Used in the treatment of HIV-1 infection, Atazanavir is an antiretroviral medication that belongs to the protease inhibitor class. It works by blocking the activity of the HIV protease enzyme, preventing the virus from maturing and producing infectious particles. Typically prescribed as part of a combination therapy regimen, it helps reduce viral load and increase CD4 cell count, improving immune function. Its once-daily dosing and relatively favorable lipid profile compared to other protease inhibitors make it a preferred option in some patients. It is often co-administered with a low dose of ritonavir or cobicistat to boost its effectiveness through pharmacokinetic enhancement.