Pharmacokinetics of Doxycycline in Ducks with Steatosis due to Force-feeding

Abstract

Macedonian Veterinary ReviewThe pharmacokinetics of doxycycline was investigated in force-fed and normally fed ducks after single intravenous (i.v.) and oral (p.o.) administration at a dose of 15 mg/kg bw. Serum concentrations of the drug were determined by the HPLC method. Pharmacokinetic parameters were calculated using compartmental analysis. Serum concentrations of doxycycline after i.v. administration in both groups were not statistically different. The values of half-lives were 5.82±1.85 h and 6.06±5.51 h in normal and force-fed birds. The total body clearance was respectively 0.40±0.05 L/h/kg and 0.34±0.10 L/h/kg, and volume of distribution (V ss ) was 2.80±0.85 L/kg and 2.18±0.89 L/kg. After p.o. administraton the maximum serum levels in the control group were 0.70±0.12 μg/mL and in force-fed birds were 1.93±0.32 μg/mL, measured at 2.95±0.60 h and 1.45±0.24 h, respectively. The values of absolute bioavailability were 18.89±6.48% and 37.58±13.63%. Longer doxycycline retention in force-fed ducks was registered. Our data can be accepted as an information for possible prolonged retention of doxycycline in force fed ducks compared to normally fed ones.

Comparison of Mathematical Models for the Use of Enrofloxacin in Dogs

“…The values for R 2 , quadratic error, AIC and AICc were obtained using the identification software. The credibility of the model and the proof coefficient are calculated by formulas (3) and (4). To choose a model, the corrected version of AIC is used, as the N and K research processes are relatively close.…”

“…Enrofloxacin is an antibacterial drug from the group of fluoroquinolones for use in veterinary medicine [2,4]. In [1], the change in its blood plasma concentration in dogs was studied in three ways of drug treatment -intravenous and subcutaneous injection and internal administration.…”

Selection of the Mathematical Model for the Use of Enrofloxacin in Cats

“…To calculate the reliability of the model and the coefficient of proof are formulas (1) and (2) used. The calculations are done with Excel.…”

“…In [2] describes in detail the algebraic model used, which is a solution of a first-order differential equation.…”

“…Enrofloxacin is a broad-spectrum antibacterial drug officially registered and authorized for use in veterinary medicine. It belongs to the so-called "second generation" of fluorinated quinolones [2,3]. In [7], the change in the concentration of enrofloxacin in the blood plasma of cats was monitored by comparing the dynamic parameters of the drug's pharmacokinetics with three methods of administration.…”