title: Etravirine concentrations in seminal plasma in HIV-infected patients.
abstract: OBJECTIVE
  To determine etravirine concentrations and the HIV-1 viral load (VL) in blood plasma (BP) and seminal plasma (SP) of HIV-infected patients.
  
  
  METHODS
  Ten adult antiretroviral-experienced HIV-1 patients receiving an etravirine-containing regimen for at least 1 month were enrolled. Semen and blood samples were collected ~12 or 24 h after the last etravirine dose, depending on twice-daily or once-daily dosing, respectively. Liquid chromatography tandem mass spectrometry was used to determine etravirine concentrations and HIV-1 VL was determined by real-time PCR (detection limit 40 copies/mL). Results are presented as the median (range) unless otherwise indicated.
  
  
  RESULTS
  Ten blood and 20 semen samples were collected. The CD4 count was 502 (252-817) cells/mm(3) and the BP VL was <40 (<40-362) copies/mL. The time on etravirine was 52 (12-124) weeks. The BP etravirine concentration was 452.5 (258-751) ng/mL. The SP etravirine concentration was 62.9 (31.2-166.0) ng/mL and values were above the IC(50) range (0.39-2.4 ng/mL) in all cases. The median etravirine SP:BP ratio was 0.16 (0.07-0.26). The SP VL was <40 copies/mL in all patients, whereas the BP VL was detectable in one patient with poor adherence to treatment.
  
  
  CONCLUSIONS
  Etravirine concentrations in male genital secretions are modest, reaching only 16% of the BP concentration. Nevertheless, they are more than 10 times greater than the wild-type IC(50) range (not adjusted for protein binding).
authors.affiliation: HIV Unit, Infectious Disease Service, Hospital Universitari de Bellvitge,  L'Hospitalet de Llobregat, 08907 Barcelona,  Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Tiraboschi
authors.forename: J
authors.initials: J
authors.lastname: Niubo
authors.forename: E
authors.initials: E
authors.lastname: Ferrer
authors.forename: G
authors.initials: G
authors.lastname: Barrera-Castillo
authors.forename: N
authors.initials: N
authors.lastname: Rozas
authors.forename: M
authors.initials: M
authors.lastname: Maso-Serra
authors.forename: D
authors.initials: D
authors.lastname: Podzamczer
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D015497:HIV-1 / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009570:Nitriles; D011724:Pyridazines / Q000097:blood / Q000378:metabolism* / Q000627:therapeutic use*; D011743:Pyrimidines; D012661:Semen / Q000187:drug effects* / Q000378:metabolism*; D019562:Viral Load / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D009570:Nitriles; D011724:Pyridazines; D011743:Pyrimidines; C451734:etravirine