Atazanavir (ATV), a recently approved PI, appears to have little to no impact on the lipid profile in subjects enrolled in clinical trials. Other advantages with atazanavir are its dosing schedule and overall tolerability. Furthermore, recent studies using ritonavir-boosted ATV also show favorable lipid effects compared to LPV/r. Ritonavir boosting provides higher drug levels and therefore may improve the potency of ATV, especially against PI-resistant virus.