Drug interactions
Efavirenz + Lenacapavir
Severity: Major
Efavirenz and Lenacapavir: 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 may lower lenacapavir concentrations, risking reduced antiviral efficacy and development of resistance.
What this interaction means in plain words
Efavirenz and Lenacapavir 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; Lenacapavir belongs to Anti Virals.
Why it happens
Efavirenz induces CYP3A4 (and possibly P-gp/UGT), increasing lenacapavir clearance.
What to do
Avoid coadministration with efavirenz; use an alternative antiretroviral partner. Monitor viral load if exposure cannot be avoided.
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 Lenacapavir
- Apalutamide + Lenacapavir Contraindicated
- Carbamazepine + Lenacapavir Contraindicated
- Enzalutamide + Lenacapavir Contraindicated
- Flibanserin + Lenacapavir Contraindicated
- Lenacapavir + Phenytoin Contraindicated
- Lenacapavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Efavirenz with Lenacapavir?
MediHelp rates the interaction as major. Efavirenz and Lenacapavir 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 may lower lenacapavir concentrations, risking reduced antiviral efficacy and development of resistance.
How serious is the interaction between Efavirenz and Lenacapavir?
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 coadministration with efavirenz; use an alternative antiretroviral partner. Monitor viral load if exposure cannot be avoided.
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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