Chemical immobilization in American black bears using a combination of nalbuphine, medetomidine, and azaperone

Safe and effective but unscheduled drug combinations are needed for wildlife immobilization in some jurisdictions. To this end, we evaluated a combination of nalbuphine HCl (40 mg/mL), medetomidine HCl (10 mg/mL), and azaperone tartrate (10 mg/mL)-referred to as NalMed-A (or NAM)-in 28 American black bears (Ursus americanus), captured during June to August 2014 as part of an ongoing study conducted in and around Durango, Colorado, USA. We effectively immobilized all bears; induction (mean +/- SE) was 16.2 +/- 0.9 minutes (n = 25) and reversal was 19 +/- 1.6 minutes (n = 24). Advantages of NalMed-A included low delivery volume, good sedation quality, and effective reversal. Moreover, NalMed-A does not contain compounds regulated by the U.S. Drug Enforcement Administration, making it a useful unscheduled immobilization combination. Based on these and subsequent field experiences, our dosing recommendations are 0.5-1 mL NalMed-A/45.5 kg estimated body mass (0.44-0.88 mg nalbuphine HCl/kg, 0.11-0.22 mg azaperone tartrate/kg, and 0.11-0.22 mg medetomidine HCl/kg), and 5 mg atipamezole HCl/mg medetomidine for antagonism.