What is a standard nitroglycerin dosing regimens for chest pain in ACS?

• A. 0.4 mg SL q5min x 3
• B. 10 mcg/min IV up to 200
• C. 0.4 mg PO
• D. 1 mg IV bolus

Answer: (A)

In acute coronary syndrome, nitroglycerin is used to relieve chest pain by dilating veins, which lowers preload and reduces myocardial oxygen demand. The standard initial regimen is sublingual nitroglycerin 0.4 mg every 5 minutes, up to a total of three doses, to rapidly address pain and ischemia. Sublingual administration provides quick onset and is practical in the ED or pre-hospital setting.

If pain persists after three doses, the next step is usually an IV nitroglycerin infusion started at a low rate (e.g., 5–10 mcg/min) and titrated to effect, with careful monitoring of blood pressure and symptoms, rather than continuing with additional SL doses.

The other options aren’t standard for acute chest pain because they either rely on slower, less reliable absorption (oral 0.4 mg) or use an IV regimen in bolus form (1 mg IV bolus) rather than a controlled infusion, which is not how acute nitro therapy is typically administered.