Clin Chim Acta. 2020 Dec;511:360-367. doi: 10.1016/j.cca.2020.11.001. Epub 2020 Nov 5.
BACKGROUND AND AIMS: TDM of antibiotics can bring benefits to patients and healthcare systems by providing better treatment and saving healthcare resources. We aimed to develop a multi-analyte method for several diverse antibiotics using LC-MS/MS.
MATERIALS AND METHODS: Sample preparation consisted of protein precipitation with methanol, dilution and online extraction using a Turboflow Cyclone column. Separation was performed on a Synergi 4 µm Max RP column and deuterated forms of three antibiotics were used as internal standards.
RESULTS: We present a LC-MS/MS method for the quantitative determination of nine antibiotics, including five cephalosporins, the carbapenem ertapenem, the fluoroquinolone ciprofloxacin as well as the combination drug trimethoprim-sulfamethoxazole from plasma. Additionally, unbound ertapenem and cefazolin were analyzed in plasma water after ultrafiltration using plasma calibrators. Results from routine TDM show the applicability of the method.
CONCLUSION: The presented method is precise and accurate and was introduced in a university hospital, permitting fast TDM of all nine analytes. It was also used in a clinical study for measuring cefazolin free and total concentrations.