This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'Upper dose limit of lignocaine in a 70 kg adult is \nSelect and explain. \nA. 100 mg, B. 150 mg, C. 200 mg, D. 250 mg', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Few common local anaesthetic drugs Name Maximum dose Comments Lignocaine 3 mg/kg (7 mg/kg with adrenaline) Early onset, sho acting, good sensory block Bupivacaine 2 mg/kg Long lasting, more cardio toxic, must never be used intravenously Prilocaine 6mg/kg (9 mg/kg with adrenaline) Least systemic toxicity, causes methemoglobinemia) Ropivacaine 3-4 mg/kg Less cardio toxic, greater sensory-motor seperation Levobupivacaine 2mg/kg Isomer of Bupivacaine with fewer cardio toxic propeies Ref: Bailey and love 27th edition Pgno : 273', 'role': 'assistant'}]