ABSTRACT
A high-performance liquid chromatographic procedure for the determination of cocaine and selected metabolites (benzoylecgonine, norcocaine and benzoylnorecgonine) from human and canine serum has been developed. The analytes are extracted from 0.5-ml serum samples using strong cation-exchange and octadecylsilane solid-phase extraction columns. Chromatographic separation was accomplished on coupled cyanopropyl and silica columns using acetonitrile-6.25 mM phosphate buffer, pH 2.9 (80:20 v/v) as eluent and a flow-rate of 1.1 ml/min. Low-wavelength UV detection (228 nm, cadmium lamp) allowed detection of 1 ng/ml for each analyte. The assay was linear from 0 to 200 ng/ml (r2 = 0.997-0.999, n = 15 for each analyte) and showed good precision (relative standard deviation = 0.66-13.8%, n = 6) and accuracy (98-115% relative recovery).
Subject(s)
Cocaine/blood , Animals , Chromatography, High Pressure Liquid/methods , Cocaine/analogs & derivatives , Cocaine/pharmacokinetics , Dogs , Humans , Spectrophotometry, UltravioletSubject(s)
Colostomy , Theophylline/pharmacokinetics , Adult , Aged , Female , Humans , Intestinal Absorption , Male , Middle AgedABSTRACT
We determined the intraoperative concentrations of cefmetazole and cefoxitin in serum and muscle from the wound of 30 patients who were undergoing cholecystectomies. The study employed an open-label design in which all patients randomly received cefoxitin sodium (30 mg/kg) or cefmetazole sodium (15 or 30 mg/kg) intravenously with the induction of anesthesia. Total serum and wound-muscle concentrations achieved with cefmetazole 30 mg/kg were significantly greater than those achieved with a similar dose of cefoxitin. Cefmetazole in a 15 mg/kg dose was comparable with cefoxitin 30 mg/kg in achieved concentrations. The elimination half-life for cefoxitin was much shorter than that for cefmetazole (41 min v. 64-68 min, respectively) and this relates to a shorter duration of action for the former. The choice of agent for surgical prophylaxis should incorporate factors relating to drug pharmacokinetic properties as well as microbiological factors.
