Medications Anti-clotting medications: This includes aspirin and other blood-thinning medicines. Nitroglycerin: This medicine is used to relieve chest pain. It also is a powerful vasodilator, meaning it causes blood vessels to widen so blood can pass through more easily. Thrombolytic (clot-busting) medications: These intravenous (IV) medications cause blood clots to break down and dissolve. These medications are usually used only within the first 12 hours after a heart attack. Anti-arrhythmia medications