Rilpivirine Pharmacokinetics Without and With Darunavir/Ritonavir Once Daily in Adolescents and Young Adults

Pediatr Infect Dis J. 2016 Sep;35(9):e271-4. doi: 10.1097/INF.0000000000001214.

Abstract

Background: Rilpivirine (RPV), a recently developed, once daily human immunodeficiency virus non-nucleoside reverse transcriptase inhibitor, is not currently approved for pediatric patients, but is sometimes prescribed for adolescents with multiple treatment failures, for regimen simplification or to minimize toxicity. Darunavir/ritonavir (DRV/r) administered once daily is also increasingly used in adolescents and may alter RPV pharmacokinetics (PK). We evaluated the PK interactions between RPV and DRV/r once daily in adolescents and young adults.

Methods: Human immunodeficiency virus-infected subjects 12 to <24 years old receiving a stable background therapy including RPV 25 mg once daily without or combined with DRV/r 800/100 mg once daily were enrolled. Intensive 24-hour blood sampling was performed, and PK indices were determined using noncompartmental analysis. Protocol-defined target drug exposure ranges based on adult data were used to assess the adequacy of each regimen.

Results: Fifteen subjects receiving RPV without and 14 subjects with DRV/r were enrolled. When dosed without DRV/r, the RPV geometric mean (90% confidence interval) for RPV AUC0-24, Cmax and C24 h were 2.38 μg h/mL (1.92-2.94), 0.14 μg/mL (0.12-0.18) and 0.07 μg/mL (0.03-0.10), respectively, similar to adult values. RPV concentrations were significantly increased with concomitant DRV/r use: RPV AUC24, Cmax and C24 h were 6.74 μg h/mL (4.89-9.28), 0.39 μg/mL (0.27-0.57) and 0.23 μg/mL (0.17-0.32), respectively, well above the target ranges based on adult data. DRV/r PK was not affected by coadministration of RPV.

Conclusions: RPV PK in this adolescent population was similar to adults when dosed without DRV/r. DRV/r coadministration increased RPV exposure 2- to 3-fold, indicating that drug-related side effects should be closely monitored.

Publication types

  • Multicenter Study
  • Observational Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Anti-HIV Agents* / blood
  • Anti-HIV Agents* / pharmacokinetics
  • Anti-HIV Agents* / therapeutic use
  • Child
  • Darunavir / therapeutic use*
  • Drug Interactions
  • Drug Therapy, Combination
  • Female
  • HIV Infections / drug therapy*
  • Humans
  • Male
  • Rilpivirine* / blood
  • Rilpivirine* / pharmacokinetics
  • Rilpivirine* / therapeutic use
  • Ritonavir / therapeutic use*
  • Young Adult

Substances

  • Anti-HIV Agents
  • Rilpivirine
  • Ritonavir
  • Darunavir