Pyrimethamine pharmacokinetics in human immunodeficiency virus-positive patients seropositive for Toxoplasma gondii.

Journal Article (Clinical Trial;Journal Article)

Pyrimethamine pharmacokinetics were studied in 11 human immunodeficiency virus (HIV)-positive patients who were seropositive for exposure to Toxoplasma gondii and were taking zidovudine (AIDS Clinical Trials Group Protocol 102). Pyrimethamine was administered at 50 mg daily for 3 weeks to achieve steady state, and pharmacokinetic profiles were determined after administration of the last dose. Noncompartmental and compartmental analyses were performed. Population pharmacokinetic analysis assuming a one-compartment model yielded the following estimates: area under the 24-h concentration-time curve, 42.7 +/- 12.3 micrograms.h/ml; halflife, 139 +/- 34 h; clearance, 1.28 +/- 0.41 liters/h; volume of distribution, 246 +/- 641; and absorption rate constant, 1.5 +/- 1.3 liters/h. These values are similar to those seen in subjects without HIV infection. Pyrimethamine pharmacokinetics did not differ significantly in those subjects who were intravenous drug users. Adverse effects were noted in 73% of those initially enrolled in this study, leading to discontinuation for 38%. No association was noted between pyrimethamine levels and the incidence of adverse events. No significant differences were seen in zidovudine pharmacokinetic parameters obtained from studies performed before and during treatment with pyrimethamine. In summary, pyrimethamine exhibited pharmacokinetics in HIV-infected patients that were similar to those in non-HIV-infected subjects and it did not alter the pharmacokinetics of zidovudine in these patients.

Full Text

Duke Authors

Cited Authors

  • Jacobson, JM; Davidian, M; Rainey, PM; Hafner, R; Raasch, RH; Luft, BJ

Published Date

  • June 1996

Published In

Volume / Issue

  • 40 / 6

Start / End Page

  • 1360 - 1365

PubMed ID

  • 8726001

Pubmed Central ID

  • PMC163331

International Standard Serial Number (ISSN)

  • 0066-4804

Digital Object Identifier (DOI)

  • 10.1128/AAC.40.6.1360


  • eng

Conference Location

  • United States