Antinociceptive efficacy of intramuscular administration of morphine sulfate and butorphanol tartrate in tegus (Salvator merianae)

Author(s)

Leal, William P. ; Carregaro, Adriano B. ; Bressan, Thais F. ; Bisetto, Shayne P. ; Melo, Cristiano F. ; Sladky, Kurt K.

• Document type: Journal article
• Source: AMERICAN JOURNAL OF VETERINARY RESEARCH; v. 78, n. 9, p. 1019-1024, SEP 2017.
• Web of Science Citations: 5

Abstract

OBJECTIVE To evaluate the antinociceptive efficacy of IM morphine sulfate or butorphanol tartrate administration in tegus (Salvator merianae). ANIMALS 6 healthy juvenile (12-to 24-month-old) tegus (mean +/- SD body weight, 1,484 +/- 473 g). PROCEDURES In a crossover study design, tegus were randomly assigned to treatment order, with a minimum washout period of 15 days between treatments. Each of 5 treatments was administered IM in a forelimb: saline (0.9% NaCl) solution (0.5 mL), morphine sulfate (5 or 10 mg/kg), or butorphanol tartrate (5 or 10 mg/kg). A withdrawal latency test was used to evaluate antinociception, with a noxious thermal stimulus applied to the plantar surface of the hind limb before (0 hours; baseline) and 0.5, 1, 2, 3, 4, 6, 12, and 24 hours after each treatment. Observers were unaware of treatment received. RESULTS With saline solution, mean hind limb withdrawal latencies (interval to limb withdrawal from the thermal stimulus) remained constant, except at 12 hours. Tegus had higher than baseline mean withdrawal latencies between 0.5 and 1 hour and at 12 hours with morphine at 5 mg/kg and between 1 and 12 hours with morphine at 10 mg/kg. With butorphanol at 5 and 10 mg/kg, tegus maintained withdrawal responses similar to baseline at all assessment points. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that morphine, but not butorphanol, provided antinociception at 5 and 10 mg/kg in tegus as measured by thermal noxious stimulus testing. These data supported the hypothesis that kappa-opioid (but not.-opioid) receptor agonistsprovide antinociception in reptiles. (AU)

• FAPESP's process: 14/10452-9 - Characterization of opioid receptors in the central nervous system and evaluation of analgesic and sedative effects of opioids in tegus (Salvator merianae) and green iguanas (Iguana iguana)
• Grantee: Adriano Bonfim Carregaro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/03247-0 - Evaluation of sedation and analgesia provided by morphine in tegu (Salvator merianae)
• Grantee: William Petroni Leal
• Support Opportunities: Scholarships in Brazil - Master