Drug interactions
Efavirenz + Nefazodone
Severity: Moderate
Efavirenz and Nefazodone: 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 reduce nefazodone and its active metabolite concentrations, potentially causing loss of antidepressant effect. Nefazodone can also inhibit CYP3A4 and affect efavirenz exposure.
What this interaction means in plain words
Efavirenz and Nefazodone 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, increasing nefazodone clearance.
What to do
Monitor depressive symptoms and consider an alternative antidepressant with fewer CYP interactions.
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 Nefazodone?
MediHelp rates the interaction as moderate. Efavirenz and Nefazodone 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 reduce nefazodone and its active metabolite concentrations, potentially causing loss of antidepressant effect. Nefazodone can also inhibit CYP3A4 and affect efavirenz exposure.
How serious is the interaction between Efavirenz and Nefazodone?
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 depressive symptoms and consider an alternative antidepressant with fewer CYP interactions.
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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