Affordable Access

Dexamethasone pharmacokinetics in clinically normal dogs during low- and high-dose dexamethasone suppression testing.

Authors
  • Greco, D S
  • Brown, S A
  • Gauze, J J
  • Weise, D W
  • Buck, J M
Type
Published Article
Journal
American Journal of Veterinary Research
Publisher
American Veterinary Medical Association
Publication Date
Apr 01, 1993
Volume
54
Issue
4
Pages
580–585
Identifiers
PMID: 8387253
Source
Medline
License
Unknown

Abstract

Dexamethasone pharmacokinetics was studied in 10 healthy dogs receiving high-dose administration of dexamethasone (dosage, 0.1 mg/kg of body weight, IV), alone or combined with ACTH (dosage, 0.5 U/kg, IV), or low-dose administration of dexamethasone (dosage, 0.01 mg/kg, IV) in an incomplete cross-over design. Serum samples were obtained at 0, 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 360, 480, 720, 1,080, 1,440, 1,920, 2,400, and 2,880 minutes after dexamethasone administration; dexamethasone was measured by radioimmunoassay validated for use in dogs. Dexamethasone pharmacokinetics was adequately described by a two-compartment first-order open model. Comparison of pharmacokinetics for the low- and high-dose protocols revealed dose dependence; area under the curve, mean residence time, clearance, and volume of distribution increased significantly when dexamethasone dosage increased. The elimination rate constant was significantly (P < 0.05) less, and the elimination half-life significantly greater for the high-dose protocols; however, the distribution rate constant and distribution half-life were not significantly different when high-dose protocols were compared with the low-dose protocol. Dose-dependent increases in volume of distribution and clearance may be related to saturation of protein-binding sites. Concurrent administration of ACTH did not affect dexamethasone disposition.

Report this publication

Statistics

Seen <100 times