<prompt> Most commonly used local anaesthetics ?DibucaineBupivacainePrilocaineTetracaine  <response>: Ans. is b i.e., Bupivacaine Bupivacaine 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. Concentrations used for bupivacaine are : - Nerve block : 0.5, Epidural : 0.25 - 0.5 , and spinal : 0.5. Maximum safe dose is 2 mgkg without adrenaline and 3mgkg with epinephrine 