Evaluation of thermal antinociceptive effects and pharmacokinetics after intramuscular administration of butorphanol tartrate to American kestrels (Falco sparverius)

Abstract

Butorphanol did not cause thermal antinociception suggestive of analgesia in American kestrels. Sex-dependent responses were identified. Further studies are needed to evaluate the analgesic effects of butorphanol in raptors.

Antinociceptive and respiratory effects following application of transdermal fentanyl patches and assessment of brain μ-opioid receptor mRNA expression in ball pythons

“…Application of a noxious thermal stimulus to an animal’s limb is an established method for assessment of nociception and analgesic efficacy in mammals, 23 birds, 33,34 and reptiles. 11,12,14,20,21 For our experiments in ball pythons, experimental conditions were carefully designed to minimize spontaneous movement and optimize stimulus sensitivity, conditioning, and body location for stimulus application.…”

Analgesic activity of new derivatives of quinazolinone -4

“…Installed sex differences in antinociceptive activity of the compounds II, IV (most pronounced analgesic effect in males compared with females), explains the possibility of the influence of sex hormones [1,7,8,18], consistent with observations of a more powerful and efficient action of butorphanol in males than in females rodents and primates [13], which was interpreted as genetic differences in the formation of sex chromosomes [18]. Award-most manifestation of the analgesic action of the compounds in the female rats in the stage of the estrous cycle proestrus/estrus than in diestrus ½, can probably be explained by the greater sensitivity of the female body in a physiological stress period [15].…”

Advances in Avian Clinical Therapeutics

“…Based on these results, in Hispaniolan Amazon parrots, butorphanol tartrate dosed at 5 mg/kg IV or IM would have to be administered every 2 and 3 hours, respectively, to achieve plasma concentrations consistent with published therapeutic levels. In American kestrels, 46 butorphanol tartrate at 1, 3, and 6 mg/ kg neither significantly increased foot withdrawal thermal thresholds compared with saline administration or baseline values nor produced sedative effects in American kestrels, but instead caused hyperesthesia or hyperalgesia and agitation in males receiving 6 mg/kg of the drug. Butorphanol tartrate administered IM at 6 mg/kg rapidly attained high plasma concentrations (C max 444.68 ng/mL at 0.38 hours) in American kestrels.…”