Which of the following is a common adverse effect of nitroglycerin?

• A. Hypotension
• B. Hyperkalemia
• C. Hyperglycemia
• D. Tachycardia

Answer: (A)

Nitroglycerin works by dilating vascular smooth muscle, with a stronger effect on veins than arteries. This venodilation reduces venous return to the heart (preload) and can lower systemic vascular resistance, leading to a drop in blood pressure. That BP decrease is the most consistent and expected adverse effect you’ll see with this drug. It often comes with headaches and dizziness from cerebral vasodilation. A reflex increase in heart rate can occur as the body tries to compensate for the lower blood pressure, but the primary concern is hypotension. Hyperkalemia and hyperglycemia aren’t related to nitroglycerin’s action, so they’re not expected adverse effects.