Study of Lopinavir/Ritonavir Tablets Comparing Once-Daily Versus Twice-Daily Administration When Coadministered With Nucleoside/Nucleotide Reverse Transcriptase Inhibitors in Antiretroviral-Experienced Human Immunodeficiency Virus Type 1 Infected Subjects

Inclusion Criteria: * Subjects were human immunodeficiency virus type 1 (HIV-1) positive, antiretroviral-experienced adults at least 18 years of age currently receiving an antiretroviral regimen which had not changed for at least 12 weeks. * Subjects had plasma HIV-1 ribonucleic acid (RNA) levels \> 1,000 copies/mL at screening and were not acutely ill. * Subject was currently failing his/her antiretroviral regimen with the most recent 2 consecutive prestudy plasma HIV-1 RNA levels \> 400 copies/mL with the most recent being \> 1000 copies/mL, and in the investigator's opinion, should change therapy * Female subjects were nonpregnant and nonlactating. Exclusion Criteria: * Subjects were excluded if screening laboratory analyses showed hemoglobin \<= 8.0 grams per deciliter. * Subjects were excluded if screening laboratory analyses showed absolute neutrophil count \<= 750 cells/microliter. * Subjects were excluded if screening laboratory analyses showed platelet count \<= 50,000 per cubic millimeter. * Subjects were excluded if screening laboratory analyses showed alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \>= 5.0 x upper limit of normal (ULN).