darunavir + ritonavir + enfuvirtide

This is a combination regimen consisting of **darunavir**, **ritonavir**, and **enfuvirtide**, used for the treatment of HIV-1 infection, particularly in individuals with prior experience and resistance to multiple antiretroviral drug classes. Darunavir is a protease inhibitor that blocks HIV protease, an enzyme required for viral maturation. Ritonavir is another protease inhibitor primarily used in this context to inhibit CYP3A-mediated metabolism, thus boosting darunavir plasma concentrations. Enfuvirtide is a fusion inhibitor—a 36 amino acid synthetic peptide that binds to the gp41 subunit of the HIV envelope glycoprotein, preventing conformational changes necessary for the fusion of viral and cellular membranes, thereby inhibiting viral entry into host cells[1][2][4][5][6]. This regimen is used as a salvage therapy for individuals who have failed previous treatments.