A patient with angina is being discharged with a prescription for nitroglycerin sublingual tablets. Which instruction should the nurse include?

A. "Store the tablets in the original dark container and tightly close it after use.": Nitroglycerin is sensitive to light, heat, and moisture, which can reduce its potency. The original amber-colored glass container protects the medication and must be tightly sealed to maintain stability and effectiveness. B. "The tablets are only good for 1 week after the container is opened.": While nitroglycerin tablets do degrade over time, they remain effective for about 6 months after opening if stored properly. A 1-week expiration is inaccurate. C. "Sublingual nitroglycerine tablets are also effective when swallowed as a whole.": Swallowing the tablet bypasses the sublingual route and leads to first-pass metabolism in the liver, significantly reducing the medication’s effectiveness in relieving acute anginal attacks. D. "Effects of sublingual nitroglycerin begin in 5–10 minutes.": Nitroglycerin works rapidly, typically within 1 to 3 minutes when taken sublingually. A 5–10 minute onset is too delayed and may mislead the patient in recognizing when the drug should take effect.