Skip to content

Drug interactions

Efavirenz + Elvitegravir

Severity: Major

Efavirenz and Elvitegravir: 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 metabolic enzymes and can lower elvitegravir exposure when elvitegravir is boosted regimens are used. Reduced concentrations risk virologic failure and development of resistance.

What this interaction means in plain words

Efavirenz and Elvitegravir 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.

Evidence level: Moderate

Why it happens

Efavirenz induces CYP3A4 and UGT1A1, increasing the clearance of elvitegravir and of its pharmacokinetic booster.

What to do

Avoid combining efavirenz with elvitegravir-containing regimens and select an alternative antiretroviral combination. If used together, check HIV RNA closely.

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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

Pro+ members

Unlock the full page

Create an account and start a Pro+ trial to unlock the full management advice for Efavirenz and Elvitegravir, the additional notes, the evidence detail and the whole-prescription interaction checker.

  • Full clinical management advice
  • Additional notes
  • Evidence detail
  • Interaction checker for a whole prescription

Try Pro+ free for 14 days on the web. No card needed.

Frequently asked questions

Can I take Efavirenz with Elvitegravir?

MediHelp rates the interaction as major. Efavirenz and Elvitegravir 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 metabolic enzymes and can lower elvitegravir exposure when elvitegravir is boosted regimens are used. Reduced concentrations risk virologic failure and development of resistance.

How serious is the interaction between Efavirenz and Elvitegravir?

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 combining efavirenz with elvitegravir-containing regimens and select an alternative antiretroviral combination. If used together, check HIV RNA closely.

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.

Full monographs, dosing and an interaction checker in the MediHelp app

Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.

Browse A–Z · Drug interactions

Get the app Sign in