A Study of Two Anti-HIV Drug Combinations

Inclusion Criteria Patients must have: * HIV infection documented by a licensed antibody ELISA assay and confirmed by Western blot, positive HIV blood culture, positive HIV serum antigen, or plasma viremia. * CD4+ cell count of at least 300 cells/mm3. * HIV-1 RNA less than 10,000 copies/ml by Roche Amplicor PCR assay. * CDC Category A or B Classification for HIV infection (no clinical diagnosis of AIDS). * Compliance with dosing schedule and protocol evaluations. Prior Medication: Required: * 3TC at 150 mg bid, ZDV at 600 mg/day (200 mg tid or 300 mg bid), plus a marketed protease inhibitor (ritonavir, saquinavir, indinavir, or nelfinavir) at its recommended dose for at least 10 weeks. Allowed: * Inhaled corticosteroids for the treatment of asthma. Exclusion Criteria Co-existing Condition: Patients with the following conditions or symptoms are excluded: * Malabsorption syndromes affecting drug absorption (e.g., Crohn's disease and chronic pancreatitis). * Enrollment in other investigational protocols. Concurrent Medication: Excluded: * Cytotoxic chemotherapeutic agents. * Nonnucleoside reverse transcriptase inhibitors. * Other investigational agents. Concurrent Treatment: Excluded: Radiation therapy. Prior Medication: Excluded: * Cytotoxic chemotherapeutic and immunomodulating agents such as systemic corticosteroids, IF-2, alpha-IFN, beta-IFN, or gamma-IFN (except for inhaled corticosteroids for the treatment of asthma) within 4 weeks of study entry. * HIV immunotherapeutic vaccine within 3 months of study entry. Prior Treatment: Excluded: Radiation therapy within 4 weeks of study entry.