Drug interactions
Carbamazepine + Conjugated estrogens
Severity: Moderate
Carbamazepine and Conjugated estrogens: moderate 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 can lower systemic estrogen levels, reducing efficacy for menopausal symptoms. Loss of endometrial protection and breakthrough bleeding may occur.
What this interaction means in plain words
Carbamazepine and Conjugated estrogens can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Induction of CYP3A4 increases hepatic and intestinal metabolism of estrogens.
What to do
Monitor symptom control and bleeding patterns and increase the estrogen dose if needed. Consider a non-inducing anticonvulsant.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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
Frequently asked questions
Can I take Carbamazepine with Conjugated estrogens?
MediHelp rates the interaction as moderate. Carbamazepine and Conjugated estrogens can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Carbamazepine can lower systemic estrogen levels, reducing efficacy for menopausal symptoms. Loss of endometrial protection and breakthrough bleeding may occur.
How serious is the interaction between Carbamazepine and Conjugated estrogens?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor symptom control and bleeding patterns and increase the estrogen dose if needed. Consider a non-inducing anticonvulsant.
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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