This document discusses anti-anginal drugs used to treat angina pectoris. Angina is a type of chest pain due to reduced blood flow and oxygen delivery to the heart muscle. There are several types of angina including stable angina, variant angina, and unstable angina. Risk factors for angina include hypertension, high cholesterol, family history, diabetes, smoking, and lifestyle. Anti-anginal drugs fall into two main classes - vasodilators which relax blood vessels to increase blood flow, such as nitroglycerin, and calcium channel blockers which block calcium entry into heart muscle cells to relax vessels, such as nifedipine. These drugs provide relief of chest pain from angina