title: Pharmacokinetics and pharmacodynamics of propofol with or without 2% benzyl alcohol following a single induction dose administered intravenously in cats.
abstract: OBJECTIVE
  To compare the pharmacokinetics and pharmacodynamics of propofol with or without 2% benzyl alcohol administered intravenously (IV) as a single induction dose in cats.
  
  
  METHODS
  Prospective experimental study.
  
  
  METHODS
  Six healthy adult cats, three female intact, three male castrated, weighing 4.8 ± 1.8 kg.
  
  
  METHODS
  Cats received 8 mg kg(-1) IV of propofol (P) or propofol with 2% benzyl alcohol (P28) using a randomized crossover design. Venous blood samples were collected at predetermined time points to 24 hours after drug administration to determine drug plasma concentrations. Physiologic and behavioral variables were also recorded. Propofol and benzyl alcohol concentrations were determined using high pressure liquid chromatography with fluorescence detection. Pharmacokinetic parameters were described using a 2-compartment model. Pharmacokinetic and pharmacodynamic parameters were analyzed using repeated measures anova (p < 0.05).
  
  
  RESULTS
  Plasma concentrations of benzyl alcohol were below the lower limits of quantification (LLOQ) at all time points for two of the six cats (33%), and by 30 minutes for the remaining four cats. Propofol pharmacokinetics, with or without 2% benzyl alcohol, were characterized by rapid distribution, a long elimination phase, and a large volume of distribution. No differences were noted between treatments with the exception of clearance from the second compartment (CLD2), which was 23.6 and 38.8 mL kg(-1)  minute(-1) in the P and P28 treatments, respectively. Physiologic and behavioral variables were not different between treatments with the exception of heart rate at 4 hours post administration.
  
  
  CONCLUSIONS
  The addition of 2% benzyl alcohol as a preservative minimally altered the pharmacokinetics and pharmacodynamics of propofol 1% emulsion when administered as a single IV bolus in this group of cats. These data support the cautious use of propofol with 2% benzyl alcohol for induction of anesthesia in healthy cats.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Gregg M
authors.initials: GM
authors.lastname: Griffenhagen
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Marlis L
authors.initials: ML
authors.lastname: Rezende
authors.affiliation: Pharmacology Core Laboratory, Department of Clinical Sciences, Animal Cancer Center, Colorado State University, Fort Collins, CO, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Gustafson
authors.affiliation: Pharmacology Core Laboratory, Department of Clinical Sciences, Animal Cancer Center, Colorado State University, Fort Collins, CO, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Hansen
authors.affiliation: Pharmacology Core Laboratory, Department of Clinical Sciences, Animal Cancer Center, Colorado State University, Fort Collins, CO, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Lunghofer
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Khursheed R
authors.initials: KR
authors.lastname: Mama
mesh_terms: D000762:Anesthesia Recovery Period; D000771:Anesthesia, Intravenous / Q000662:veterinary; D018686:Anesthetics, Intravenous / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D000818:Animals; D019905:Benzyl Alcohol / Q000008:administration & dosage*; D002415:Cats / Q000378:metabolism / Q000502:physiology*; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D005260:Female; D008297:Male; D015742:Propofol / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D011446:Prospective Studies
chemical_list: D018686:Anesthetics, Intravenous; D019905:Benzyl Alcohol; D015742:Propofol
keywords: anesthesia; cat; propofol