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: Pharmacology
[{'content': 'H1blocker with least sedative effect is - \nSelect and explain. \nA. Chlorpheniramine, B. Promethazine, C. Terfenadine, D. Diphenhydramine', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Terfanadine Terfanadine is a second generation antihistaminics. Advantages of second generation Antihistaminics. o Higher H1 selectivity, no anticholinergic side effects. o Absence of CNS depressant propey o Additional antiallergic mechanism apa from histamine block. o No impairment of psychomotor performance (driving etc. need not be contraindicated) o No subjective effect, No sleepiness. (Some patients complain of sedation, but the incidence is similar to placebo) o Do not potentiate alcohol or benzodiazepene", 'role': 'assistant'}]