Nitroglycerin is a medication used for anginal pain and can be administered in various routes.

• A. Epinephrine
• B. Acetaminophen
• C. Diphenhydramine
• D. Nitroglycerin

Answer: (D)

Nitroglycerin relieves anginal pain by causing vasodilation, which lowers the heart’s oxygen demand and can improve blood flow to the heart muscle. Because of this mechanism, it can be given in several routes to fit the situation and how quickly relief is needed. Sublingual tablets or sprays act fast for rapid relief, an IV infusion can be used in more controlled, hospital settings, and topical forms (paste or patch) provide longer-term management.

The other medications listed don’t address this chest pain in the same way. Epinephrine is a vasopressor used for severe allergic reactions or cardiac arrest, not for relieving stable angina. Acetaminophen reduces fever and mild pain but doesn’t affect coronary blood flow or oxygen demand. Diphenhydramine is an antihistamine for allergic symptoms and does not treat ischemic chest pain.

So, nitroglycerin is the appropriate choice because its therapeutic effect directly targets the cause of anginal pain and it can be administered through multiple routes to achieve the desired onset and duration.