Local Anesthetic | Metabolism Repack

1. Introduction Local anesthetics (LAs) are weak bases that reversibly block voltage-gated sodium channels. While their physicochemical properties dictate onset and duration, their metabolic pathways primarily determine systemic toxicity, duration of action, and drug-drug interaction potential. Understanding these pathways is crucial for safe practice, especially in patients with hepatic disease, pseudocholinesterase deficiency, or those taking specific concomitant medications. 2. Chemical Classification Determines Metabolism The metabolic fate of a local anesthetic is almost entirely predicted by its chemical link between the lipophilic aromatic ring and the hydrophilic amine group.