LC-MS/MS as versatile tool in therapeutic drug monitoring

Therapeutic drug monitoring is an interdisciplinary effort to improve patient's therapy in terms of efficacy, adverse effects, drug-drug interactions or compliance. The accurate, precise and timely determination of the drug concentration is central part of this process. Quantitation in plasma is nowadays performed predominantly using liquid chromatography hyphenated to tandem mass spectrometry (LC-MS/MS). The introduction of LC-MS/MS in clinical laboratories started in the 1990 s. The reason for its fast growing success is the combination of high sensitivity (ng/L to mg/L) and selectivity, dynamic range, and the hyphenation to liquid chromatography systems. Sample preparation can often be reduced to simple protein precipitation and dilution including suitable stable isotopically labeled standards.

The aim of this presentation is to provide an insight into the analytical technique and the processes involved in laboratory routine to determine the drug concentration in plasma.