Aprepitant and Norethindrone and ethinyl estradiol interaction
Aprepitant and Norethindrone and ethinyl estradiol: 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 Norethindrone and ethinyl estradiol (Lo Loestrin Fe) label · effective 2025-03-07
Counsel patients to use a back-up method or alternative method of contraception when enzyme inducers are used with COCs ( 7.1 ) -- - ---------- ------ USE IN SPECIFIC POPULATIONS---- -- -- --------- ---- Lactation: Not recommended; Lo Loestrin Fe can decrease milk production ( 8.2 )
CYP3A4 inhibitors such as itraconazole or ketoconazole may increase plasma hormone levels.
From the Aprepitant (CINVANTI) label · effective 2026-04-01
Hormonal Contraceptives : Efficacy of contraceptives may be reduced during and for 28 days following administration of aprepitant.
Risk of Reduced Efficacy of Hormonal Contraceptives Upon coadministration with CINVANTI, the efficacy of hormonal contraceptives may be reduced during administration of and for 28 days following the last dose of CINVANTI [see Clinical Pharmacology (12.3) ] .
Hormonal Contraceptives Clinical Impact Decreased hormonal exposure during administration of and for 28 days after administration of the last dose of aprepitant [see Warnings and Precautions (5.4) , Use in Specific Populations (8.3) , and Clinical Pharmacology (12.3) ] .
Examples birth control pills, skin patches, implants, and certain IUDs CYP2C9 Substrates Warfarin Clinical Impact Decreased warfarin exposure and decreased prothrombin time (INR) [see Warnings and Precautions (5.3) , Clinical Pharmacology (12.3) ] .
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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.