Urinary metabolites of chloroprocaine studied by combined gas chromatography--mass spectrometry.

The purpose of this study was to identify the metabolic pathway of 2-chloro-4-aminobenzoic acid (CABA), a primary metabolite of chloroprocaine. Urine was collected from 4 healthy, pregnant women following the epidural administration of 600 mg chloroprocaine. The urinary metabolites were extracted with ether and identified and quantitatively estimated with a gas chromatography--mass spectrometry instrument. The analysis showed that CABA is converted to N-acetyl-CABA and subsequently excreted in the urine.