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: Medicine
[{'content': 'Best time to administer long term nitrates for nocturnal angina: September 2011 \nSelect and explain. \nA. Early morning, B. Noon, C. Evening, D. Late night', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Evening If nocturnal angina is a predominant symptom, long term nitrates can be given at the end of the day Nitrates: They cause vasodilation, flushing, headache, dizziness, met-hemoglobinemia Decreases preload and afterload Decreases myocardial oxygen consumption Causes reflex tachycardia, hypotension Long acting nitrates are not used chronically as tolerance develops *Shoest acting NITRITE: Amyl nitrite Shoest acting nitrate: Nitroglycerine Longest acting nitrate: Penta-erythritol-nitrate', 'role': 'assistant'}]