For the management of acute angina, which medication is preferred for immediate relief?

Choice A rationale Metoprolol is a beta-blocker used for long-term management of angina by reducing myocardial oxygen demand. It is not suitable for immediate relief of an acute anginal attack because its onset of action is slower than that required for rapid symptom resolution. Choice B rationale Nitroglycerin is a potent vasodilator that is the preferred medication for immediate relief of acute angina. It works by relaxing vascular smooth muscle, primarily in the veins, leading to a reduction in preload and myocardial oxygen demand, and also dilating coronary arteries. Choice C rationale Amlodipine is a long-acting calcium channel blocker used for the prevention of angina. It is not used for acute attacks because its primary effect is on chronic vasodilation and reduction of afterload, and it does not have a rapid onset of action suitable for immediate relief. Choice D rationale Aspirin is an antiplatelet agent used to prevent myocardial infarction in patients with coronary artery disease. While it is often administered during a suspected heart attack to reduce clot formation, it does not provide immediate symptomatic relief of anginal pain.