Pharmacokinetics of tulathromycin in plasma and milk samples after a single subcutaneous injection in lactating goats (Capra hircus). Issue 2 (25th July 2013)

• Record Type: Journal Article
• Authors: Grismer, B.; Rowe, J. D.; Carlson, J.; Wetzlich, S. E.; Tell, L. A.
• Is Part Of: Journal of veterinary pharmacology and therapeutics. Volume 37:Issue 2(2014)
• Page Start: 205
• Page End: 208
• Publication Date: 2013-07-25
• Subjects: Veterinary pharmacology -- Periodicals; Therapeutics -- Periodicals; 636.0895105
• DOI: 10.1111/jvp.12071
• Languages: English
• ISSNs: 0140-7783

Abstract

<abstract abstract-type="main" id="jvp12071-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Eight adult female dairy goats received one subcutaneous administration of tulathromycin at a dosage of 2.5 mg/kg body weight. Blood and milk samples were assayed for tulathromycin and the common fragment of tulathromycin, respectively, using liquid chromatography/mass spectrometry. Pharmacokinetic disposition of tulathromycin was analyzed by a noncompartmental approach. Mean plasma pharmacokinetic parameters (±SD) following single‐dose administration of tulathromycin were as follows: <italic>C</italic><sub>max</sub> (121.54 ± 19.01 ng/mL); T<sub>max</sub> (12 ± 12–24 h); area under the curve AUC<sub>0→∞</sub> (8324.54 ± 1706.56 ng·h/mL); terminal‐phase rate constant λz (0.01 ± 0.002 h<sup>−1</sup>); and terminal‐phase rate constant half‐life <italic>t</italic><sub>1/2λz</sub> (67.20 h; harmonic). Mean milk pharmacokinetic parameters (±SD) following 45 days of sampling were as follows: <italic>C</italic><sub>max</sub> (1594 ± 379.23 ng/mL); T<sub>max</sub> (12 ± 12–36 h); AUC<sub>0→∞</sub> (72, 250.51 ± 18, 909.57 ng·h/mL); λz (0.005 ± 0.001 h<sup>−1</sup>); and <italic>t</italic><sub>1/2λz</sub> (155.28 h; harmonic). All goats had injection‐site reactions that diminished in size over time. The conclusions from this study were that tulathromycin residues are detectable in milk samples from adult goats for at least 45 days following subcutaneous administration, this therapeutic option should be reserved for cases where other treatment options have failed, and goat milk should be withheld from the human food chain for at least 45 days following tulathromycin administration.</p> </abstract>