Desogestrel and ethinyl estradiol and Nirmatrelvir and ritonavir interaction
Desogestrel and ethinyl estradiol and Nirmatrelvir and ritonavir: 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 Desogestrel and ethinyl estradiol label · effective 2026-06-24
…Hepatic adenomas or carcinomas • Known or suspected pregnancy • Hypersensitivity to any component of this product • Are receiving Hepatitis C drug combinations containing ombitasvir/paritaprevir/ ritonavir, with or without dasabuvir, due to the potential for ALT elevations (see WARNINGS, Risk of Liver Enzyme Elevations with Concomitant Hepatitis C Treatment ).
Concomitant Use with HCV Combination Therapy – Liver Enzyme Elevation Do not co-administer desogestrel and ethinyl estradiol tablets with HCV drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, due to potential for ALT elevations (see WARNINGS, Risk of Liver Enzyme Elevations with Concomitant Hepatitis C Treatment).
Risk of Liver Enzyme Elevations with Concomitant Hepatitis C Treatment During clinical trials with the Hepatitis C combination drug regimen that contains ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, ALT elevations greater than 5 times the upper limit of normal (ULN), including some cases greater than 20 times the ULN, were significantly more…
…or decrease) in the plasma concentrations of 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 and atazanavir/ritonavir]) /HCV protease inhibitors…
CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations.
From the Nirmatrelvir and ritonavir (Paxlovid) label · effective 2026-02-19
Hormonal contraceptive ethinyl estradiol ↓ ethinyl estradiol An additional, non-hormonal method of contraception should be considered during the 5 days of PAXLOVID treatment and until one menstrual cycle after stopping PAXLOVID.
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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.