Doxycycline pharmacokinetics in geese

Funding Information: This work was supported by University of Pisa (ex 60%). The authors acknowledge ThothPro (Gdansk, Poland) for supplying the software used for the pharmacokinetic analysis. The authors are grateful to Mr. Zbigniew Kołodziej (Majątek Rutka, Puchaczow, Poland) for assistance conducting animal experiment and for supplying animals and facilities. The authors sincerely thank Dr. Victoria Llewelyn (Flinders University, Australia) for the scientific and English editing of the manuscript. Funding Information: This work was supported by University of Pisa (ex 60%). The authors acknowledge ThothPro (Gdansk, Poland) for supplying the software used for the pharmacokinetic analysis. The authors are grateful to Mr. Zbigniew Ko?odziej (Maj?tek Rutka, Puchaczow, Poland) for assistance conducting animal experiment and for supplying animals and facilities. The authors sincerely thank Dr. Victoria Llewelyn (Flinders University, Australia) for the scientific and English editing of the manuscript. Publisher Copyright: © 2021 The Authors. Journal of Veterinary Pharmacology and Therapeutics published by John Wiley &Sons Ltd.The study aims to describe the pharmacokinetics of doxycycline after a single intravenous and oral dose (20 mg/kg) in geese. In addition, two multiple-dose simulations have been performed to investigate the predicted plasma concentration after either a 10 or 20 mg/kg daily administration repeated consecutively for 5 days. Ten geese were enrolled in a two-phase cross-over study with a washout period of two weeks. All animals were treated intravenously and orally with doxycycline, and blood samples were collected up to 48 h after drug administration. Sample analysis was performed using a validated HPLC-UV method. A non-compartmental approach was used to evaluate the pharmacokinetic parameters of the drug. A long elimination half-life was observed (13 h). The area under the curve was statistically different between the two treatments, with the oral bioavailability being moderate (43%). The pharmacokinetic/pharmacodynamic index (%T>MIC) during the 48 h treatment period in the present study (71%) suggests that doxycycline appears to have therapeutic efficacy against some Mycoplasma species in the goose. The multiple-dose simulations showed a low accumulation index. A dosage of 10 mg/kg/day for 5 days seemed to be adequate for a good therapeutic efficacy without reaching unnecessarily high plasma concentrations.publishersversionPeer reviewe