title: Cardiovascular and respiratory effects of tiletamine-zolazepam.
abstract: The combination of tiletamine and zolazepam is an important dissociative anesthetic-tranquilizer. However, little is known about the effects of this combination on the heart and respiration in rats. Adult, male rats anesthetized with tiletamine-zolazepam alone or tiletamine-zolazepam combined with xylazine or butorphanol were evaluated for changes in heart rate, mean arterial blood pressure, arterial blood pH, and blood gases during a 75-min period of anesthesia. Rats anesthetized with tiletamine-zolazepam had increased mean arterial blood pressure and less respiratory depression than did rats anesthetized with sodium pentobarbital. Tiletamine-zolazepam combined with xylazine at either dose produced bradycardia and a marked hypotension that persisted throughout the 75-min period. This combination produced respiratory depression comparable to tiletamine-zolazepam alone. The addition of butorphanol to tiletamine-zolazepam caused a transient hypotension and bradycardia. Tiletamine-zolazepam plus butorphanol produced a mild to severe respiratory depression that was dose and time dependent. These results demonstrate that: a) Tiletamine-zolazepam is cardiostimulatory, a property consistent with the known cardiovascular effects of other dissociative anesthetics; b) xylazine plus tiletamine-zolazepam is a potent cardiovascular depressant combination; and c) tiletamine-zolazepam plus butorphanol at specific doses is an anesthetic-analgesic combination with minimal effects on cardiovascular and respiratory function.
authors.affiliation: Department of Comparative Medicine, College of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
authors.forename: R P
authors.initials: RP
authors.lastname: Wilson
authors.forename: I S
authors.initials: IS
authors.lastname: Zagon
authors.forename: D R
authors.initials: DR
authors.lastname: Larach
authors.forename: C M
authors.initials: CM
authors.lastname: Lang
mesh_terms: D000778:Anesthetics, Dissociative / Q000494:pharmacology*; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002077:Butorphanol / Q000494:pharmacology; D004338:Drug Combinations; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects*; D013992:Tiletamine / Q000494:pharmacology*; D014991:Xylazine / Q000494:pharmacology; D015041:Zolazepam / Q000494:pharmacology*
chemical_list: D000778:Anesthetics, Dissociative; D004338:Drug Combinations; C006131:tiletamine, zolazepam drug combination; D014991:Xylazine; D013992:Tiletamine; D015041:Zolazepam; D002077:Butorphanol