lamivudine + abacavir + amprenavir + ritonavir

This drug is a **combination antiretroviral therapy** consisting of four agents: lamivudine, abacavir, amprenavir, and ritonavir. All four are used for the treatment of **human immunodeficiency virus (HIV)** infection, typically in advanced or treatment-experienced cases. - **Lamivudine** and **abacavir** are **nucleoside reverse transcriptase inhibitors (NRTIs)**; they inhibit HIV reverse transcriptase enzyme by incorporation into viral DNA, causing chain termination and stopping DNA elongation[2][4]. - **Amprenavir** is a **HIV-1 protease inhibitor**, binding to the active site of the HIV-1 protease and preventing the proteolytic processing of viral polyprotein precursors, resulting in non-infectious viral particles[6][8]. - **Ritonavir** is another **protease inhibitor** but is chiefly used to boost the levels of other protease inhibitors by inhibiting their metabolism (CYP3A4)[8][6]. This four-drug combination is not a single branded tablet formulation but is sometimes used in clinical settings, particularly pediatric or heavily treatment-experienced patients, as fixed- or co-administered dose combinations[1]. The combination provides a multi-mechanistic approach, targeting both reverse transcriptase and protease, two essential HIV enzymes.