g., indinavir…
From the Fosamprenavir (Fosamprenavir Calcium) label · effective 2026-06-30
Fosamprenavir calcium: ↓ Amprenavir ↓ Ethinyl estradiol May lead to loss of virologic response. a Fosamprenavir calcium/ritonavir: ↓ Ethinyl estradiol Increased risk of transaminase elevations.
Oral contraceptives: Ethinyl estradiol/norethindrone a Alternative methods of non-hormonal contraception are recommended.
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.