Comparative pharmacokinetics of phenylbutazone in healthy young-adult and geriatric horses.
Am J Vet Res
; 85(8)2024 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-38942059
ABSTRACT
OBJECTIVE:
To evaluate the effects of aging on phenylbutazone (PBZ) disposition in older horses (≥ 25 years old) compared to young adults (4 to 10 years old) by characterizing the pharmacokinetic profile of PBZ and its active metabolite, oxyphenbutazone (OPBZ), following a 2.2-mg/kg dose, IV. We hypothesized that the disposition of PBZ will be affected by age. ANIMALS 16 healthy horses (8 young adults aged 4 to 10 years and 8 geriatric horses ≥ 25 years old).METHODS:
Horses were administered a single 2.2-mg/kg PBZ dose, IV. Plasma samples were collected at designated time points and frozen at -80 °C until assayed using liquid chromatography-tandem mass spectrometry. Pharmacokinetic analyses were performed using Phoenix WinNonlin, version 8.0 (Certara). Both clinical and pharmacokinetic data were compared between age groups using independent samples t tests, with P < .05 considered significant.RESULTS:
Baseline characteristics did not differ between groups, with the exception of age, weight, and plasma total solids. Plasma concentrations of PBZ were best described by a two-compartment model. The maximum plasma concentration of OPBZ was reached at 5 hours for both age groups, and the metabolite-to-parent-drug area-under-the-curve ratios were approximately 20% for both groups. None of the pharmacokinetic parameters of PBZ or its metabolite, OPBZ, differed significantly between age groups. CLINICAL RELEVANCE The hypothesis was rejected as there was no significant difference in PBZ disposition in young-adult horses compared to geriatric horses. Our data do not support the need for dose adjustments of PBZ in clinically healthy geriatric horses.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Envejecimiento
/
Fenilbutazona
Límite:
Animals
Idioma:
En
Revista:
Am J Vet Res
Año:
2024
Tipo del documento:
Article
País de afiliación:
Marruecos