Carbamazepine and Ethinylestradiol: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Carbamazepine and Ethinylestradiol unless specifically directed by your doctor.
How Carbamazepine interacts with Ethinylestradiol
Carbamazepine is a strong inducer of CYP3A4 and UGT enzymes, accelerating metabolism of ethinylestradiol and reducing contraceptive efficacy with risk of unintended pregnancy.
What you should do
Recommend a non-hormonal contraceptive method (copper IUD or depot medroxyprogesterone) during and for 4 weeks after carbamazepine therapy.
Key facts
Severity
Major — avoid combination
Mechanism
Carbamazepine is a strong inducer of CYP3A4 and UGT enzymes, accelerating metabolism of ethinylestradiol and reducing co...
Action
Recommend a non-hormonal contraceptive method (copper IUD or depot medroxyprogesterone) during and for 4 weeks after car...
Frequently asked questions
Can I take Carbamazepine and Ethinylestradiol together?
No — this combination should generally be avoided. Recommend a non-hormonal contraceptive method (copper IUD or depot medroxyprogesterone) during and for 4 weeks after carbamazepine therapy.
What is the severity of this interaction?
The interaction between Carbamazepine and Ethinylestradiol is classified as Major — avoid combination. Carbamazepine is a strong inducer of CYP3A4 and UGT enzymes, accelerating metabolism of ethinylestradiol and reducing contraceptive efficacy with risk of unintended pregnancy.
What should I do if I'm prescribed both?
Recommend a non-hormonal contraceptive method (copper IUD or depot medroxyprogesterone) during and for 4 weeks after carbamazepine therapy. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.