Disposition kinetics of gentamicin following repeated parenteral administration in buffalo calves (Bubalus bubalis)

Disposition kinetics of gentamicin was determined in buffalo calves following repeated parenteral administration of 5 mg/kg body weight. The absorption (t1/2 Ka) and elimination half-life (t1/2 beta) were found to be 0.40 +/- 0.12 and 4.33 +/- 0.39 h, respectively. Statistical comparison of the values of pharmacokinetic determinants generated in this study with the corresponding values following single intramuscular injection at the same dose level as reported earlier by GARG and GARG, 1990, revealed that the consecutive administration of drug influenced the pharmacokinetics profile of gentamicin. Elimination half-life was significantly longer (P < 0.05). Since elimination rate constant value was significantly reduced, the subsequent dosage will have to be reduced particularly if kidney functions are not normal. Otherwise, dosage regimen need not be changed.