Drug interactions
Efavirenz + Estrogens conjugated synthetic
Severity: Moderate
Efavirenz and Estrogens conjugated synthetic: 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
Efavirenz may lower estrogen concentrations through enzyme induction, potentially reducing control of vasomotor symptoms.
What this interaction means in plain words
Efavirenz and Estrogens conjugated synthetic 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
Efavirenz induces CYP3A4-mediated estrogen metabolism.
What to do
Monitor symptom relief and adjust the estrogen dose as needed.
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 Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Efavirenz with Estrogens conjugated synthetic?
MediHelp rates the interaction as moderate. Efavirenz and Estrogens conjugated synthetic 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. Efavirenz may lower estrogen concentrations through enzyme induction, potentially reducing control of vasomotor symptoms.
How serious is the interaction between Efavirenz and Estrogens conjugated synthetic?
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 relief and adjust the estrogen dose as needed.
What other medicines interact with Efavirenz?
MediHelp also lists interactions of Efavirenz with, for example, Cobimetinib, Dienogest / estradiol valerate, Dihydroergotamine intranasal. The full list is on the Efavirenz page.
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