Stribild is indicated for use as a complete regimen for the treatment of HIV 1 infection and must not be administered with other antiretroviral products.
Stribild Summary of Product Characteristics, Gilead Sciences International Ltd, November 2021.

Stribild is a complete regimen for the treatment of HIV-1 infection; therefore, Stribild should not be administered with other antiretroviral medications for treatment of HIV-1 infection.
Stribild Prescribing Information, Gilead Sciences Inc, September 2021.

Emtricitabine should not be taken with any other medicinal products containing emtricitabine.
Emtriva Summary of Product Characteristics, Gilead Sciences International Ltd, April 2019.

Healthy volunteers (n=24) received elvitegravir/ritonavir (50/100 mg once daily) with or without emtricitabine 200 mg once daily. Emtricitabine and elvitegravir/ritonavir pharmacokinetics were not significantly affected by coadministration (emtricitabine Cmax, AUC and Cmin increased by 15%, 11% and 4% respectively; elvitegravir Cmax decreased by 2%, AUC increased by 2% and Cmin increased by 14%).
Pharmacokinetics of emtricitabine, tenofovir, and GS-9137 following coadministration of emtricitabine/tenofovir disoproxil fumarate and ritonavir-boosted GS-9137. Ramanathan S, Shen G, Cheng A, Kearney BP. J Acquir Immune Defic Syndr, 2007, 45(3):274-9.