Impact of pregnancy on abacavir pharmacokinetics

AIDS. 2006 Feb 28;20(4):553-60. doi: 10.1097/01.aids.0000210609.52836.d1.


Objective: To describe abacavir pharmacokinetics during pregnancy and postpartum; physiological changes during pregnancy are known to affect antiretroviral drug disposition.

Design: The Pediatric AIDS Clinical Trials Group P1026s study is an on-going, prospective, non-blinded pharmacokinetic study of pregnant women receiving one or more antiretroviral drugs for routine clinical care, including a cohort receiving abacavir 300 mg twice daily.

Methods: Serial plasma samples (predose, 1, 2, 4, and 6 h postdose) obtained antepartum (30-36 weeks of gestation) and again postpartum (6-12 weeks after delivery) were assayed for abacavir concentration by reversed-phase high-performance liquid chromatography.

Results: Antepartum evaluations were available for 25 women [mean age, 28.6 years (SD, 6); mean third-trimester weight 92 kg (SD, 35.4); and race/ethnicity 52% black, 28% Hispanic, 16% white, 4% Asian], with geometric mean abacavir area under the concentration-time curve (AUC) of 5.9 mg.h/l [90% confidence interval (CI), 5.2-6.8] and maximum plasma concentration (Cmax) of 1.9 mg/l (90% CI, 1.6-2.2). Seventeen women completed postpartum sampling, and the ratios of antepartum to postpartum AUC and Cmax were 1.04 (90% CI, 0.91-1.18) and 0.79 (90% CI, 0.65-0.98), respectively.

Conclusions: Abacavir AUC during pregnancy was similar to that at 6-12 weeks postpartum and to that for non-pregnant historical controls (5.8 mg.h/l). Consequently, pregnancy does not appear to affect overall abacavir exposure significantly or to necessitate dose adjustments.

Publication types

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

MeSH terms

  • Adult
  • Anti-HIV Agents / pharmacokinetics*
  • Area Under Curve
  • Chromatography, High Pressure Liquid
  • Dideoxynucleosides / pharmacokinetics*
  • Female
  • HIV Infections / drug therapy*
  • HIV-1*
  • Humans
  • Pregnancy
  • Pregnancy Complications, Infectious / drug therapy*
  • Prospective Studies


  • Anti-HIV Agents
  • Dideoxynucleosides
  • abacavir