Efavirenz, lamivudine, and tenofovir and Lopinavir and ritonavir interaction
Efavirenz, lamivudine, and tenofovir and Lopinavir and ritonavir: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Lopinavir and ritonavir (Kaletra) label · effective 2026-07-23
KALETRA once daily in combination with efavirenz or nevirapine is not recommended [see Dosage and Administration ( 2 )] .
Non-nucleoside Reverse Transcriptase Inhibitors: efavirenz*, nevirapine* ↓ lopinavir Increase the dose of KALETRA tablets to 500/125 mg when KALETRA tablet is co-administered with efavirenz or nevirapine.
Nucleoside Reverse Transcriptase Inhibitor: tenofovir disoproxil fumarate* ↑ tenofovir Patients receiving KALETRA and tenofovir should be monitored for adverse reactions associated with tenofovir.
Potential for KALETRA to Affect Other Drugs Lopinavir/ritonavir is an inhibitor of CYP3A and may increase plasma concentrations of agents that are primarily metabolized by CYP3A.
Although not observed in the KALETRA/ketoconazole drug interaction study, co-administration of KALETRA and other drugs that inhibit CYP3A may increase lopinavir plasma concentrations.
From the Efavirenz, lamivudine, and tenofovir (SYMFI) label · effective 2019-10-15
Lactic Acidosis and Severe Hepatomegaly with Steatosis Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs and other antiretrovirals.
• SYMFI should not be administered with other antiretroviral medications for the treatment of HIV-1 infection.
Not Recommended with Other Antiretroviral Medications SYMFI is a complete regimen for the treatment of HIV-1 infection; therefore, it should not be administered with other antiretroviral medications for treatment of HIV-1 infection.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.