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Virginia Tech

Pharmacokinetics and pulmonary distribution of Draxxin® (tulathromycin) in healthy adult horses

Abstract

dc:description.abstract

The objective of this study was to determine the pharmacokinetics and tolerance of tulathromycin (Draxxin®; 2.5 mg/kg once) after intramuscular (IM), subcutaneous (SC), and slow intravenous (IV) administration to six adult horses. A three-phase design and 4-week washout period were used. Drug concentrations in blood and bronchoalveolar lavage (BAL) samples were determined by ultra-performance liquid chromatography tandem mass spectrometry and pharmacokinetic parameters calculated using noncompartmental analysis. Following SC and IM administration, all horses exhibited sweating, discomfort, and periods of recumbency. As signs were more severe after SC administration this route was only used in 3/6 horses. Intravenous administration of tulathromycin was well tolerated in all horses. Mean bioavailability was 99.4% IM and 115% SC. Mean maximum plasma concentration was 645 ng/ml IM and 373 ng/ ml SC. Mean half-life was 59.8 h, 54.8 h, and 57.9 h for IV, IM, and SC administration, respectively. Mean clearance was 3.25 ml/kg/min, and mean volume of distribution was 16.8 L/kg following IV administration. Drug was detectable in plasma and BAL samples for 120 h following all routes; however, adverse effects may prevent IM use and SC use is not recommended. Tulathromycin may be a practical and affordable antibacterial for use in adult equine patients.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Biomedical and Veterinary Sciences
Department dc:contributor.department
Biomedical and Veterinary Sciences
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
2021

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Leventhal, Hannah Rani
Chairs dc:contributor.committeechair
  • Davis, Jennifer Lynn
  • Wilson, Katherine E.
Committee members dc:contributor.committeemember
  • Estell, Krista Elise
  • Byron, Christopher R.
  • McKenzie, Harold C.

Subjects

dc:subject × 4

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
vt_gsexam:31213
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/105382

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Leventhal, Hannah Rani. Pharmacokinetics and pulmonary distribution of Draxxin® (tulathromycin) in healthy adult horses. masters thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/105382