Voriconazole

In this study, eight of the most commonly used antimicrobial agents to treat specific blood stream infections were chosen. The commercially available standards of meropenem, imipenem, levofloxacin, cefoxitin, piperacillin-tazobactam, vancomycin, voriconazole (Meilunbio, China), and linezolid (Sigma, USA) were reconstituted according to the manufacturer’s instructions. The peak serum concentration (C_max), achieved according to standard dosing of the antimicrobial under the condition of a 70-kg adult with normal renal function, was used to simulate patient blood levels (Table 1). If no growth was detected, antimicrobials were then injected at concentrations of C/2 and/or C/4 to obtain positive results in any culture system. Each antimicrobial agent was diluted in sterile water from stock solutions to ensure that 0.3 mL of the dilution contained the desired final antimicrobial concentration of a blood culture bottle.

All active pharmaceutical ingredients, including LEF, fluconazole (FLC), itraconazole (ITR), and voriconazole (VRC) were purchased from Dalian Meilun Biotech Co., Ltd., Dalian, China. Solutions of LEF, ITR and VRC were prepared with ethyl alcohol. FLC solution was dissolved in sterile water. Stock solutions were stored away from light at −20 °C.