Are capillary DBS applicable for therapeutic drug monitoring of common antipsychotics? A proof of concept

Abstract

Aim: DBS sampling has been proposed as an alternative for venous blood collection in therapeutic drug monitoring (TDM) of antipsychotics. For implementation in routine practice, a comparison between capillary and venous blood concentrations is mandatory. Results: A DBS method for quantification of antipsychotics was clinically validated. First, whole blood therapeutic ranges were calculated using the blood:serum ratio. Calculation of DBS:blood ratios and Passing–Bablok regression analysis demonstrated that concentrations obtained by DBS analysis were highly comparable to those obtained by conventional whole blood analysis. Clinical interpretation of serum, whole blood and DBS concentrations were highly identical (sensitivity 91.6–97.6%). Conclusion: This is the first clinical study demonstrating the value of DBS sampling in TDM of antipsychotics.