Drug interactions
Efavirenz + Lopinavir
Severity: Moderate
Efavirenz and Lopinavir: moderate 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 lowers lopinavir concentrations, which can reduce antiviral efficacy, and both agents carry some QT-prolonging potential. Lopinavir/ritonavir may affect efavirenz exposure as well.
What this interaction means in plain words
Efavirenz and Lopinavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Efavirenz belongs to Anti Virals; Lopinavir belongs to Anti Virals.
Why it happens
Efavirenz induces CYP3A4, lowering lopinavir levels, while both drugs may additively prolong QTc.
What to do
Increase lopinavir/ritonavir dose per labeling (e.g., 500/125 mg twice daily with tablets) when used with efavirenz. Monitor viral load and ECG in patients with QT risk factors.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Lopinavir
- Alfuzosin + Lopinavir Contraindicated
- Avanafil + Lopinavir Contraindicated
- Cisapride + Lopinavir Contraindicated
- Dronedarone + Lopinavir Contraindicated
- Eletriptan + Lopinavir Contraindicated
- Eplerenone + Lopinavir Contraindicated
Frequently asked questions
Can I take Efavirenz with Lopinavir?
MediHelp rates the interaction as moderate. Efavirenz and Lopinavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Efavirenz lowers lopinavir concentrations, which can reduce antiviral efficacy, and both agents carry some QT-prolonging potential. Lopinavir/ritonavir may affect efavirenz exposure as well.
How serious is the interaction between Efavirenz and Lopinavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Increase lopinavir/ritonavir dose per labeling (e.g., 500/125 mg twice daily with tablets) when used with efavirenz. Monitor viral load and ECG in patients with QT risk factors.
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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