Drug interactions
Efavirenz + Indinavir
Severity: Major
Efavirenz and Indinavir: 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 indinavir concentrations, which may cause virologic failure and resistance if the dose is not adjusted. Unboosted indinavir is particularly affected.
What this interaction means in plain words
Efavirenz and Indinavir 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.
Why it happens
Efavirenz induces CYP3A4, increasing indinavir clearance.
What to do
Increase the indinavir dose or preferably use ritonavir-boosted indinavir, and monitor HIV RNA. Consider an alternative regimen.
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
Frequently asked questions
Can I take Efavirenz with Indinavir?
MediHelp rates the interaction as major. Efavirenz and Indinavir 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 indinavir concentrations, which may cause virologic failure and resistance if the dose is not adjusted. Unboosted indinavir is particularly affected.
How serious is the interaction between Efavirenz and Indinavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Increase the indinavir dose or preferably use ritonavir-boosted indinavir, and monitor HIV RNA. Consider an alternative regimen.
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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