Pharmacokinetics of Local Anesthetics in Fascial Plane Blocks: Clinical Implications and Safety Considerations-A Narrative Review

Main Points• Fascial plane blocks (FPBs) exhibit distinct pharmacokinetics characterized by high-volume interfascial spread and clinically relevant systemic absorption, making peak plasma concentration and time to peak critical determinants of safety.• Pharmacokinetic variability is driven by the interplay between patient factors, drug properties, adjuvants, and fascial plane anatomy, necessitating individualized dosing strategies.• Systemic exposure after FPBs may approach or exceed toxicity thresholds even within conventional dose limits, highlighting the persistent risk of local anesthetic systemic toxicity.• Rational selection of drugs and adjuvants, combined with vigilant monitoring, is essential for optimizing analgesic efficacy while maintaining pharmacokinetic safety.