单选题 A client with coronary artery disease reports intermittent chest pain that occurs with exertion. The physician prescribes sublingual nitroglycerin. When teaching the client about nitroglycerin administration, the nurse should include which instruction ？（）

A、 "Be careful after taking nitroglycerin because it may cause dizziness. "
B、 "Make sure you replace your nitroglycerin tablets every 6 months to ensure potency. "
C、 "A burning sensation after taking nitroglycerin indicates medication potency. "
D、 "When you experience chest pain, take one tablet every 30 minutes until the pain is relieved. "

【正确答案】 A

【答案解析】Clients should use caution when taking nitroglycerin because it commonly causes orthostatic hypotension and dizziness. The client should rise slowly and lie down at the first sign of dizziness. To ensure potency, store nitroglycerin in a tightly closed container in a cool, dark place and replace the tablets every 3 months. Many brands of nitroglycerin no longer cause a burning sensation. The client should take a sublingual nitroglycerin tablet at the onset of chest pain and repeat the dose every 5 to 10 minutes, for up to 3 doses. If this doesn't relieve chest pain, the client should seek immediate medical attention.