Population Pharmacokinetic Modeling of Tenofovir in the Genital Tract of Male HIV-Infected Patients

Antimicrob Agents Chemother. 2017 Feb 23;61(3):e02062-16. doi: 10.1128/AAC.02062-16. Print 2017 Mar.

Abstract

The aims of this study were to describe the blood plasma (BP) and seminal plasma (SP) pharmacokinetics of tenofovir (TFV) in HIV-1-infected men, to assess the role of genetic polymorphism in the variability of TFV transfer into the male genital tract, and to evaluate the impact of TFV SP exposure on seminal plasma HIV load (spVL). Men from the Evarist-ANRS EP 49 study treated with TFV as part of their antiretroviral therapy were included in the study. A total of 248 and 217 TFV BP and SP concentrations from 129 men were available for the analysis. For pharmacogenetic assessment, a total of 121 single nucleotide polymorphisms (SNP) were genotyped. Data were analyzed using a nonlinear mixed-effects modeling approach. TFV pharmacokinetics were best described by a two-compartment model for BP and by an effect compartment with different input and output constants for SP. TFV exposures (area under the concentration-time curve from 0 to 24 h [AUC0-24]) were higher in SP than in BP (median AUC0-24, 7.01 versus 2.97 mg · liter-1 · h, respectively). The median (range) SP-to-BP AUC0-24 ratio was 2.24 (0.53 to 34.13). After correction for multiple testing, none of the SNPs were significantly associated with the TFV transfer rate constant. The impact of the TFV SP AUC0-24 or TFV SP-to-BP AUC0-24 ratio on spVL was not significant (P = 0.808 and 0.768, respectively). This is the first population model describing TFV pharmacokinetics in the male genital tract. TFV SP concentrations were higher than BP concentrations. Despite TFV SP exposures being higher than BP exposures, an spVL was detectable for 12.2% of the men.

Keywords: genital tract; population pharmacokinetics; seminal plasma; tenofovir.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-HIV Agents / blood
  • Anti-HIV Agents / pharmacokinetics*
  • Anti-HIV Agents / pharmacology
  • Area Under Curve
  • Bayes Theorem
  • Biological Availability
  • Body Weight
  • Drug Administration Schedule
  • Drug Dosage Calculations
  • Gene Expression
  • Genitalia, Male / chemistry
  • Genitalia, Male / drug effects*
  • Genitalia, Male / virology
  • HIV Infections / blood
  • HIV Infections / drug therapy*
  • HIV Infections / virology
  • HIV Reverse Transcriptase / antagonists & inhibitors
  • HIV Reverse Transcriptase / genetics
  • HIV Reverse Transcriptase / metabolism
  • HIV-1 / drug effects*
  • HIV-1 / genetics
  • HIV-1 / growth & development
  • Humans
  • Male
  • Markov Chains
  • Microbial Sensitivity Tests
  • Middle Aged
  • Models, Statistical*
  • Monte Carlo Method
  • Polymorphism, Single Nucleotide
  • Semen / chemistry
  • Semen / drug effects
  • Semen / virology
  • Tenofovir / blood
  • Tenofovir / pharmacokinetics*
  • Tenofovir / pharmacology

Substances

  • Anti-HIV Agents
  • Tenofovir
  • reverse transcriptase, Human immunodeficiency virus 1
  • HIV Reverse Transcriptase