Most cardiotoxic local anaesthetic is?

Ans. is 'a' i.e., Bupivacaine Bupivacaine (Sensoricaine, Marcaine) Bupivacaine is 2nd most commonly used local anaesthetic (after lidocaine). Bupivacaine has the highest local tissue irritancy amongst local anaesthetics. It is the most cardiotoxic local anaesthetic. Levobupivacaine (The S(-) enantiomer of bupivacaine) is less cardiotoxic and less prone to cause seizure. o Concentrations used for bupivacaine are : - Nerve block : 0.5%, Epidural : 0.25 - 0.5 %, and spinal : 0.5%. o Maximum safe dose is 2 mg/kg without adrenaline and 3mg/kg with epinephrine.