Antiviral activity and clinical efficacy of atazanavir in HIV-1-infected patients: a review.

Antiretroviral regimens based on human immunodeficiency virus-1 (HIV-1) protease inhibitors (PIs) are hampered by a number of side effects, mainly diarrhea, dyslipidemia, an increased risk of cardiovascular events and diabetes, and lipoaccumulation in the neck and abdomen. Although challenged by these potential untoward effects, PIs are still the cornerstone of highly active antiretroviral therapy (HAART) because of their potency and high genetic barrier. Atazanavir (ATV) is the first once-daily azapeptide HIV-1 PI and can be boosted by ritonavir. The efficacy of ritonavir-boosted ATV (ATV/r)-containing regimens in patients harboring drug-resistant variants is not statistically different from that of the reference PI lopinavir/ritonavir. In Italy, ATV, either boosted or unboosted, is licensed only for drug-experienced patients. However, in clinical trials ATV/r has proved to be effective in treatment-naive HIV-1-infected individuals. There is no evidence that ATV/r-based regimens lead to the selection of mutations conferring cross-resistance to other PIs, and this drug combination has now been included among those recommended by the International AIDS Society-USA Panel and the Department of Health and Human Services (DHHS) Panel as initial treatment when a boosted-PI-based regimen is preferred to a NNRTI-based regimen.