Carbamazepine and Estradiol and dienogest interaction
Carbamazepine and Estradiol and dienogest: 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 Carbamazepine (EQUETRO) label · effective 2025-08-19
EQUETRO can reduce the effectiveness of hormonal contraceptives.
Equetro may decrease the effectiveness of hormonal contraceptives.
EQUETRO decreases the concentrations of the following drugs through induction of their metabolism: Hormonal Contraceptives (CYP3A4 Substrates) EQUETRO is a strong inducer of CYP3A4.
EQUETRO can increase the metabolism of certain hormonal contraceptives (through CYP3A4 induction) such as oral and subdermal implant contraceptives, leading to significantly lower plasma concentrations of hormones.
This can cause contraceptive failure or breakthrough bleeding.
From the Estradiol and dienogest (Natazia) label · effective 2024-06-26
Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampin, topiramate and products containing St.
Women who take medications that are strong CYP3A4 inducers should not choose Natazia as their oral contraceptive while using these inducers and for at least 28 days after discontinuation of these inducers due to the possibility of increased breakthrough bleeding and/or decreased contraceptive efficacy.
Multiple dose co-administration of the strong CYP3A4 inducer rifampin with estradiol valerate/dienogest tablets in healthy postmenopausal women led to a decrease in dienogest and estradiol systemic exposure at steady state. [See Clinical Pharmacology (12.3).] Substances Increasing the Systemic Exposure of COCs (enzyme inhibitors): Concomitant administration of…
• CYP3A4 induction : Women taking strong CYP3A4 inducers (for example, carbamazepine, phenytoin, rifampicin, and St.
Drug Interactions Women who take medications that are strong cytochrome P450 3A4 (CYP3A4) inducers (for example, carbamazepine, phenytoin, rifampicin, and St.
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.