Drug interactions
Efavirenz + Sofosbuvir-velpatasvir
Severity: Major
Efavirenz and Sofosbuvir-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 induces CYP2B6 and CYP3A4 and lowers velpatasvir exposure. This can reduce the likelihood of HCV cure. Coadministration is not recommended in labeling.
What this interaction means in plain words
Efavirenz and Sofosbuvir-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; Sofosbuvir-velpatasvir belongs to Anti Virals.
Why it happens
Efavirenz induces CYP2B6, CYP3A4 and CYP2C8, increasing velpatasvir metabolism.
What to do
Avoid the combination in HIV/HCV coinfection and switch to a non-inducing antiretroviral such as an integrase inhibitor regimen. Consult an HIV specialist before changing therapy.
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 Sofosbuvir-velpatasvir
- Rifampin + Sofosbuvir-velpatasvir Contraindicated
- Rifapentine + Sofosbuvir-velpatasvir Contraindicated
- Sofosbuvir-velpatasvir + St john's wort Contraindicated
- Amiodarone + Sofosbuvir-velpatasvir Major
- Apalutamide + Sofosbuvir-velpatasvir Major
- Carbamazepine + Sofosbuvir-velpatasvir Major
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 Sofosbuvir-velpatasvir?
MediHelp rates the interaction as major. Efavirenz and Sofosbuvir-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 induces CYP2B6 and CYP3A4 and lowers velpatasvir exposure. This can reduce the likelihood of HCV cure. Coadministration is not recommended in labeling.
How serious is the interaction between Efavirenz and Sofosbuvir-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 in HIV/HCV coinfection and switch to a non-inducing antiretroviral such as an integrase inhibitor regimen. Consult an HIV specialist before changing therapy.
What other medicines interact with Sofosbuvir-velpatasvir?
MediHelp also lists interactions of Sofosbuvir-velpatasvir with, for example, Rifampin, Rifapentine, St john's wort. The full list is on the Sofosbuvir-velpatasvir page.
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