Analytical techniques for measuring concentrations of therapeutic drugs in biological fluids

Abstract

Different types of assays are used in clinical laboratories for determination of concentrations of various drugs in biological fluids for therapeutic drug monitoring. Historically, concentrations of various anticonvulsants such as phenytoin, carbamazepine, phenobarbital, and primidone in serum or plasma were measured using gas chromatography (GC) or high-performance liquid chromatography. Later, these assays were replaced by immunoassays because of automation as well as need for faster turnaround time. Minimal or no specimen pretreatment is needed for analysis of various drugs in sera using immunoassays. However, immunoassays are not available for all drugs monitored in clinical laboratories, for example lamotrigine, protease inhibitors, and new generation of anticonvulsants. For analysis of these drugs, GC, HPLC, or HPLC combined with tandem mass spectrometric techniques are used. © 2008 Humana Press Inc.