Pharmacokinetics and bone tissue concentrations of lincomycin following intravenous and intramuscular administrations to cats

Abstract

The pharmacokinetic properties and bone concentrations of lincomycin in cats after single intravenous and intramuscular administration at a dose rate of 10 mg/kg were investigated. Lincomycin minimum inhibitory concentration (MIC) for some gram-positive strains isolated from clinical cases was determined. Serum lincomycin disposition was best fitted to a bicompartmental and a monocompartmental open models with first-order elimination after intravenous and intramuscular dosing, respectively. After intravenous administration, distribution was rapid (T½ (d) 0.22±0.09 h) and wide as reflected by the volume of distribution (V(d(ss))) of 1.24±0.08 L/kg. Plasma clearance was of 0.28±0.09 L/h.kg and elimination half-life (T½) of 3.56±0.62 h. Peak serum concentration (Cmax), Tmax and bioavailability for the intramuscular administration were 7.97±2.31 µg/mL, 0.12±0.05 h and 82.55±23.64% respectively. Thirty to 45 minutes after intravenous administration, lincomycin bone concentrations were 9.31±1.75 µg/mL. At the same time after intramuscular administration, bone concentrations were 3.53±0.28 µg/mL. The corresponding bone/serum ratios were 0.77±0.04 (intravenous) and 0.69±0.18 (intramuscular). Lincomycin MIC for Staphylococcus spp ranged from 0.25 to 16 µg/mL and for Streptococcus spp from 0.25 to 8 µg/mL.