Impact of Menstrual Cycle on Antiretroviral Pharmacokinetics in HIV-Infected Women

Data suggests that women taking drugs to treat human immunodeficiency virus (HIV) have higher amounts of drugs in their body compared with men taking the same dose of anti-HIV drugs. The reason for this higher drug exposure has not yet been determined. The primary purpose of this study is to examine whether a pharmacokinetics (factors that determine the amount of drug in the body) of anti-HIV drugs change during different phases of the menstrual cycle in women and ultimately result in higher amounts of drug in the body compared with men. In other words, we plan to examine whether changes in sex hormones throughout the menstrual cycle affect the amount of anti-HIV drugs in HIV infected women. The antiretroviral drugs atazanavir, ritonavir, tenofovir and emtricitabine will be studied.