Dosing protocols to increase the efficacy of butorphanol in dogs.
J Vet Pharmacol Ther
; 45(6): 516-529, 2022 Nov.
Article
em En
| MEDLINE
| ID: mdl-36164256
ABSTRACT
The purpose of this study was to improve butorphanol dosing in dogs. Twelve Beagles (6 males, 6 females) were enrolled. Six were randomly allocated to each butorphanol treatment IV (0.4 mg/kg), IV loading dose (0.2 mg/kg) with IV CRI (0.2 mg/kg/h for 8 h), SC (0.4 mg/kg), SC (0.8 mg/kg) with an equal volume sodium bicarbonate (SC-bicarbonate), and IV after CYP inhibitors. We hypothesized that the CRI would produce longer durations than IV bolus, and SC-bicarbonate suspension would produce longer durations than SC. Hypothermia, an opioid effect paralleling antinociception in dogs, and sedation were evaluated. Pharmacokinetics and CYP inhibitor effects on butorphanol pharmacokinetics were determined. Rectal temperatures were significantly lower than baseline from 1.5-4 h (IV), 1-5 h (CRI), and 2-7 h (SC-bicarbonate), but not after SC. Dogs in all treatments had sedation. Butorphanol's half-life was ~1.5 h. SC-bicarbonate had lower bioavailability (61%) relative to SC, with no sustained release, and the CRI mean steady-state plasma concentration was 43.1 ng/ml. CYP inhibitors had minor pharmacokinetic effects on butorphanol. Butorphanol 0.4 mg/kg IV and 0.2 mg/kg loading dose with 0.2 mg/kg/h CRI decreased rectal temperature, but 0.4 mg/kg SC did not. Further studies are required to determine clinical analgesia of butorphanol.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Butorfanol
/
Analgesia
Limite:
Animals
Idioma:
En
Revista:
J Vet Pharmacol Ther
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos