Pharmacokinetics of oleandomycin in dogs after intravenous or oral administration alone and after pretreatment with metamizole or dexamethasone

The pharmacokinetics of oleandomycin (OLD) after intravenous and oral administration, both alone and after intramuscular pretreatment with metamizole or dexamethasone, were studied in healthy dogs. After intravenous injection of OLD alone (10 mg/kg as bolus), the elimination half-life (t(1/2 beta), volume of distribution (V-d,V-area), body clearance (Cl-B) and area under the concentration-time curve (AUC) were 1.60 h, 1.11 L/kg, 7.36 (ml/kg)/min and 21.66 mug h/ml, respectively. There were no statistically significant differences following pretreatment with metamizole or dexamethasone. After oral administration of OLD alone, the t(1/2 beta), maximum plasma concentrations (C-max), time of C-max (t(max)), mean absorption time (MAT) and absolute bioavailability (F-abs) were 1.68 h, 5.34 mug/ml, 1.5 h, 1.34 h and 84.29%, respectively. Pretreatment with metamizole caused a significantly decreased value for C-max (2.93 mug/ml) but the MAT value (2.23 h) was significantly increased. Statistically significant changes in the pharmacokinetic parameters of OLD following oral administration were also observed as a result of pretreatment with dexamethasone. The C-max was increased (8.24 mug/ml) and the t(max) (0.5 h) and MAT (0.45 h) were lower.