Drug interactions
Carbamazepine + Norgestrel
Severity: Major
Carbamazepine and Norgestrel: 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 reduces norgestrel exposure, which can lead to ovulation and unintended pregnancy. Breakthrough bleeding may also occur.
What this interaction means in plain words
Carbamazepine and Norgestrel 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; Norgestrel belongs to Endocrine.
Why it happens
Carbamazepine induces CYP3A4, increasing hepatic metabolism of norgestrel.
What to do
Switch to an alternative contraceptive such as an intrauterine device or injectable medroxyprogesterone. If norgestrel is continued, add a barrier method and continue it for 28 days after stopping carbamazepine.
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 Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Other interactions of Norgestrel
- Amobarbital + Norgestrel Major
- Apalutamide + Norgestrel Major
- Bosentan + Norgestrel Major
- Efavirenz + Norgestrel Major
- Enzalutamide + Norgestrel Major
- Eslicarbazepine + Norgestrel Major
Frequently asked questions
Can I take Carbamazepine with Norgestrel?
MediHelp rates the interaction as major. Carbamazepine and Norgestrel 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 reduces norgestrel exposure, which can lead to ovulation and unintended pregnancy. Breakthrough bleeding may also occur.
How serious is the interaction between Carbamazepine and Norgestrel?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Switch to an alternative contraceptive such as an intrauterine device or injectable medroxyprogesterone. If norgestrel is continued, add a barrier method and continue it for 28 days after stopping carbamazepine.
What other medicines interact with Carbamazepine?
MediHelp also lists interactions of Carbamazepine with, for example, Artemether / lumefantrine, Cabotegravir, Delamanid. The full list is on the Carbamazepine page.
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