A simple dried blood spot assay for therapeutic drug monitoring of lamotrigine

Blood spot collection cards can be easily used to obtain specimens for analysis of drugs for the purpose of therapeutic drug monitoring. In this work, the development and validation of a simple technique for the determination of lamotrigine from dried blood spots is described. The method is based on liquid chromatography with ultraviolet detection. The intra-and inter-day precision (measured by CV%) was less than 11%. The accuracy (measured by relative error %) was less than 12%. The limits of detection and quantification were calculated to be 0.12 and 0.2 μg mL^-1 respectively. The small volume of blood required (10 μL), the short analysis time (less than 4 min), combined with the simplicity of the analytical technique makes this a useful procedure for monitoring lamotrigine concentrations. Our preliminary experience with the developed method indicated that it can be implemented in routine clinical setting.