Effects of chloramphenicol on infusion pharmacokinetics of propofol in Greyhounds

• Published in: American journal of veterinary research Vol. 56; no. 1; p. 95
• Main Authors: Mandsager, R.E. (Oklahoma State University, Stillwater, OK.), Clarke, C.R, Shawley, R.V, Hague, C.M
• Format: Journal Article
• Language: English
• Published: United States 01.01.1995
• Subjects: ANESTESIA; ANESTESICOS; Anesthesia, Intravenous - veterinary; ANESTHESIE; ANESTHESIQUE; Animals; ASSOCIATION MEDICAMENTEUSE; Body Temperature - drug effects; CHIEN; CHIEN DE CHASSE; CHLORAMPHENICOL; Chloramphenicol - pharmacology; CLORAMFENICOL; Dogs - metabolism; Drug Interactions; FARMACOLOGIA; Female; Hemodynamics - drug effects; Male; MEDICAMENT; MEDICAMENTOS; METABOLISME; METABOLISMO; MEZCLA DE MEDICAMENTOS; PERRO; PERRO DE CACERIA; PHARMACOLOGIE; Propofol - blood; Propofol - pharmacokinetics; RACE (ANIMAL); RAZAS (ANIMALES); Respiration - drug effects; Time Factors
• ISSN: 0002-9645; 1943-5681
• DOI: 10.2460/ajvr.1995.56.01.95

To investigate the effect of chloramphenicol, a cytochrome P-450 inhibitor, on the pharmacokinetics of propofol, either chloramphenicol (50 mg/kg of body weight, IV) or saline solution was administered IV to 5 Greyhounds in randomized manner, with at least 2 weeks between trials. Thirty minutes after either chloramphenicol or saline treatment, a bolus dose of propofol (10 mg/kg IV) was administered, followed by a 2-hour infusion of propofol (0.4 mg/kg/min, IV). Samples for determination of blood propofol concentration were collected sequentially over a 6-hour period during each trial. After termination of propofol infusion, the time to spontaneous head lift, extubation, sternal recumbency, and standing was recorded. Blood propofol concentration was determined by use of high-performance liquid chromatography. Concentration-time data were fitted to a two-compartment open pharmacokinetic model and pharmacokinetic variables were determined, using a microcomputer program for modeling and simulation of concentration-time data. The effect of chloramphenicol on the pharmacokinetics of propofol and recovery time were evaluated, using paired t-tests and Wilcoxon's test for parameters that are not normally distributed (t1/2(beta), Vd(ss), Cl(B)). Significant (P 0.05) effects of chloramphenicol pretreatment included increased t1/2(5) (by 209%), and decreased Cl(B) (by 45%), and prolonged recovery indices (by 768 to 946%). These results indicate that cytochrome P-450 metabolic pathways have an important role in propofol clearance and propofol anesthetic recovery in Greyhounds