Angina refers to chest pain or pressure. Caused by inadequate oxygenation of the heart, angina typically results from some level of blockage and narrowing within the coronary arteries. Clinicians at the Mayo Clinic refer to the two main types as chronic stable angina and unstable angina. During chronic stable angina, rest relieves the pain. In contrast, unstable angina continues or worsens with rest. Unstable angina may signal an imminent heart attack and should be treated as an emergency. Physicians rely on several classes of drugs to treat angina medically.
Antiplatelets
As the name suggests, this class of drugs prevents excess formation of platelets, or clots, in the blood. Clots are especially dangerous for patients who have narrowed arteries. Aspirin is the most common antiplatelet and, according to the Merck Manual, it is often prescribed in combination with a second antiplatelet drug.
Beta Blockers
Beta blockers inhibit the hormone epinephrine, also known as adrenaline. Beta blockers cause the heart to beat more slowly and less forcefully, reducing blood pressure. Beta blockers also cause blood vessels to relax and dilate, which improves blood flow to the heart.
Calcium Channel Blockers
This drug class produces many of the same effects as the beta blockers, but it achieves these results by targeting cardiac calcium. Arteries widen to improve blood flow, pulse slows and the workload on the heart is reduced. Calcium channel blockers work very effectively when high blood pressure is also present.
Angiotensin-converting Enzyme (ACE) Inhibitors
As the Merck Manual explains, this drug class inhibits an enzyme that produces a chemical called angiotensin II. This chemical affects the heart by causing arteries to narrow, which in turn increases blood pressure and causes the heart to work harder.
Statins
Statins work by blocking a substance the body needs to produce cholesterol, which can accumulate on artery walls. Statins may also help reduce blockage in the arteries by causing reabsorption of existing cholesterol by the body.
Nitrates
Nitrates dilate blood vessels and increase blood flow. The most common form of nitrate, nitroglycerin, is taken orally by dissolving the tablet under the tongue. According to the Merck Manual, nitroglycerin begins to act within a minute or two, and the effects may last up to 30 minutes. Longer acting nitrates can be taken orally or with a skin patch.
