<prompt> Most cardiotoxic local anaesthetic isBupivacaineProcainePrilocaineDibucaine  <response>: Bupivacaine Sensoricaine, MarcaineBupivacaine is 2nd most commonly used local anaesthetic after lidocaineBupivacaine has the highest local tissue irritancy amongst local anaestheticsIt is the most cardiotoxic local anaestheticLevobupivacaine The S- enantiomer of bupivacaine is less cardiotoxic and less prone to cause seizureConcentrations used for bupivacaine are:- Nerve block: 0.5, epidural: 0.25 -0.5, and spinal: 0.5Maximum safe dose is 2mgkg without adrenaline and 3mgkg with epinephrine Refer: stoeltings pharmacology and physiology in anaesthetic practice, 5th edition, pg no.294 