Monotherapy Versus Placebo Over 7 Days-Non-Nucleoside Reverse Transcriptase Inhibitor-Experienced HIV1 Infected Adults

Inclusion criteria: * CD4 cell count greater than or equal to 200 cells/mm3. * HIV-1 RNA \>2000 copies/mL. * Must have history of NNRTI treatment with subsequent failure and documented evidence of an NNRTI-associated mutation or a phenotype displaying reduced activity to efavirenz, nevirapine or delavirdine. * Normal resting 12-lead electrocardiogram. Exclusion criteria: * Any history of seizure, CNS toxoplasmosis infection, or any CNS (central nervous system) lesion. * Chronic diarrhea (\>3 loose stools/day). * An active CDC Category C disease (1993), except cutaneous Kaposi's Sarcoma (KS) not requiring systemic therapy during the trial. * Less than 4 weeks since stopping anti-retroviral therapy (ART) therapy prior to Day 1. * Any acute laboratory abnormality. * Positive for HCV antibody or HepBsAG. * Active infections requiring therapy in the previous 4 weeks.