Lopinavir/Ritonavir in Combination With Saquinavir Mesylate or Lamivudine/Zidovudine to Explore Metabolic Toxicities in Antiretroviral HIV-Infected Subjects

Inclusion Criteria: * Subject is naïve to antiretroviral treatment (subjects may not have more than 7 days of any antiretroviral treatment). * Subject is at least 18 years of age, inclusive. * If female, subject is either not of childbearing potential, defined as postmenopausal for at least 1 year or surgically sterile (bilateral tubal ligation, bilateral oophorectomy or hysterectomy), or is of childbearing potential and practicing one of the following methods of birth control:condoms, sponge, foams, jellies, diaphragm or intrauterine device(IUD), a vasectomized partner, total abstinence from sexual intercourse * If female, the results of a urine pregnancy test performed at screening (urine specimen obtained no earlier than 28 days prior to study drug administration) is negative. * Subject is not breast-feeding. * Vital signs, physical examination and laboratory results do not exhibit evidence of acute illness. * Subject has no significant history of cardiac, renal, neurologic, psychiatric, oncologic, endocrinologic, metabolic or hepatic disease that would in the opinion of the investigator adversely affect his/her participating in this study. * Subject does not require and agrees not to take any of the following medications for the duration of the study: midazolam, triazolam, terfenadine, astemizole, cisapride, pimozide, propafenone, flecainide, certain ergot derivatives (ergotamine, dihydroergotamine, ergonovine, and methylergonovine), rifampin, lovastatin, simvastatin, an…