Analgesic effects of butorphanol in horses: dose-response studies

Am J Vet Res. 1984 Feb;45(2):211-6.

Abstract

The analgesic effects of butorphanol (0.05, 0.1, 0.2, and 0.4 mg/kg), pentazocine (2.2 mg/kg), and butorphanol vehicle (0.04 ml/kg) were observed in 6 horses. These horses were instrumented to measure response objectively to painful superficial and visceral stimuli. The tested drugs were given IV according to a Latin square design. After preinjection base-line measurements were made, the analgesic effects were observed at 15 and 30 minutes and then at 30-minute intervals until postinjection minute 240. Analgesic effects of butorphanol were dose-related, with durations between 15 and 90 minutes. Duration of analgesia after pentazocine (2.2 mg/kg) was given was between 15 and 30 minutes. When compared with pentazocine, the 0.4 mg/kg dose of butorphanol provided a more intense and longer period of analgesia. A butorphanol dose of 0.2 mg/kg IV appears optimal. On a dose-body weight basis, the potency of butorphanol was 10 to 17 times that of pentazocine. Behavioral side effects were noted with both agents and were dose-related.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesia / veterinary*
  • Animals
  • Behavior, Animal / drug effects
  • Butorphanol / administration & dosage
  • Butorphanol / pharmacology*
  • Dose-Response Relationship, Drug
  • Female
  • Horses*
  • Male
  • Morphinans / pharmacology*
  • Motor Activity / drug effects
  • Pentazocine / administration & dosage
  • Pentazocine / pharmacology
  • Pharmaceutical Vehicles
  • Shivering / drug effects

Substances

  • Morphinans
  • Pharmaceutical Vehicles
  • Butorphanol
  • Pentazocine