Drug interactions
Carbamazepine + Norethisterone
Severity: Major
Carbamazepine and Norethisterone: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Carbamazepine accelerates norethisterone clearance and can cause contraceptive failure. Breakthrough bleeding and menstrual irregularities are also more likely.
What this interaction means in plain words
Carbamazepine and Norethisterone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Carbamazepine belongs to Central Nervous System; Norethisterone belongs to Endocrine.
Why it happens
Carbamazepine induces CYP3A4 and other enzymes, increasing norethisterone metabolism.
What to do
Use a non-hormonal or enzyme-independent contraceptive such as a copper IUD or levonorgestrel IUD. If used therapeutically, monitor response and adjust the dose.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Norethisterone
- Acitretin + Norethisterone Contraindicated
- Amobarbital + Norethisterone Major
- Apalutamide + Norethisterone Major
- Belzutifan + Norethisterone Major
- Bosentan + Norethisterone Major
- Brigatinib + Norethisterone Major
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Norethisterone?
MediHelp rates the interaction as major. Carbamazepine and Norethisterone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Carbamazepine accelerates norethisterone clearance and can cause contraceptive failure. Breakthrough bleeding and menstrual irregularities are also more likely.
How serious is the interaction between Carbamazepine and Norethisterone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-hormonal or enzyme-independent contraceptive such as a copper IUD or levonorgestrel IUD. If used therapeutically, monitor response and adjust the dose.
What other medicines interact with Norethisterone?
MediHelp also lists interactions of Norethisterone with, for example, Acitretin, Amobarbital, Apalutamide. The full list is on the Norethisterone page.
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