A Dosing Regimen for Oral Carfentanil Immobilization with Intranasal Naltrexone Reversal for Restraint of Lion-Tailed Macaques (Macaca silenus)
American Association of Zoo Veterinarians Conference 2005
Jennifer C. Smith1, DVM, DACLAM; Sheilah A. Robertson2, BVMS, PhD, DACVA; Kris Springsteen3, LVT; Dalen W. Agnew4, DVM, DACVP; Ann E. Duncan5, DVM; Brad Bolon6, DVM, MS, PhD
1Department of Pharmacology and Pathology, Amgen, Inc., Thousand Oaks, CA, USA; 2Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; 3Department of Anesthesia, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; 4Department of Pathology, Microbiology, and Immunology, College of Veterinary Medicine, University of California, Davis, CA, USA; 5Detroit Zoological Institute, Royal Oak, MI, USA; 6GEMpath Inc., Cedar City, UT, USA
An oral carfentanil anesthetic protocol, with reversal by intranasal naltrexone, was evaluated as a new method for immobilizing lion-tailed macaques (Macaca silenus). Five adult macaques were given carfentanil-laced marshmallows. At doses of 60 mg/kg, anesthesia occurred within 12 minutes of consumption and was followed within 4 minutes by profound cardiopulmonary depression. Both apnea and bradycardia were restored within 1 minute by administering intranasal (IN) naltrexone (30 mg/kg). A low carfentanil dose (0.05 mg/kg) did not induce adequate anesthesia. A carfentanil dose of 0.1 mg/kg produced immobilization without toxicity within 30 minutes and was readily reversed using less naltrexone (3 mg/kg IN). This data demonstrates that oral carfentanil (0.1 mg/kg) effectively immobilizes adult lion-tailed macaques, indicates that this species is more sensitive to carfentanil toxicity than are other non-human primates, and shows that intranasal naltrexone rapidly reverses both immobilization and toxicity induced by carfentanil. The protocol was also successfully used in a field situation to capture and recover a spider monkey (Ateles geoffroyi).