HAART has decreased the incidence of AIDS and death among HIV-infected individuals dramatically. This approach often becomes cumbersome to patients, involving multiple drugs administered on varying schedules. We investigated the pharmacokinetics, efficacy, and tolerability of a once-daily regimen of fosamprenavir, tenofovir, emtricitabine and ritonavir in HIV-infected treatment-naive subjects. No clinically significant interaction between the drugs was noted, and the regimen showed good efficacy and tolerability over the course of 48 weeks. © 2007 Lippincott Williams & Wilkins, Inc.