Effect of Gender and HIV Infection on Zidovudine and Lamivudine Pharmacokinetics

Inclusion Criteria: * Documented physician-diagnosed HIV-infection (HIV+ antibody or plasma HIV-RNA+); HIV-negative volunteers must have a negative HIV-ELISA. * Age 18 to 55 years; * Either antiretroviral naïve, or no HIV-therapy in the preceding 6 months; * Planned antiretroviral regimen includes standard doses of ZDV plus 3TC as part of the antiretroviral regimen. Once- or twice-daily 3TC will be allowed. Exclusion Criteria: * Any medical condition that in the opinion of the investigators would jeopardize the intent of the study. * In the opinion of the investigator, any concomitant immunomodulatory medications, chemotherapeutic agents, investigational drugs, and alternative therapies, including, glucocorticoids, recombinant growth factors or cytokines (e.g. Granulocyte-macrophage colony-stimulating factor, Granulocyte colony-stimulating factor, interferon-alpha or gamma, human growth hormone, etc), ribavirin, birth-control pills, and sex hormones that could interfere with the cellular pharmacology of the study medications; * Concomitant medications that interfere with renal drug clearances including, tenofovir, adefovir, cidofovir, ganciclovir, probenecid, or any similarly problematic medication in the opinion of the investigators; * Concomitant warfarin or daily aspirin (to prevent excess bleeding from biopsy). * Pregnancy or a plan to become pregnant, or menopause; * Any \> or = grade II abnormality in hemoglobin, absolute neutrophil count, routine liver function test…