Premium
Pharmacokinetics of the cytochrome P‐450 substrates phenytoin, theophylline, and diazepam in healthy Greyhound dogs
Author(s) -
KuKANICH B.,
NAUSS J. L.
Publication year - 2012
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1111/j.1365-2885.2011.01316.x
Subject(s) - diazepam , oxazepam , theophylline , pharmacokinetics , phenytoin , pharmacology , chemistry , aminophylline , temazepam , bronchodilator , anticonvulsant , oral administration , medicine , benzodiazepine , epilepsy , biochemistry , receptor , psychiatry , asthma
KuKanich, B., Nauss, J. L. Pharmacokinetics of the cytochrome P‐450 substrates phenytoin, theophylline, and diazepam in healthy Greyhound dogs. J. vet. Pharmacol. Therap. 35 , 275–281. The purpose of this study was to determine the pharmacokinetics of phenytoin, theophylline, and diazepam in six healthy Greyhound dogs. Additionally, the pharmacokinetics of the diazepam metabolites, oxazepam and nordiazepam, after diazepam administration was determined. Phenytoin sodium (12 mg/kg), aminophylline (10 mg/kg), and diazepam (0.5 mg/kg) were administered IV on separate occasions, and blood was collected at predetermined time points for the quantification of plasma drug concentrations by florescence polarization immunoassay (phenytoin, theophylline) or mass spectrometry (diazepam, oxazepam, and nordiazepam). The terminal half‐life was 4.9, 9.2, and 1.0 h, respectively, for phenytoin, theophylline, and diazepam, and 6.2 and 2.4 h for oxazepam and nordiazepam after IV diazepam. The clearance was of 2.37, 0.935, and 27.9 mL·min/kg, respectively, for phenytoin, theophylline, and diazepam. The C MAX was 44.7 and 305.2 ng/mL for oxazepam and nordiazepam, respectively, after diazepam administration. Temazepam was not detected above 5 ng/mL in any sample after IV diazepam.