Drug interactions
Efavirenz + Velpatasvir
Severity: Major
Efavirenz and Velpatasvir: major 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 reduces velpatasvir exposure, which may lead to a diminished antiviral response and hepatitis C treatment failure. Product labeling does not recommend the combination.
What this interaction means in plain words
Efavirenz and Velpatasvir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Efavirenz belongs to Anti Virals; Velpatasvir belongs to Anti Virals.
Why it happens
Efavirenz induces CYP2B6, CYP2C8 and CYP3A4, increasing velpatasvir metabolism.
What to do
Avoid the combination and change the HIV regimen to a non-inducing option before HCV treatment. Choose another HCV regimen if switching is not possible.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Velpatasvir
- Apalutamide + Velpatasvir Contraindicated
- Carbamazepine + Velpatasvir Contraindicated
- Phenytoin + Velpatasvir Contraindicated
- Bosentan + Velpatasvir Major
- Colchicine + Velpatasvir Major
- Enzalutamide + Velpatasvir Major
Frequently asked questions
Can I take Efavirenz with Velpatasvir?
MediHelp rates the interaction as major. Efavirenz and Velpatasvir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Efavirenz reduces velpatasvir exposure, which may lead to a diminished antiviral response and hepatitis C treatment failure. Product labeling does not recommend the combination.
How serious is the interaction between Efavirenz and Velpatasvir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination and change the HIV regimen to a non-inducing option before HCV treatment. Choose another HCV regimen if switching is not possible.
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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