Background/aims: The aim of this study was to evaluate the relationship between plasma elimination of lidocaine and monoethylglycinexylidide (MEGX) formation, which is considered to be a quantitative liver function test.
Methodology: The study included ten healthy subjects and 54 patients: 27 with chronic hepatitis and 27 with cirrhosis. Lidocaine and MEGX were measured at 0, 2, 5, 10, 15, 30 min and then every 30 min for 180 min using the TDX system.
Results: In cirrhotic patients, the lidocaine half-life of the slow decline phase of the plasma disappearance curve (beta-HL) and the lidocaine half-life of hepatic elimination from the second compartment (K20-HL) proved to be significantly abnormal, as did all parameters of MEGX formation. In chronic hepatitis, both the lidocaine kinetics and the MEGX formation parameters were within the normal range. In chronic hepatitis patients, MEGX formation (AUC 0-180) was significantly correlated to K20-HL (rs = -0.633, p < 0.001) and to the rapid decline phase of the plasma disappearance curve (alpha-HL, rs = -0.483, p < 0.05). In cirrhotic patients, MEGX was significantly correlated to K20-HL (rs = -0.423, p < 0.05) and to beta-HL (rs = -0.500, p < 0.01).
Conclusions: These results show that in chronic active hepatitis, MEGX formation from lidocaine is maintained as a metabolic process, whereas it is altered in cirrhotic patients. The interrelationship between lidocaine elimination and MEGX formation were somewhat different in the two liver diseases.