cobicistat + atazanavir + emtricitabine + tenofovir disoproxil fumarate

**cobicistat + atazanavir + emtricitabine + tenofovir disoproxil fumarate** is an oral fixed-dose combination antiretroviral regimen for treatment of human immunodeficiency virus type 1 (HIV-1) infection. - **Atazanavir** is an HIV-1 protease inhibitor that blocks protease activity, preventing viral polyprotein cleavage and maturation. - **Cobicistat** is a pharmacokinetic enhancer (booster) that inhibits CYP3A enzymes, increasing atazanavir plasma concentrations but possesses no anti-HIV activity of its own. - **Emtricitabine** is a nucleoside reverse transcriptase inhibitor (NRTI) that interferes with viral DNA synthesis by competing with cytidine. - **Tenofovir disoproxil fumarate (TDF)** is a nucleotide reverse transcriptase inhibitor (NtRTI) that blocks reverse transcription, interfering with viral DNA chain elongation. This combination is administered orally, usually once daily, and is indicated for treatment-naive adults or as part of a combination regimen for the suppression of HIV replication[4][7][9].