Format

Send to:

Choose Destination
See comment in PubMed Commons below
Clin Pharmacol Ther. 2011 Jul;90(1):151-6. doi: 10.1038/clpt.2011.99. Epub 2011 Jun 1.

The male genital tract is not a pharmacological sanctuary from efavirenz.

Author information

  • 1Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Abstract

Many antiretroviral (ARV) drugs have large blood plasma-to-seminal plasma (BP/SP) concentration ratios. Concern exists that these drugs do not adequately penetrate the male genital tract (MGT), resulting in the MGT becoming a "pharmacological sanctuary" from these agents, with ineffective MGT concentrations despite effective blood concentrations. Efavirenz (EFV) is the most highly protein-bound ARV drug, with >99% binding in blood plasma and the largest BP/SP total EFV concentration ratio, reportedly ranging from 11 to 33. To evaluate protein binding as an explanation for the differences between the drug concentrations in blood and semen, we developed a novel ultrafiltration method, corrected for the duration of centrifugation, to measure protein binding in the two matrices. In six subjects, protein-free EFV concentrations were the same in blood and semen; the median (interquartile range (IQR)) protein-free EFV SP/BP ratio was 1.21 (0.99-1.35); EFV protein binding was 99.82% (99.79-99.86) in BP and 95.26% (93.24-96.67) in SP. This shows that the MGT is not a sanctuary from EFV.

PMID:
21633344
[PubMed - indexed for MEDLINE]
PMCID:
PMC3215581
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for John Wiley & Sons, Inc. Icon for PubMed Central
    Loading ...
    Write to the Help Desk