Dried Blood Spot Analysis for Simultaneous Quantification of Antiepileptic Drugs Using Liquid Chromatography-Tandem Mass Spectrometry.

RATIONALE

Dried blood spot (DBS) sampling for the therapeutic drug monitoring of antiepileptic drugs offers practical advantages, including minimal invasiveness and ease of collection. However, for precise therapeutic management, its accuracy and reliability in quantification need to be validated.

METHODS

This study validates DBS sampling for the analysis of 11 antiepileptic drugs using liquid chromatography-tandem mass spectrometry (LC-MS/MS), overcoming the physicochemical challenges associated with DBS samples.

RESULTS

The acetonitrile-based DBS extraction method demonstrated high efficiency for the 11 antiepileptic drugs. Accuracy and precision within 6% were achieved in both intra- and inter-day assays, with good selectivity, minimal matrix effects, and negligible carryover. All antiepileptic drugs exhibited stability in DBS samples for at least 30 days at room temperature, confirming proper handling and storage of the DBS samples. A 3 mm diameter disc punched from a DBS produced accurate results for all target drugs.

CONCLUSIONS

The optimized method provided a time- and cost-effective solution, showing a strong correlation between drug concentrations in whole blood, thereby supporting the suitability of DBS sampling as a promising and advanced method for antiepileptic drug monitoring.