Concentrations of Maraviroc in the Semen of HIV-Infected Men

Inclusion Criteria: * HIV infected male * 18 years old or older * on maraviroc twice daily as part of their antiretroviral regimen for at least 3 months prior to screening * viral load \< 50 copies/mL at least one month prior to enrolling * able to read, understand and sign a written informed consent prior to initiation of the study * medically stable at the time of the study, with no evidence of acute illness Exclusion Criteria: * having difficulty adhering to current antiretroviral therapy * patient is expected to have difficulties adhering with study protocol * patients with malignancy, or acute renal or liver disease * patient with active AIDS-defining illness * patient with any medical, psychiatric or other circumstance that may impede the provision of informed consent * patient with any of the following abnormalities at the time of screening: * hemoglobin \< 85 g/L * absolute neutrophil count \< 1000 cells/uL * platelet count \< 50,000 cells/uL * AST, ALT or total bilirubin \> 3 times the upper limit of normal * serum creatinine \> 1.5 times upper limit of normal * patient receiving concomitant therapy with rifampin or St. John's wort