abacavir + lamivudine + zidovudine + tenofovir

This is a **four-drug combination** containing the antiretroviral agents **abacavir**, **lamivudine**, **zidovudine**, and **tenofovir**. Each is a member of the nucleoside or nucleotide reverse transcriptase inhibitor (NRTI) class, used as a component of antiretroviral therapy for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. These agents act by inhibiting HIV-1 reverse transcriptase, thereby preventing viral replication. Fixed-dose combinations containing three of these (abacavir/lamivudine/zidovudine, marketed as Trizivir) are clinically available and approved for use in adults and adolescents with HIV; however, a fixed-dose combination or branded product containing all four drugs together does not appear to be currently marketed or formally approved. Clinical guidance on concurrent use of all four agents is limited, and such a regimen would only be considered in very select circumstances, as triple or dual NRTI combinations are generally the recommended standard due to overlapping toxicity and resistance concerns. Each individual component is widely used in HIV therapy as part of combination regimens[1][2][3][4][5][6].