LC–MS/MS as a tool for TDM services: Where are we?

• This article provides an overview of the current use of LC–MS/MS methods for TDM services.
• It discuss both the advantages and challenges when using LC–MS/MS for TDM.
• It summarizes ongoing issues of LC–MS/MS for TDM.
• It provides an outlook on new perspectives of the application of LC-MS/MS in the field of TDM.

Therapeutic Drug monitoring (TDM) is a multidisciplinary endeavor encompassing skills of the laboratory, clinical pharmacologists and physicians aimed at providing the best possible patient care via the individualization of drug therapy. The expanding role of liquid chromatography - tandem mass spectrometry (LC–MS/MS) in TDM is based on dramatic improvements in analytical instrumentation, thereby enabling unique specificity, extreme sensitivity, high throughput, the simultaneous analysis of multiple drugs and metabolites in a drop of blood within several minutes and the use of multiplexed platforms for the rapid determination of single analytes. However, analysis by LC–MS/MS does not automatically ensure reliable results and superiority over other assays. The aim of this article is to provide an overview of the current use, advantages, and challenges of LC–MS/MS methods in TDM services, to summarize ongoing issues, and to provide an outlook on new perspectives.