Efavirenz and Emtricitabine, rilpivirine, and tenofovir interaction
Efavirenz and Emtricitabine, rilpivirine, and tenofovir: 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 Efavirenz label · effective 2024-03-31
Not recommended with ATRIPLA, which contains efavirenz, emtricitabine, and tenofovir disoproxil fumarate, unless needed for dose adjustment when coadministered with rifampin.
Coadministration with Related Products Coadministration of efavirenz with ATRIPLA (efavirenz 600 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) is not recommended unless needed for dose adjustment (e.g., with rifampin), since efavirenz is one of its active ingredients.
…Efavirenz No dosage adjustment is recommended when efavirenz is given with the following: aluminum/magnesium hydroxide antacids, azithromycin, cetirizine, famotidine, fluconazole, lorazepam, nelfinavir, nucleoside reverse transcriptase inhibitors (abacavir, emtricitabine, lamivudine, stavudine, tenofovir disoproxil fumarate, zidovudine), paroxetine, and raltegravir.
From the Emtricitabine, rilpivirine, and tenofovir (COMPLERA) label · effective 2025-07-16
COMPLERA is a complete regimen for the treatment of HIV-1 infection; therefore, coadministration with other antiretroviral medications for treatment of HIV-1 infection is not recommended.
Not Recommended with Other Antiretroviral Medications Because COMPLERA is a complete regimen, coadministration with other antiretroviral medications for the treatment of HIV-1 infection is not recommended.
Drugs Inducing or Inhibiting CYP3A Enzymes Rilpivirine is primarily metabolized by cytochrome P450 (CYP) 3A, and drugs that induce or inhibit CYP3A may thus affect the clearance of RPV [see Contraindications (4) , Warnings and Precautions (5.7) , and Clinical Pharmacology (12.3) ] .
Coadministration of RPV and drugs that induce CYP3A may result in decreased plasma concentrations of RPV and loss of virologic response and possible resistance to RPV or to the class of NNRTIs.
Coadministration of RPV and drugs that inhibit CYP3A may result in increased plasma concentrations of RPV.
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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.