Pharmacokinetics of Tildipirosin in Healthy and Mycoplasma gallisepticum Infected Chickens

The pharmacokinetic features of tildipirosin were explored following a single dose of 4 mg/kg in healthy and Mycoplasma gallisepticum (M. gallisepticum) infected chickens. Eighteen healthy chickens (400-500g) were allocated into 3 groups (n=6); group I and II were received tildipirosin by intravenous (IV) and intramuscular (IM) routes, respectively. Group III was experimentally infected with M. gallisepticum and injected IM with tildipirosin after confirming the infection (9-10 days after inoculation of M. gallisepticum). Plasma samples were harvested at different time points until 14 days after tildipirosin injection to measure its concentrations using HPLC. After IM administration of tildipirosin in healthy chickens, the maximum concentration in plasma (Cmax), time to achieve Cmax (Tmax), area under the plasma concentration time curve from 0 to last time (AUC0-last), clearance (Cl-F-obs) and the absolute bioavailability were recorded to be 403.76ng/ml, 0.25 hr, 6.82 µg.hr/ml, 0.56L/hr/kg, and 103.50% respectively. Cmax and AUC0-last, were significantly lower in infected than healthy chickens, while Cl-F-obs was significantly higher in infected than healthy chickens. Therefore, M. gallispeticum infection produced significant changes in some of the pharmacokinetic parameters of tildipirosin in chickens. Further studies are warranted to assess pharmacokinetic/ pharmacodynamic profile of tildipirosin against M. gallisepticum in chickens and to gain deeper insight into its safety utilization in chickens.