Estradiol and dienogest and Fluconazole interaction
Estradiol and dienogest and Fluconazole: 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 Estradiol and dienogest (Natazia) label · effective 2024-06-26
…[See Clinical Pharmacology (12.3).] Substances Increasing the Systemic Exposure of COCs (enzyme inhibitors): Concomitant administration of moderate or strong CYP3A4 inhibitors like azole antifungals (for example, ketoconazole, itraconazole, voriconazole, fluconazole), verapamil, macrolides (for example, clarithromycin, erythromycin), diltiazem, and grapefruit…
In a multiple dose study investigating the effect of CYP3A4 inhibitors (ketoconazole and erythromycin) on Natazia, steady state estradiol and dienogest exposures were increased when co-administered with ketoconazole or erythromycin [see Clinical Pharmacology ( 12.3 )] .
From the Fluconazole label · effective 2026-04-02
Effective contraceptive measures should be considered in women of child-bearing potential who are being treated with fluconazole 400 to 800 mg/day and should continue throughout the treatment period and for approximately 1 week (5 to 6 half-lives) after the final dose.
Oral contraceptives Two pharmacokinetic studies with a combined oral contraceptive have been performed using multiple doses of fluconazole.
There were no relevant effects on hormone level in the 50 mg fluconazole study, while at 200 mg daily, the AUCs of ethinyl estradiol and levonorgestrel were increased 40% and 24%, respectively.
Thus, multiple-dose use of fluconazole at these doses is unlikely to have an effect on the efficacy of the combined oral contraceptive.
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.