title: The low-dose monoethylglycinexylidide test: assessment of liver function with fewer side effects.
abstract: The hepatic metabolism of lidocaine (1 mg/kg intravenously) to its metabolite monoethylglycinexylidide (MEG-X) is the basis of the standard MEG-X test. To reduce the lidocaine-induced side effects, we evaluated the MEG-X formation after 0.5 and 1 mg/kg lidocaine intravenously in subjects with normal (n = 5) and severely impaired liver function (n = 7) (study I). From this study, a low-dose test (MEG-X concentration 30 minutes after 50 mg lidocaine intravenously [MEG-X30min] normalized to standard MEG-X test results) was developed. Sensory side effects from this low dose and from the standard MEG-X test were compared in a double-blind, randomized, cross-over study (study II) comprising 15 individuals with normal liver function and 45 patients with cirrhosis (15 Child A, 15 Child B, and 15 Child C). In study I, MEG-X formation rate was dose-independent in patients with severely impaired liver function. In study II, normalized MEG-X test results (ranging from < or = 4 to 120 microg/L) were virtually identical to the standard test results (mean difference: -1.9 microg/L; 95% confidence interval [CI]: -5.3; 1.5 microg/L). Fewer individuals experienced side effects (30% vs. 53%) with the low-dose test (P = .0013). In a multivariate analysis, the Child-Pugh score was inversely related to the occurrence of side effects. The low-dose MEG-X test gives almost identical results to the standard MEG-X test and is associated with fewer side effects, which occur less often in individuals with more severely compromised liver function.
authors.affiliation: Department of General Internal Medicine, University of Bonn, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Reichel
authors.forename: A
authors.initials: A
authors.lastname: Nacke
authors.forename: T
authors.initials: T
authors.lastname: Sudhop
authors.forename: G
authors.initials: G
authors.lastname: Wienkoop
authors.forename: C
authors.initials: C
authors.lastname: Lüers
authors.forename: C
authors.initials: C
authors.lastname: Hahn
authors.forename: C
authors.initials: C
authors.lastname: Pohl
authors.forename: U
authors.initials: U
authors.lastname: Spengler
authors.forename: T
authors.initials: T
authors.lastname: Sauerbruch
mesh_terms: D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008012:Lidocaine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D008099:Liver / Q000378:metabolism; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000378:metabolism; D017093:Liver Failure / Q000175:diagnosis* / Q000378:metabolism; D008111:Liver Function Tests / Q000009:adverse effects / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values
chemical_list: D008012:Lidocaine; C001173:monoethylglycinexylidide