Interacción de Estradiol y dienogest con Fluconazol

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.

…[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 )] .