• Percentage of patients with HIV-RNA levels < 50 c/ml (intent-to-treat [ITT])
  

• Percentage of patients with HIV-RNA level < 400 c/ml
  
• Time to therapy failure
  
• CD4 cell count increase from Baseline to Week 48 (w48)
  
• Quality of life changes
  
• Compliance to both treatment regimens
  
• Description of adverse events
  

Inclusion Criteria:

• Chronic HIV infection with plasma RNA viral burden of HIV > 2,000 copies/ml obtained in the month prior to randomization.
• Ages 18 years or older.
• Women with childbearing potential should use an effective contraceptive method.
• The subjects should give their written informed consent.

• The subjects should provide the baseline laboratory values measured during the 4 weeks prior to the start of the study drugs, specified below:

  • serum creatinine < 1.5 times the upper normal limit;
  • total amylase < 1.4 times the upper normal limit;
  • liver enzymes (AST, ALT) < 4 times the upper normal limit.

Exclusion Criteria:

• Previous antiretroviral treatment.
• Suspected (acute) primary HIV infection starting less than six months before.
• Suspected or proven acute hepatitis in the 30 days prior to inclusion in the study. Subjects with chronic hepatitis are eligible provided their liver function enzymes < 4 times the upper normal limit.
• Previous therapy with agents with a significant potential of systemic myelosuppression, neurotoxicity, pancreatotoxicity, liver toxicity or cytotoxicity in the 3 months prior to the start of the study, or expected need for requiring therapy on inclusion, or therapy with methadone or ribavirin/interferons or treatment with neurotoxic drugs or drugs affecting CYP 3A4.
• Patients under methadone program
• Abuse of alcohol or drugs, sufficient, in the investigator's opinion, to prevent an adequate compliance with the study treatment or that could increase the risk of developing pancreatitis or toxic hepatitis.
• Untreatable diarrhea (> 6 loose stools/day for at least 7 consecutive days) within the 30 days prior to inclusion in the study.
• Pregnancy or nursing.
• History of bilateral peripheral neuropathy or signs and symptoms of bilateral peripheral neuropathy > Grade 2 on screening.
• Inability to tolerate oral drugs.
• Any other clinical condition or previous therapy that, in the investigator's opinion, leads the patient to be inadequate for the study or unable to comply with the dosage requirements.