This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
[{'content': "Laudanosine is metabolite of aEUR' \nSelect and explain. \nA. >Cisatracurium, B. >Atracurium, C. >Pancuronium, D. >Gallamine", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Atracurium > Cisatracurium Laudanosine (teiary amine) is a metabolite of both Atracurium and its isomer cisatracurium. Atracurium and its isomer cisatracurium posess a unique characteristic to undergo spontaneous non enzymatic chemical breakdown at physio- logical pH and temperature (Hoffman elimination). Most of the Atracurium and cisatracuriwn is metabolized in this way. - These drugs are so extensively metabolized in this way that their phurmacokinetics is independent of renal and hepatic function. Laudanosine is a breakdown product of the spontaneous non enzymatic organ independent degradation of the drug (Hoffman elimination). -Both Atracurium and cisatracurium undergo Hoffman elimination resulting in laudanosine. - "Because of its higher potency cisatracurium produces less laudanosine than Atracurium". Laudanosine may have some potentially toxic systemic effects - It crosses the blood brain barrier and may cause excitement and seizure activity. - In C. VS. high plasma concentration, produces hypotension and bradycardia. -These are probably irrelevant considerations/side effects unless a patient has received an extremely high total dose or has hepatic .failure. - Laudanosine concentration increases in hepatic failure as it is metabolized by the liver.', 'role': 'assistant'}]