A simple high-performance liquid chromatographic method for detection of hydroxyzine in human plasma after overdose. 
Hydroxyzine, a piperazine H1-receptor antagonist, is effective in generalised anxiety disorder.  For toxicological purposes, a simple reversed-phase high-performance liquid chromatographic assay was developed for the detection of hydroxyzine in human plasma.  A liquid-liquid procedure was used to extract the drug from plasma in the presence of an internal standard (clothiapine).  The analysis was performed on a Spherisorb S5 C(8) analytical column with UV detection.  A linear response was observed over the concentration range 20-1500 ng/ml.  A good accuracy (bias<7.3%) was achieved for all quality controls, with intraday and interday variation coefficients inferior to 8.5%.  The limit of detection was 10 ng/ml, without interference of endogenous components.  This rapid method (run time<13 min) is currently used for poison management involving hydroxyzine.