The nurse is teaching a client who receives nitrates for the relief of chest pain. Which of the following instructions should the nurse emphasize（）
A. Repeat the dose of sublingual nitroglycerin every 15 minutes for three doses.
B. Store the drug in a cool, well-lit place.
C. Lie down or sit in a chair for 5 to 10 minutes after taking the drug.
D. Restrict alcohol intake to two drinks per day.
参考答案：C
解析：
Nitrates act primarily to relax coronary smooth muscle and produce vasodilation. They can cause hypotension, which makes the client very dizzy and weak. Nitrates are taken at the first sign of chest pain and before activities that might induce chest pain. Sublingual nitroglycerin is taken every 5 minutes for three doses. If the pain persists, the client should seek medical assistance immediately. Nitrates must be stored in a dark place in a closed container. Sunlight causes the medication to lose its effectiveness. Alcohol is prohibited because nitrates may enhance the effects of alcohol.