ABSTRACT
Nursing mothers are occasionally treated with intravenous lidocaine for ventricular dysrhythmias. There have been no reports on the excretion of lidocaine into breast milk. This case documents the excretion of lidocaine into breast milk in small amounts and shows the validity of the TDx methodology used in the whole-milk lidocaine assay. We observed breast-milk concentrations of lidocaine at 40 percent of the serum levels. Clinical practitioners should be aware the lidocaine is excreted into breast milk in small amounts and the mother could probably continue to safely breast-feed her child while on parenteral lidocaine. Any adverse reactions in the nursing infant would probably be limited to an idiosyncratic or allergic reaction.
Subject(s)
Lidocaine/metabolism , Milk, Human/metabolism , Adult , Female , Humans , Kinetics , Spectrometry, FluorescenceABSTRACT
Three women, aged 27, 33, and 35 years, experienced recurrent syncope five months after losing 36 to 41 kg using liquid protein diets. No abnormalities were noted during physical examination except in one who was hypothyroid. Serum potassium levels varied between 2.9 and 3.9 mEq/liter. The ECGs demonstrated prominent U waves, QUc prolongation, and ST and T wave abnormalities, with left axis deviation in two patients. Syncopal episodes were due to ventricular tachycardia and fibrillation, which were not responsive to conventional antiarrhythmic agents used in two patients. Patients using liquid protein diets may thus experience reversible QUc prolongation giving rise to serious arrhythmias that are probably best treated with drugs that shorten the QTc interval. Caution should be exercised in the use of liquid protein diets for weight reduction in obesity.
