title: Effect of semen sampling frequency on seminal antiretroviral drug concentration.
abstract: Study of male genital tract (MGT) pharmacology is relevant to the treatment of prostatitis, prostate cancer, infertility, and seminal human immunodeficiency virus transmission. However, the time course of drug concentrations in the MGT is largely unknown. To determine the feasibility of frequent semen sampling in assessing the pharmacokinetics of the MGT, we administered efavirenz, indinavir, and zidovudine to subjects to achieve steady-state levels and then collected semen samples at sequentially decreasing ejaculation intervals. The volume of seminal plasma decreased from 4.0 (1.2-5.1) ml (median with range) at 48 h after the baseline ejaculation to 0.72 (0.45-1.6) ml 1 h after a previous ejaculation, which was still adequate for drug concentration assessment. The seminal fructose concentration also decreased. However, the concentration of prostate-specific antigen and all three drugs did not decrease, even if the ejaculation intervals decreased to 1 h. Thus, semi-intensive semen sampling can be used to assess MGT pharmacokinetics.
authors.affiliation: Division of Clinical Pharmacology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Cao
authors.forename: T T
authors.initials: TT
authors.lastname: Ndovi
authors.forename: T L
authors.initials: TL
authors.lastname: Parsons
authors.forename: A M
authors.initials: AM
authors.lastname: Guidos
authors.forename: B
authors.initials: B
authors.lastname: Caffo
authors.forename: C W
authors.initials: CW
authors.lastname: Hendrix
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods; D015331:Cohort Studies; D004334:Drug Administration Schedule; D006801:Humans; D008297:Male; D008875:Middle Aged; D012661:Semen / Q000187:drug effects / Q000378:metabolism*; D012669:Seminal Vesicles / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: D044966:Anti-Retroviral Agents