Nitroglycerin: Explosive History, Medical Vasodilator

Nitroglycerin (glyceryl trinitrate, GTN) is a highly explosive liquid (C₃H₅N₃O₉, MW 227.08) first synthesized by Ascanio Sobrero (1847). Alfred Nobel stabilized it as dynamite (1867).

Medical Use

Potent venous > arterial vasodilator; reduces preload & afterload, decreases myocardial O₂ demand, dilates coronary arteries.

• Angina pectoris: Sublingual tablet/spray (0.3–0.4 mg) aborts attack in 1–3 min.
• Acute heart failure: IV infusion reduces pulmonary congestion.
• Prophylaxis: Transdermal patch/ointment for chronic stable angina.

Key Points

• Rapid tolerance with continuous exposure → nitrate-free interval (10–14 hrs/day) needed.
• Contraindicated with PDE5 inhibitors (sildenafil etc.) → severe hypotension.
• Side effects: headache, hypotension, reflex tachycardia, flushing.
• Store in dark glass, cool; replace every 6 months (tablets lose potency).

From Nobel’s dynamite to life-saving cardiac drug—one of medicine’s great repurposings.