What is the primary drug used to relieve angina symptoms?

Sublingual nitroglycerine is primarily used to relieve angina symptoms due to its rapid onset of action and ability to induce vasodilation. When administered sublingually, nitroglycerine is quickly absorbed into the bloodstream, providing prompt relief by widening the blood vessels and improving blood flow to the heart muscle. This makes it particularly effective during an angina attack, as it alleviates chest pain by reducing the heart's workload and oxygen demand.

Other options listed have different primary uses in medicine. Amiodarone is primarily an antiarrhythmic agent used to manage cardiac rhythm disorders. Aspirin, while it has a role in managing cardiovascular disease by inhibiting platelet aggregation, does not directly relieve angina symptoms. Calcium channel blockers may be used to help prevent angina by relaxing blood vessels and decreasing heart contractility, but they do not act as quickly as sublingual nitroglycerine during an episode. Thus, sublingual nitroglycerine is the preferred choice for immediate relief of anginal pain.