Efavirenz or Atazanavir/Ritonavir Given With Emtricitabine/Tenofovir Disoproxil Fumarate or Abacavir/Lamivudine in HIV Infected Treatment-Naive Adults

Currently, the preferred anti-HIV regimens used in the United States consist of two nucleoside reverse transcriptase inhibitors (NRTIs) and the nonnucleoside reverse transcriptase inhibitor (NNRTI) efavirenz (EFV). However, with new anti-HIV drugs being approved, alternative regimens need to be tested to determine if new drug combinations have increased effectiveness in treating HIV. The purpose of this study is to test the safety, tolerability, and effectiveness of four different regimens in HIV-infected adults who have never taken anti-HIV drugs.