Which safety warning should patients observe with nitroglycerin therapy?

• A. Increase in protein intake
• B. Limit sleep
• C. Avoid sunlight
• D. Alcohol use should be avoided

Answer: (D)

The safety warning being tested is the interaction that can cause dangerous low blood pressure when nitroglycerin is used with substances that dilate vessels. Alcohol can enhance nitroglycerin’s vasodilating effects, leading to dizziness, lightheadedness, fainting, or falls from a sudden drop in blood pressure. Because of this, patients are advised to avoid alcohol while taking nitroglycerin.

Other options don’t reflect a direct safety warning for nitroglycerin therapy: increasing protein intake and limiting sleep aren’t related to nitroglycerin's safety profile, and avoiding sunlight is more about storing the medication to preserve potency rather than a daily safety precaution to observe during therapy.