Impact of pregnancy on abacavir pharmacokinetics.

Abstract

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.

• Authors: Brookie M Best, Mark Mirochnick, Edmund V Capparelli, Alice Stek, Sandra K Burchett, Diane T Holland, Jennifer S Read, Elizabeth Smith, Chengcheng Hu, Stephen A Spector, James D Connor, PACTG P1026s Study Team
• Journal: AIDS (London, England) (AIDS) Vol. 20 Issue 4 Pg. 553-60 (Feb 28 2006) ISSN: 0269-9370 [Print] England
• PMID: 16470119 (Publication Type: Comparative Study, Journal Article, Multicenter Study, Research Support, N.I.H., Extramural)

Chemical References

• Anti-HIV Agents
• Dideoxynucleosides
• abacavir

Topics

• 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