This protocol is a stratified, randomized, open-label study of the safety and efficacy of adefovir dipivoxil with indinavir as quadruple therapy in combination with zidovudine and lamivudine, or as triple combination administered with either zidovudine or lamivudine or stavudine for 48 weeks in the treatment of HIV-infected patients with CD4 cell counts >= 100/mm3 and an HIV-1 RNA baseline copy number >= 5000 copies/ml. Patients will be randomized to adefovir dipivoxil, indinavir, zidovudine, and lamivudine or adefovir dipivoxil, indinavir, and a nucleoside inhibitor (randomly assigned to receive zidovudine, lamivudine, or stavudine) or to indinavir, zidovudine, and lamivudine. Additionally, a daily dose of L-carnitine will be administered to all patients randomized to an arm containing adefovir dipivoxil.