Drug interactions
Belzutifan + Efavirenz
Severity: Moderate
Belzutifan and Efavirenz: 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
Belzutifan is a weak CYP3A4 inducer and may modestly lower efavirenz levels. Efavirenz has a long half-life and is itself an inducer, so the effect is likely small but could affect antiviral control.
What this interaction means in plain words
Belzutifan and Efavirenz 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.
Belzutifan belongs to Miscellaneous; Efavirenz belongs to Anti Virals.
Why it happens
Belzutifan induces CYP3A4 and may increase efavirenz clearance.
What to do
Monitor HIV viral load during co-therapy. Consider efavirenz plasma level monitoring if virologic response worsens.
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 Belzutifan
Frequently asked questions
Can I take Belzutifan with Efavirenz?
MediHelp rates the interaction as moderate. Belzutifan and Efavirenz 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. Belzutifan is a weak CYP3A4 inducer and may modestly lower efavirenz levels. Efavirenz has a long half-life and is itself an inducer, so the effect is likely small but could affect antiviral control.
How serious is the interaction between Belzutifan and Efavirenz?
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 HIV viral load during co-therapy. Consider efavirenz plasma level monitoring if virologic response worsens.
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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