Population pharmacokinetics of a single intramuscular administration of tulathromycin in adult desert tortoises (Gopherus agassizii). Issue 5 (10th March 2014)

• Record Type: Journal Article
• Authors: Kinney, M. E.; Lamberski, N.; Wack, R.; Foster, R.; Neely, M.; Tell, L.; Gehring, R.
• Is Part Of: Journal of veterinary pharmacology and therapeutics. Volume 37:Issue 5(2014)
• Page Start: 500
• Page End: 507
• Publication Date: 2014-03-10
• Subjects: Veterinary pharmacology -- Periodicals; Therapeutics -- Periodicals; 636.0895105
• DOI: 10.1111/jvp.12118
• Languages: English
• ISSNs: 0140-7783

Abstract

<abstract abstract-type="main" id="jvp12118-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Tulathromycin, a long acting macrolide antibiotic, has demonstrated efficacy against respiratory pathogens including <italic>Mycoplasma bovis</italic> and <italic>M. hyopneumoniae</italic>. A pharmacokinetic study was performed to evaluate the clinical applicability of tulathromycin in desert tortoises following a single intramuscular dose of 5 mg/kg. A single blood sample was collected from 110 different desert tortoises at 0.25, 0.5, 1, 4, 8, 24, 48, 72, 120, and 240 h following drug administration. Plasma concentrations of the parent form of tulathromycin were measured using liquid chromatography/mass spectrometry. As each tortoise was only bled once, pharmacokinetic parameters were initially estimated using a naïve pooled data approach. Given the variability in the data, population‐based compartmental modeling was also performed. Using nonparametric population compartmental modeling, a two‐compartment model with first‐order absorption and elimination best fit the data. An observed <italic>C</italic><sub>max</sub> of 36.2 ± 29.7 <italic>μ</italic>g/mL was detected at 0.25 h (observed <italic>T</italic><sub>max</sub>). The elimination half‐life (<italic>T</italic><sub>½el</sub>) was long (77.1 h) resulting in detectable plasma concentrations 240 h postadministration. This study represents a preliminary step in evaluating the utility of tulathromycin in chelonian species and demonstrates that population data modeling offers advantages for estimating pharmacokinetic parameters where sparse data sampling occurs and there is substantial variability in the data.</p> </abstract>