saquinavir + lopinavir + ritonavir + nucleoside reverse-transcriptase inhibitors

This is a combination antiretroviral regimen consisting of **saquinavir**, **lopinavir**, **ritonavir**, and one or more **nucleoside reverse-transcriptase inhibitors (NRTIs)**. Saquinavir, lopinavir, and ritonavir are all **HIV-1 protease inhibitors**, with ritonavir primarily used to boost the plasma levels of other protease inhibitors by inhibiting their metabolism via CYP3A. NRTIs, meanwhile, inhibit reverse transcriptase by causing DNA chain termination during viral replication. This regimen is used in the treatment of **HIV-1 infection** to suppress viral replication and improve immune function. Ritonavir-boosted protease inhibitor combinations are a cornerstone of highly active antiretroviral therapy (HAART). This combination is not marketed as a single formulation but is used as a regimen of separate agents in clinical practice[1][2][3][4][5].