CZAAWE Resource Article

Dosage trials with transmucosal carfentanil citrate in non-human primates
Publication Type 
Journal Article
Year of publication 
Zoo Biology
Abstract 10.1002/(SICI)1098-2361(1999)18:5<397::AID-ZOO4>3.3.CO;2-L The traditional method of immobilizing non-human primates involves remote-delivery injection of anesthetic agents. Orally delivered, transmucosally absorbed opioids have been shown to be a non-stressful alternative method of pre-anesthetic drug administration in children and adults [Stanley et al., 1989]. This report describes several cases using transmucosal carfentanil in non-human primates to determine whether orally delivered carfentanil can be a safe, less stressful, and reversible method of sedation in these species. Regimen 1: Transmucosal carfentanil alone. Three chimpanzees (Pan troglodytes), two capuchin monkeys (Cebus apella), and two gibbons (Hylobates lar) were given carfentanil citrate as their sole pre-medication agent. Doses ranged from 2.0 to 4.0 μg/kg. After a median time of 22 minutes, all chimpanzees were nearly or completely immobilized and showed signs of severe respiratory depression. In contrast, the gibbons and capuchins showed moderate to profound sedation and no signs of respiratory depression. Regimen 2: Oral droperidol followed by transmucosal carfentanil. Four chimpanzees and two bonobos (Pan paniscus) were given a dose of 2.5 mg droperidol orally 45 minutes before transmucosal carfentanil administration. Two chimpanzees received 1.0 μg/kg carfentanil, and all other animals in this trial received a dose of 2.0 μg/kg. All individuals were nearly or completely immobilized with this protocol, and respiratory depression was much less severe. Regimen 3: Oral droperidol followed by transmucosal carfentanil for euthanasia. Two western lowland gorillas (Gorilla gorilla) were electively euthanized using oral droperidol followed by transmucosal carfentanil. Droperidol was administered as in Regimen 2, and doses of carfentanil were 14 μg/kg in the case of a developmentally disabled young gorilla, and 2 μg/kg for a severely debilitated geriatric gorilla with severe respiratory and cardiac disease. Respiratory arrest occurred at 12 and 10 minutes, respectively after carfentanil administration, with subsequent cardiac arrest. Transmucosal carfentanil appears promising as an anesthetic agent when administered alone to gibbons and capuchin monkeys, when administered in combination with droperidol to chimpanzees and bonobos, and when administered for purposes of elective euthanasia in gorillas. Administration of transmucosal carfentanil alone for immobilization of chimpanzees is not recommended because of the severity of respiratory depression observed. Zoo Biol 18:397–402, 1999. © 1999 Wiley-Liss, Inc.