Pharmacokinetic behavior of marbofloxacin after intravenous, subcutaneous and intramuscular administrations in llamas (Lama glama)

The purpose of this study was to determine the pharmacokinetic profile of marbofloxacin in llamas following single IV, IM and SC administration of 5 mg/kg bw. To assess whether these routes could be an option for the administration of marbofloxacin in this specie and estimate efficacy predictors (PK/PD) from bibliographic MIC90 values. The principal pharmacokinetic parameters were Vss = 0.72 ± 0.22 L/kg, Cl = 0.09 ± 0.03 L/kg h (for IV administration), Cmax = 7.43 ± 1.28 μg/mL and 6.94 ± 2.19 μg/mL for IM and SC administration, respectively; t1/2λ = 9.16 ± 1.08 h, 8.47 ± 0.31 h and 6.26 ± 0.87 h and MRT = 7.30 ± 1.07 h, 8.21 ± 1.57 h and 8.27 ± 0.96 h for IV, IM and SC administrations, respectively. The values obtained for the pharmacokinetic parameters were not significantly different among routes of administration except Cmax, Vz and t1/2λ. The values obtained from the PK/PD indices were Cmax/MIC90 (12.4–32.3) and AUC0–24/MIC90 (105.7–178.52 h); taking into account these values, it was concluded that a IM or SC dose of 5 mg/(kg day) of marbofloxacin would be adequate in treating infections caused by susceptible bacteria with MIC < 0.44 μg/mL.