This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'A patient has been diagnosed as having "long QT syndrome." The patient is experiencing significant pain following a bout with shingles. What would be an appropriate drug for his pain? \nSelect and explain. \nA. Amitriptyline, B. Fentanyl, C. Acyclovir, D. Gabapentin', 'role': 'user'}, {'content': "Answer: D \nExplanation: It's a case of post-herpetic neuralgia. Gabapentin is the drug of choice. Amitriptyline can also be used for pain but it can also cause arrhythmia.", 'role': 'assistant'}]