ABSTRACT
Therapeutic drug monitoring (TDM) is a multidisciplinary field encompassing, among other specialities, clinical pharmacology, clinical pathology, clinical chemistry, toxicology, analytical chemistry, and medicine. The availability of TDM, in turn, is directly related to the rapid advancement in technology associated with the quantitation of drug compounds. High-pressure liquid chromatography permits simultaneous drug analysis and is a valuable tool for establishing correlations between drug and drug metabolite concentrations in biological fluids. TDM can be utilized to recognize noncompliance, compensate appropriately for individual variations in drug utilization patterns, and to identify the baseline concentrations associated with an optimal therapeutic regimen. The chapter deals with information to make decisions regarding optimal drug administration, and simple procedures for interpreting and applying the laboratory results obtained with respect to a given drug. For most drugs, the intensity and duration of a given pharmacological effect is proportional to the drug concentration at the receptor site.
