Differences in Blood Levels of Lopinavir/Ritonavir in HIV Infected Men and Women

• Lopinavir (LPV) area under the concentration-time curve (AUC) for 0 to 12 hours
  

• LPV maximum concentration (Cmax), concentration at 12 hours (C12h), and apparent oral clearance (CL/F)
  
• LPV AUC for 0 to 12 hours, Cmax, C12h, CL/F, and participant's race and ethnicity
  
• LPV AUC for 0 to 12 hours, Cmax, C12h, CL/F, participant's age, weight, and body mass index (BMI), and coadministration of TDF
  
• LPV AUC for 0 to 12 hours, Cmax, C12h, CL/F, and graded signs and symptoms
  
• LPV AUC for 0 to 12 hours, Cmax, C12h, CL/F, and graded gastrointestinal signs and symptoms (defined as nausea, vomiting, diarrhea, abdominal pain, and bloating)
  
• ritonavir (RTV) AUC for 0 to 12 hours, Cmax, C12h, and CL/F
  
• LPV/r AUC for 0 to 12 hours, Cmax, C12h, CL/F for both the soft gel capsule and tablet formulations
  

It is estimated that 50% of people living with HIV/AIDS worldwide are women. HIV infected women face different psychosocial issues than men, and their bodies may react differently to HIV treatment. However, most of the data on the safety and efficacy of antiretrovirals (ARVs) used in the treatment of HIV infection are from studies conducted primarily in men. LPV/r in tablet form was approved by the FDA in October 2005. This study will determine the differences in pharmacokinetics (PK) in men and women taking a soft gel capsule and a tablet formulation of LPV/r.

No ARVs will be provided by this study. In Step 1, participants will receive soft gel capsules of LPV/r. All Step 1 participants will be asked to join Step 2 of the study upon completion of Step 1. In Step 2, participants will receive tablets of LPV/r. During the study, participants in both Step 1 and 2 will take a treatment regimen of LPV/r twice daily and one or more of the following: a nucleoside reverse transcriptase inhibitor (NRTI), tenofovir disoproxil fumarate, or enfuvirtide. Medical and medication history, blood collection, and clinical assessments will occur at study screening for both Steps 1 and 2. Participants in both steps will be asked to complete a medication diary from study entry to the day of the PK visit. The PK visit will occur within 30 days of study screening; blood collection for PK analysis will also occur at this visit.