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': "Which of the following doesn't worsen angina \nSelect and explain. \nA. >Sumatriptan, B. >Oxyfedrine, C. >Dipyrickuriole, D. >Thyroxine", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Oxyfedrine Drugs that exacerbate angina : Alpha blocker Beta blockers withdrawl Ergotamine Excessive thyroxine Hydralazine Methysergide Minoxidil Nifedipine Oxytocin Sumatriptin\' Vasopressin Dipyridamole - Dipyridamole is a vasodilator. It was originally developed as an antianginal agent. But it tends to worsen angina due to "coronary steal" phenomenon. Oxyfedrine - Oxyfedrine was found to depress the tonicity of coronary vessels, increase the coronary circulation volume, the oxygen uptake by the hea and also to exe a positive inotropic and chronotropic action. - It does not precipitate angina. - In fact it is used as an antianginal drug.', 'role': 'assistant'}]