Which is an expected side effect of nitroglycerin administration?

• A. Headache
• B. Cool, clammy skin
• C. Hypertension
• D. Bradycardia

Answer: (A)

Nitroglycerin is a vasodilator that mainly relaxes veins, which lowers the heart’s preload and reduces myocardial oxygen demand. A classic and very common side effect comes from dilation of cerebral vessels, which produces headaches. This headache reflects the widespread vasodilation produced by the drug rather than a problem with the heart itself.

The other options don’t fit as typical side effects: cool, clammy skin would suggest poor perfusion or shock rather than the vasodilatory effect of nitroglycerin; hypertension would be opposite to what nitroglycerin does (it lowers blood pressure); bradycardia is not expected because nitroglycerin often triggers reflex tachycardia as blood pressure falls.