Development of a rapid LC-MS/MS method for simultaneous quantification of ten commonly used antibiotic drugs in human serum

The use of TDM in clinical practice to monitor the plasma levels of antibiotics administered to critically ill patients is a well-established approach that allows for optimization of the patient's response to drug therapy, considering the characteristics of the drug, the clinical and physiological status of the patient and any peculiar of the pathogen that caused the clinical picture. In our laboratory, we have developed a single LC-MS/MS analysis for dosing the serum concentration of an antibacterial panel composed of eight antibacterial and two selective inhibitors. The method presented used a certified material furnished by a commercial company and was internally validated using the EMA guidelines. The results have shown high sensitivity, precision, and accuracy, a lower matrix effect combined with simple sample preparation and a time-saving procedure. We have evaluated the recovery rate and matrix effect by testing serum samples without pathological index and serum pools obtained from haemolysed, icteric, or lipemic samples. The assay has shown a recovery range between 94% and 101%.

24/7 Therapeutic Drug Monitoring of Beta-Lactam Antibiotics with CLAM-2000

BACKGROUND

The aim of this study was to evaluate the CLAM-2000 automated preanalytical sample preparation module with integrated liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) as a method for 24/7 therapeutic drug monitoring (TDM) of beta-lactam antibiotics in routine clinical diagnostics.

METHODS

Method validation was performed using quality control samples. Method comparison was performed with routine samples from patients treated with beta-lactam antibiotics.

RESULTS

The determination of piperacillin, meropenem, ceftazidime, flucloxacillin, and cefotaxime was performed using D5-piperacillin and D6-meropenem as internal standards. The linearity of the method was within the therapeutic range of beta-lactam antibiotics. The imprecision and accuracy data obtained from quality control samples were within 15%, and the imprecision of patient samples on the instrument was less than the 5% coefficient of variation (CV). Internal standards stored in the instrument at 9 °C for at least one week were stable, which facilitated reagent use and storage.

CONCLUSION

The CLAM-2000 (Shimadzu, Kyoto, Japan) provides reproducible results as an established routine instrument and is a useful tool for 24/7 TDM of beta-lactam antibiotics in routine clinical diagnostics.

Meropenem use and therapeutic drug monitoring in clinical practice: a literature review

WHAT IS KNOWN AND OBJECTIVE

Meropenem, a carbapenem antibiotic, is widely prescribed for the treatment of life-threatening infections. The main parameter associated with its therapeutic success is the percentage of time that the levels remain above the minimum inhibitory concentration. Inadequate levels of meropenem can lead to therapeutic failure and increase the possibility of microbial resistance. The employment of strategies involving dose regimens and drug pharmacodynamics has become increasingly important to optimize therapies. In the present study, we conducted a review with the purpose of assembling information about the clinical use of meropenem and therapeutic drug monitoring.

METHODS

A literature review emphasizing the application of therapeutic drug monitoring (TDM) of meropenem in clinical practice has been done. To identify articles related to the topic, we performed a standardized search from January 21, 2020 to December 21, 2020, using specific descriptors in PubMed, Lilacs and Embase.

RESULTS AND DISCUSSION

In total, 35 studies were included in the review. The daily dose of meropenem commonly ranged from 3 to 6 g/day. Critically ill patients and those with impaired renal function appear to be the most suitable patients for the application of meropenem TDM, in order to guide therapy. We observed that most of the studies recommend TDM and that, in nine locations, the TDM of meropenem and of other beta-lactams is a routine practice. TDM data can help to maximize the clinical outcomes of the treatment with meropenem. It can also improve the patient care by providing suitable levels of meropenem, guiding the most appropriate dose regimens, which is the main parameter associated with therapeutic success.

WHAT IS NEW AND CONCLUSION

The findings from this review suggest that the therapeutic monitoring of meropenem can be beneficial, since it adjusts the treatment and aids clinical outcomes. It does so by indicating the appropriate dosage and preventing failure, toxicity and possible antimicrobial resistance. The multidisciplinary effort, basic knowledge and communication among the medical team are also essential.

Personalized antibiotic therapy – a rapid high performance liquid chromatography–tandem mass spectrometry method for the quantitation of eight antibiotics and voriconazole for patients in the intensive care unit

Objectives

For a long time, the therapeutic drug monitoring of anti-infectives (ATDM) was recommended only to avoid the toxic side effects of overdosing. During the last decade, however, this attitude has undergone a significant change. Insufficient antibiotic therapy may promote the occurrence of drug resistance; therefore, the “one-dose-fits-all” principle can no longer be classified as up to date. Patients in intensive care units (ICU), in particular, can benefit from individualized antibiotic therapies.

Methods

Presented here is a rapid and sufficient LC-MS/MS based assay for the analysis of eight antibiotics (ampicillin, cefepime, cefotaxime, ceftazidime, cefuroxime, linezolid, meropenem, and piperacillin) applicated by continuous infusion and voriconazole. In addition a dose adjustment procedure for individualized antibiotic therapy has been established.

Results

The suggested dose adjustments following the initial dosing of 121 patient samples from ICUs, were evaluated over a period of three months. Only a minor percentage of the serum levels were found to be within the target range while overdosing was often observed for β-lactam antibiotics, and linezolid tended to be often underused. The results demonstrate an appreciable potential for β-lactam savings while enabling optimal therapy.

Conclusions

The presented monitoring method provides high specificity and is very robust against various interferences. A fast and straightforward method, the developed routine ensures rapid turnaround time. Its application has been well received by participating ICUs and has led to an expanding number of hospital wards participating in ATDM.