Pharmacokinetics of intravenous and transdermal fentanyl in alpacas.
J Vet Pharmacol Ther
; 40(6): 663-669, 2017 Dec.
Article
em En
| MEDLINE
| ID: mdl-28317124
ABSTRACT
The purpose of the study was to determine pharmacokinetics of fentanyl after intravenous (i.v.) and transdermal (t.d.) administration to six adult alpacas. Fentanyl was administered i.v. (2 µg/kg) or t.d. (nominal dose 2 µg kg-1 hr-1 ). Plasma concentrations were determined using liquid chromatography-mass spectrometry. Heart rate and respiratory rate were assessed. Extrapolated, zero-time plasma fentanyl concentrations were 6.0 ng/ml (1.7-14.6 ng/ml) after i.v. administration, total plasma clearance was 1.10 L hr-1 kg-1 (0.75-1.40 L hr-1 kg-1 ), volumes of distribution were 0.30 L/kg (0.10-0.99 L/kg), 1.10 L/kg (0.70-2.96 L/kg) and 1.5 L/kg (0.8-3.5 L/kg) for V1 , V2 , and Vss , respectively. Elimination half-life was 1.2 hr (0.5-4.3 hr). Mean residence time (range) after i.v. dosing was 1.30 hr (0.65-4.00 hr). After t.d. fentanyl administration, maximum plasma fentanyl concentration was 1.20 ng/ml (0.72-3.00 ng/ml), which occurred at 25 hr (8-48 hr) after patch placement. The area under the plasma fentanyl concentration-vs-time curve (extrapolated to infinity) after t.d. fentanyl was 61 ng*hr/ml (49-93 ng*hr/ml). The dose-normalized bioavailability of fentanyl from t.d. fentanyl in alpacas was 35.5% (27-64%). Fentanyl absorption from the t.d. fentanyl patch into the central compartment occurred at a rate of approximately 50 µg/hr (29-81 µg/hr) between 8 and 72 hr after patch placement.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Camelídeos Americanos
/
Fentanila
/
Analgésicos Opioides
Limite:
Animals
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article