Antiangina drugs are medicines that relieve the symptoms of angina pectoris (severe chest pain). The dull, tight chest pain of angina occurs when the heart muscle is not getting enough oxygen. By relaxing blood vessels, antiangina drugs reduce the heart's work load and increase the amount of oxygen-rich blood that reaches the heart. These drugs come in different forms, and are used in three main ways.

Taken regularly over a long period, some antiangina medicines reduce the number of angina attacks. Others are taken just before some activity that usually brings on an attack, such as climbing stairs, to prevent attacks. The third type is taken when an attack begins to relieve the pain and pressure. Not every type of antiangina drug can be used in every way. Some work too slowly to prevent attacks that are about to begin or to relieve attacks that have...