Nitroglycerin is contraindicated in patients:

Nitroglycerin is contraindicated in patients:

• A. With a systolic blood pressure less than 120 mm Hg
• B. With a heart rate above 120
• C. Who are pregnant
• D. Taking aspirin

Answer: (A)

Nitroglycerin lowers blood pressure by dilating veins, which reduces preload and also can decrease afterload. When a patient’s systolic blood pressure is already low (in this context, less than 120 mm Hg), giving nitroglycerin can push the blood pressure down further and compromise perfusion to the heart and other vital organs. That risk makes it contraindicated in patients with SBP below this threshold. The other options don’t by themselves make nitroglycerin unsafe: tachycardia can occur with nitro but isn’t a blanket contraindication; nitroglycerin isn’t an absolute contraindication in pregnancy in many EMS scenarios, though it requires cautious use; and aspirin and nitroglycerin can be given together when indicated.

Nitroglycerin lowers blood pressure by dilating veins, which reduces preload and also can decrease afterload. When a patient’s systolic blood pressure is already low (in this context, less than 120 mm Hg), giving nitroglycerin can push the blood pressure down further and compromise perfusion to the heart and other vital organs. That risk makes it contraindicated in patients with SBP below this threshold.

The other options don’t by themselves make nitroglycerin unsafe: tachycardia can occur with nitro but isn’t a blanket contraindication; nitroglycerin isn’t an absolute contraindication in pregnancy in many EMS scenarios, though it requires cautious use; and aspirin and nitroglycerin can be given together when indicated.