In this open-label, nonrandomized study, 120 HIV-infected patients are stratified into two groups: failed nelfinavir vs protease inhibitor-naive. All patients receive indinavir plus efavirenz plus adefovir dipivoxil plus and L-carnitine, orally. Plasma vRNA is measured every 4 weeks until Week 16, then every 8 weeks for the remainder of the 48-week study.

Inclusion Criteria

Patients must have:

• Serologically documented HIV infection.
• Baseline CD4 count greater than or equal to 50 cells and vRNA greater than or equal to 10,000 copies/ml.
• Parental consent for patients under 18.

Nelfinavir-Failure Group:

• Must have protease inhibitor experience solely with nelfinavir and be considered drug-adherent.
• Must be candidate for changing therapy because of virologic failure and be receiving nelfinavir at entry (at least 16 weeks of nelfinavir plus NRTI therapy with at least a 10-fold decline in vRNA due to nelfinavir therapy and a subsequent increase toward the patient's baseline vRNA of at least 10-fold).

Control Group:

• Must have received any combination of currently licensed nucleoside reverse transcriptase inhibitors for at least 16 weeks.
• Must be naive to efavirenz, adefovir dipivoxil, and other NRTI's.

Exclusion Criteria

Prior Medication:

Excluded:

Control group:

• Prior efavirenz, adefovir dipivoxil, or other non-nucleoside reverse transcriptase inhibitors.

Required:

Nelfinavir-failure patients:

• At least 16 weeks of nelfinavir.

Control group:

• At least 16 weeks of any combination of currently licensed nucleoside reverse transcriptase inhibitors.