Drug interactions
Efavirenz + Exemestane
Severity: Moderate
Efavirenz and Exemestane: 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 exemestane concentrations and reduce estrogen suppression and efficacy. Labeling advises a higher exemestane dose with potent CYP3A4 inducers.
What this interaction means in plain words
Efavirenz and Exemestane 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 belongs to Anti Virals; Exemestane belongs to Oncology.
Why it happens
Efavirenz induces CYP3A4, increasing exemestane metabolism.
What to do
Increase exemestane to 50 mg daily after a meal when given with a potent inducer, and monitor clinical response.
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
Other interactions of Exemestane
Frequently asked questions
Can I take Efavirenz with Exemestane?
MediHelp rates the interaction as moderate. Efavirenz and Exemestane 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 exemestane concentrations and reduce estrogen suppression and efficacy. Labeling advises a higher exemestane dose with potent CYP3A4 inducers.
How serious is the interaction between Efavirenz and Exemestane?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Increase exemestane to 50 mg daily after a meal when given with a potent inducer, and monitor clinical response.
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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