Lidocaine, monoethylglycinexylidide, and isolated human uterine muscle

The effects of lidocaine and its primary metabolite monoethylglycinexylidide (MEGX) on isolated human muscle strips from non-gravid and gravid uteri were evaluated. No differences between the effects of lidocaine and those of MEGX on gravid and non-gravid muscle strips were observed. Lidocaine produced significant (P less than 0.01) dose-related depression of uterine contractility, although significant pharamacologic depression occurred only at lidocaine concentrations in excess of 25 microgram/ml. MEGX produced no consistent changes in any of the responses measured.