This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Histamine, 5-HT and PGs, Subject name: Pharmacology
[{'content': 'This antihistaminic drug can cause cardiac arrhythmia at high dose by blocking cardiac K+ channels. It is most likely to be: \nSelect and explain. \nA. Levo-cetrizine, B. Fexofenadine, C. Astemizole, D. Loratidine', 'role': 'user'}, {'content': "Answer: C \nExplanation: The drugs which can cause QT prolongation and Torsades' de pointes and have been withdrawn from the market due to this reason are: C: Cisapride A: Astemizole T: Terfenadine You can remember CAT is cute, so these drugs cause QT prolongation.", 'role': 'assistant'}]