Arbekacin: another novel agent for treating infections due to methicillin-resistant Staphylococcus aureus and multidrug-resistant Gram-negative pathogens
- Tetsuya Matsumoto
- Clinical pharmacology : advances and applications
Antibiotic levels in serum are commonly used to guide antibiotic therapy. The antibiotic levels in peripheral lymph are a more accurate reflection of the efficacy of antibiotic penetration into the tissues of patients with complicated skin and soft-tissue infections. The pharmacokinetics of arbekacin sulfate (ABK) in peripheral lymph after systemic administration has not been studied. Four patients (cases 1-4) with skin and soft-tissue infections (average age 74.3 years, range 54 to 85) received 200 mg of ABK intravenously once a day either by slow bolus (5min.) or by slow infusion (60 min.). The serum concentrations collected 60min. after the start ofABK infusion (C60) and the peripheral lymph concentrations of ABK were measured. 55 min. after initiation of slow 5-min. bolus (case 1), C60 was 32.5l microg/mL. The daily average concentration of ABK in peripheral lymph after slow bolus (case 1) was 14.84 microg/mL. The ratio peripheral lymph on daily average/C60 was 0.46. Patients (cases 2, 3 and 4) had been intravenously administered ABK at an infusion time of 60 min. C60 (cases 2, 3 and 4) were 14.10, 11.48 and 8.26 microg/mL, respectively. The daily average concentration of ABK in peripheral lymph after slow infusion (case 2) was 7.80 microg/mL. The average concentrations of ABK in peripheral lymph during the third eight hours since slow infusion (cases 3 and 4) were 0.72 and 2.23 microg/mL. The ratio peripheral lymph/C60 was 0.55, 0.06 and 0.27, respectively. An increase in the serum peak concentration of ABK may lead to considerable elevation of the concentration of ABK in peripheral lymph.