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Maternal, fetal, and neonatal metabolism of lidocaine
Author(s) -
Kuhnert Betty R.,
Knapp Daniel R.,
Kuhnert Paul M.,
Prochaska Anne L.
Publication year - 1979
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt1979262213
Subject(s) - lidocaine , medicine , fetus , umbilical cord , urine , anesthesia , population , metabolism , drug metabolism , venous blood , pregnancy , endocrinology , biology , environmental health , anatomy , genetics
We investigated the metabolism of lidocaine to its active metabolites—monoethylglycinexylidide (MEGX) and glycinexylidide (GX)—in the mother, fetus, and neonate. The study population included normal patients and their infants delivered either vaginally or by cesarean section. A group of infants of mothers in whom pudendal anesthesia was induced was also included. Using gas chromatography and mass spectrometry techniques, the concentrations of lidocaine, MEGX, and GX were determined in maternal plasma during labor, in umbilical cord venous and arterial plasma at delivery, and in maternal and neonatal urine for 3 days post partum. The results indicate the following: In maternal plasma, MEGX rises throughout labor and GX is usually detectable within an hour of medication: in cord blood plasma the levels of lidocaine, MEGX, and GX suggest fetal metabolism of lidocaine; and in neonatal urine, the relative levels of parent compound and metabolites confirm lidocaine metabolism by the neonate.