<prompt> Most cardiotoxic local anesthetic agent is?LignocaineProcaineMepivacaineBupivacaine  <response>: Ans is d i.e. Bupivacaine Bupivacaine is the most cardiotoxic local anesthetic. Levobupivacaine The S- enantiomer of bupivacaine is less cardiotoxic and less prone to cause seizure.Other important information about Bupivacaine Sensoricaine, Marcaine Bupivacaine is 2nd most commonly used local anesthetic after lidocaine. Bupivacaine has the highest local tissue irritancy amongst local anesthetics. Concentrations used for bupivacaine are : - Nerve block : 0.5, Epidural: 0.25 - 0.5 WB 98 and spinal : 0.5. Maximum safe dose is 2 mgkg without adrenaline and 3mgkg with epinephrine. 