Comparison of lidocaine by fluorescence polarization immunoassay, enzyme immunoassay, and high resolution gas chromatography.

Lidocaine levels in plasma for therapeutic monitoring purposes were compared by using fluorescence polarization immunoassay (Abbott TDx), enzyme immunoassay (EMIT-Cad), and a high-resolution gas chromatography (HRGC). The two immunoassay methods on 29 clinical samples gave excellent correlation (r = 0.998 and 0.999 for TDx and EMIT, respectively), when compared to the HRGC method.