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': 'Anaesthetic agent contraindicated in porphyria – a) Thiopentoneb) Propofolc) Ketamined) Etomidale e) Methadone \nSelect and explain. \nA. ad, B. c, C. ac, D. ab', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Barbiturates (Thiopentone) are absolutely contraindicated in prophyria.\n\nNote : Reports about safety of etomidate in prophyria are conflicting. Some books (Miller 7th /e p. 1115) consider it\xa0safe and other books (Lee, Wylie) consider it unsafe.', 'role': 'assistant'}]