Email updates

Keep up to date with the latest news and content from BMC Veterinary Research and BioMed Central.

Open Access Research article

Pharmacokinetic analysis of topical tobramycin in equine tears by automated immunoassay

Sarah L Czerwinski1, Andrew W Lyon23, Brian Skorobohach4 and Renaud Léguillette1*

Author affiliations

1 Department of Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada

2 Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Calgary, Calgary, AB, Canada

3 Calgary Laboratory Services, Calgary, AB, Canada

4 Calgary Animal Referral and Emergency Centre, Calgary, AB, Canada

For all author emails, please log on.

Citation and License

BMC Veterinary Research 2012, 8:141  doi:10.1186/1746-6148-8-141

Published: 21 August 2012

Abstract

Background

Ophthalmic antibiotic therapy in large animals is often used empirically because of the lack of pharmacokinetics studies. The purpose of the study was to determine the pharmacokinetics of topical tobramycin 0.3% ophthalmic solution in the tears of normal horses using an automated immunoassay analysis.

Results

The mean tobramycin concentrations in the tears at 5, 10, 15, 30 minutes and 1, 2, 4, 6 hours after administration were 759 (±414), 489 (±237), 346 (±227), 147 (±264), 27.6 (±28.4), 14.8 (±66.6), 6.7 (±18.6), and 23.4 (±73.4) mg/L. Mean tobramycin concentration was maintained above the MIC90 for commonly isolated bacteria for 68.5 min.

Conclusion

A single dose of topical tobramycin resulted in therapeutic concentrations of tobramycin in the tears for 1 h after administration. Therapeutic levels of tobramycin remained in equine tears 6 times longer than was reported in rabbit tears.

Keywords:
Antibiotic; Equine; Pharmacokinetics; Tear; Tobramycin; Topical; Ophthalmology