A dose-ranging study of the pharmacokinetics of codeine phosphate following intravenous administration to rats.
The linearity of the pharmacokinetics of codeine was examined in male Sprague-Dawley rats given iv bolus doses of 1, 1.5, 3, and 4 mg/kg of codeine phosphate. Codeine and morphine were determined in serial blood samples utilizing HPLC with electrochemical detection. Codeine exhibits characteristics consistent with a two-compartment pharmacokinetic model. The kinetics of codeine are linear in the iv dose range 1-4 mg/kg. The ratio AUCmorphine:AUCcodeine increases disproportionately with increasing doses of codeine.
Shah
J
J
University of Missouri-Kansas City, School of Pharmacy, MO 64108.
Mason
W D
WD
D000818:Animals; D003061:Codeine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003640:Dealkylation; D004563:Electrochemistry; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine / Q000493:pharmacokinetics; D051381:Rats; D011919:Rats, Inbred Strains
D009020:Morphine; D003061:Codeine