Drug interactions
Carbamazepine + Etonogestrel
Severity: Major
Carbamazepine and Etonogestrel: 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 lowers etonogestrel concentrations and can cause contraceptive failure with the implant or vaginal ring.
What this interaction means in plain words
Carbamazepine and Etonogestrel 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; Etonogestrel belongs to Endocrine.
Why it happens
Carbamazepine induces CYP3A4, which increases the metabolism of etonogestrel.
What to do
Use a non-hormonal or non-inducer-sensitive method such as a copper or levonorgestrel intrauterine device. If the hormonal method is continued, add a barrier method and stay alert to pregnancy risk.
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 Etonogestrel
Frequently asked questions
Can I take Carbamazepine with Etonogestrel?
MediHelp rates the interaction as major. Carbamazepine and Etonogestrel 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 lowers etonogestrel concentrations and can cause contraceptive failure with the implant or vaginal ring.
How serious is the interaction between Carbamazepine and Etonogestrel?
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 non-inducer-sensitive method such as a copper or levonorgestrel intrauterine device. If the hormonal method is continued, add a barrier method and stay alert to pregnancy risk.
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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