Effect of age on plasma protein binding of several veterinary drugs in dairy calves 2. (December 2018)

• Record Type: Journal Article
• Authors: Mzyk, Danielle A.; Bublitz, Claire M.; Hobgood, Ginger D.; Martinez, Marilyn N.; Davis, Jennifer L.; Smith, Geof W.; Baynes, Ronald E.
• Is Part Of: Research in veterinary science. Volume 121(2018)
• Page Start: 59
• Page End: 64
• Publication Date: 2018-12
• Subjects: Protein binding -- Calves -- Alpha-1-acid glycoprotein -- Albumin; Veterinary medicine -- Periodicals; Veterinary Medicine -- Periodicals; Médecine vétérinaire -- Périodiques; Médecine vétérinaire -- Recherche -- Périodiques; Diergeneeskunde; 636.089
• DOI: 10.1016/j.rvsc.2018.09.004
• Languages: English
• ISSNs: 0034-5288

Abstract

Abstract: The intent of this study was to determine what influence, if any, increasing age has on the binding of drugs to plasma proteins in cattle. Plasma from three different cohorts of calves were used. The first group (n = 20) had plasma samples taken at 1, 7 and 21 days of age. These were compared to results from a second group of calves at 8 weeks and third group sampled at 6 months of age. The plasma protein binding of danofloxacin, florfenicol, flunixin meglumine and tulathromycin was determined in vitro via microcentrifugation using three different drug concentrations spiked into the individual plasma samples derived from each calf. Albumin concentrations were lowest at 1 day of age as compared to plasma samples taken from 2 month old and 6 month old calves. There were significant decreases in alpha1-acid glycoprotein in calves until 21 days of age. However, statistically significant age-effects on plasma protein binding were not observed for any of the drugs evaluated in this study. Findings from these calves suggest that age is not an important factor in the binding of these drugs to plasma proteins. Highlights: Age did not effect plasma protein binding for danofloxacin, flunixin meglumine, tulathromycin or florfenicol in dairy calves. Albumin concentrations were lowest at 1 day and increased until it reached a plateau at 56 days. Plasma concentrations of alpha1 -acid glycoprotein in calves decreased until 21 days of age.