This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2017, Subject name: Anaesthesia
[{'content': 'The shoest acting opioid is:- \nSelect and explain. \nA. Fentanyl, B. Sulfentanil, C. Remifentanil, D. Alfentanyl', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Fentanyl : Supplemental doses are to be given after 30 min only Analogues of feentanyl * Sulfentanyl * Alfentanyl Remifentanil Onset of Action : within 1-2 min IV injection Fades in : 10-15 min Sho action is due to rapid metabolism Metabolized by : Non specific esterases( Extra hepatic,Extra renal ) Safe in fetus, can be used in labour as analgesic', 'role': 'assistant'}]