Assessment of monoethylglycinexylidide as measure of liver function for patients with chronic viral hepatitis.

The liver metabolizes lidocaine by oxidative deethylation to form monoethylglycinexylidide (MEGX), an analyte proposed as an index of liver function. We determined MEGX and lidocaine serum concentrations with the TDx (Abbott Laboratories) at baseline and 15, 30, 60, and 90 min after the intravenous administration of lidocaine (1 mg/kg), analyzing specimens from 12 apparently healthy volunteers and 40 patients with chronic viral hepatitis diagnosed by liver biopsy and serum tests. The patients were grouped on the basis of the histology activity index. The following laboratory tests were performed on serum specimens from all subjects: albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, total bilirubin, and prothrombin time. The results showed no significant difference among the four groups for the concentrations of MEGX, lidocaine, and lidocaine/MEGX at the four time points. However, the concentrations of ALB, ALT, AST, AST/ALT, and prothrombin time were substantially different among the four groups. Thus, we conclude that assay of MEGX in our patients with chronic viral hepatitis did not contribute to the assessment of liver function when compared with apparently healthy volunteers and traditional tests of liver function.