Which one of the following drugs is most commonly employed in an attack of angina pectoris?
**Core Concept**
Short-acting nitrates are a cornerstone in the management of acute angina pectoris due to their ability to rapidly reduce myocardial oxygen demand by dilating systemic and coronary arteries, thereby increasing blood flow to the ischemic myocardium.
**Why the Correct Answer is Right**
Nitroglycerin, a nitrate compound, works by releasing nitric oxide, which activates guanylate cyclase in smooth muscle cells, leading to the production of cyclic guanosine monophosphate (cGMP). This results in the relaxation of vascular smooth muscle, causing vasodilation of both systemic and coronary arteries. This reduction in preload decreases the workload on the heart, reducing myocardial oxygen demand and alleviating angina symptoms.
**Why Each Wrong Option is Incorrect**
**Option A:** Morphine is used in the management of acute coronary syndrome but is not the first-line treatment for an attack of angina pectoris. It has analgesic and anxiolytic properties, which can help relieve symptoms, but it does not directly reduce myocardial oxygen demand.
**Option B:** Sublingual beta-blockers are not commonly used in the acute management of angina pectoris. Beta-blockers can actually worsen symptoms in the acute setting due to their negative inotropic and chronotropic effects, which can increase myocardial oxygen demand.
**Option C:** Sublingual calcium channel blockers are not typically used in the acute management of angina pectoris. While calcium channel blockers can help reduce myocardial oxygen demand by dilating coronary arteries, they are not as rapidly acting as nitrates and are not the preferred initial treatment.
**Clinical Pearl / High-Yield Fact**
In the acute management of angina pectoris, the mnemonic "Oxygen, Morphine, Aspirin, Nitrates, Beta-blockers" (OMAN) can help guide treatment decisions.
**Correct Answer:** C. Nitroglycerin.