Efavirenz, lamivudine, and tenofovir and Emtricitabine interaction
Efavirenz, lamivudine, and tenofovir and Emtricitabine: 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 Emtricitabine (Emtriva) label · effective 2025-12-02
Lactic Acidosis/Severe Hepatomegaly with Steatosis Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including FTC, alone or in combination with other antiretrovirals.
The potential for drug interactions with EMTRIVA has been studied in combination with AZT, indinavir, d4T, famciclovir, and tenofovir DF (TDF).
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.