amdoxovir + zidovudine + lopinavir + ritonavir

This drug is a fixed-dose combination of four antiretroviral agents: **amdoxovir**, **zidovudine**, **lopinavir**, and **ritonavir**. Each component has a distinct mechanism of action targeting different stages of the HIV life cycle. - **Amdoxovir** is a guanosine nucleoside analogue and a prodrug, converted in vivo to dioxolane guanosine (DXG). It inhibits HIV-1 reverse transcriptase by the incorporation of its active triphosphate metabolite into viral DNA, causing chain termination. It shows synergistic effects with zidovudine and activity against some resistant HIV strains[1][2][3]. - **Zidovudine** is a thymidine nucleoside analogue reverse transcriptase inhibitor (NRTI) that is incorporated into viral DNA, terminating synthesis. - **Lopinavir** is a protease inhibitor that blocks the HIV-1 protease enzyme, preventing cleavage of viral polyproteins and resulting in immature, non-infectious viral particles. - **Ritonavir** is a protease inhibitor primarily used at low doses as a pharmacokinetic enhancer of other protease inhibitors (notably lopinavir), via potent inhibition of cytochrome P450 3A4. This combination is indicated for the treatment of **HIV-1 infection** and is intended to provide potent, multi-mechanistic antiviral activity, reduce resistance emergence, and optimize pharmacokinetics.