Carbamazepine and Norethisterone: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Carbamazepine and Norethisterone unless specifically directed by your doctor.
How Carbamazepine interacts with Norethisterone
Carbamazepine induces CYP3A4, increasing metabolism of progestins such as norethisterone. This can reduce contraceptive efficacy and increase breakthrough bleeding.
What you should do
Use a non-enzyme-dependent contraceptive method such as copper or levonorgestrel intrauterine contraception. Counsel about reduced efficacy during and after carbamazepine exposure.
Key facts
Severity
Major — avoid combination
Mechanism
Carbamazepine induces CYP3A4, increasing metabolism of progestins such as norethisterone. This can reduce contraceptive ...
Action
Use a non-enzyme-dependent contraceptive method such as copper or levonorgestrel intrauterine contraception. Counsel abo...
Frequently asked questions
Can I take Carbamazepine and Norethisterone together?
No — this combination should generally be avoided. Use a non-enzyme-dependent contraceptive method such as copper or levonorgestrel intrauterine contraception. Counsel about reduced efficacy during and after carbamazepine exposure.
What is the severity of this interaction?
The interaction between Carbamazepine and Norethisterone is classified as Major — avoid combination. Carbamazepine induces CYP3A4, increasing metabolism of progestins such as norethisterone. This can reduce contraceptive efficacy and increase breakthrough bleeding.
What should I do if I'm prescribed both?
Use a non-enzyme-dependent contraceptive method such as copper or levonorgestrel intrauterine contraception. Counsel about reduced efficacy during and after carbamazepine exposure. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.