If you experience angina, medications are certain to be a part of your treatment. Because angina is an indication that your heart needs more oxygen (usually because of a blocked coronary artery), treatment includes drugs that either reduce your heart’s oxygen requirements or increase blood ?ow to your heart so that it gets more oxygen. The goal of treatment with medications is to prevent or ease the discomfort of this symptom.
If you have a heart attack, you may be given medications (throm- bolytic agents) at the hospital to dissolve blood clots that may have formed in an artery already clogged with plaque. This step limits the extent of damage to heart muscle and may save tissue before it is beyond repair.

Nitroglycerin

If you have angina, your doctor is likely to prescribe nitroglycerin, which is a vasodilator, meaning that it expands blood vessels to increase blood supply. Used properly, it relieves angina in as little as 2 minutes by reduc- ing the return of (depleted) blood to the heart and thereby easing its workload, and by relaxing the coronary arteries to allow more oxygen- rich blood to reach your heart. It’s important to remember that angina alone does not mean that you are having a heart
attack or that heart muscle is being damaged it is a temporary decrease in blood to the heart because of restricted supply and increased demand. Nitroglycerin provides a “quick ?x” that allows you to be more active and free of pain.
Nitroglycerin is inexpensive and not at all habit-forming. You can take it several times a day without harm. It works best if you take it at the very earliest sensation of discomfort. Better yet, doctors advise people with stable angina to learn to recognize the conditions (exertion, excitement, or deep emotion) that are likely to lead to the pain and take nitroglycerin preventively. Many people experience angina in predictable circum- stances, such as walking outdoors on a cold, windy, or humid day; carrying parcels or heavy items and hurrying; getting exercise after a heavy meal; working under deadline pressure; speaking in public; engaging in sexual activity; or feeling angry, worried, or tense. Being able to “head off ” angina or keep an episode short is an excellent way to take control of your heart condition.

If your doctor prescribes nitroglycerin, ask for directions about how to take it (see box) and talk to him or her about any concerns you have about using it. If you feel uncertain about it, ask to take a nitroglycerin tablet in your doctor’s presence. You will probably feel a slight tingling sensation under your tongue, your face may ?ush, or you may have a sensation of fullness in your head as the medication works in your blood vessels, but more troublesome side effects (light-headedness or headache) are rare. Once you are accustomed to taking nitroglycerin freely, you can derive the full bene?t of the relief it provides.

Beta-blockers

Beta-blockers (or beta-adrenergic blocking agents) are a group of drugs that reduce the heart’s workload and decrease its need for oxygen. They are commonly prescribed for angina, high blood pressure (see page 62), irregular heartbeat, cardiomyopathy (disease of the heart muscle), and heart failure. (They are also used to treat non-heart-related conditions such as migraine headaches and glaucoma.)
A beta-blocker works by interfering with the body’s natural response to stress. When your body is responding to stress, it releases hormones called catecholamines (norepinephrine and epinephrine) that stimulate an increase in heart rate, heart muscle contraction, and blood pressure. A beta-blocker diminishes the effects of the catecholamines, thereby modifying the heart’s response to stress. Numerous beta-blockers are available that act selectively on different aspects of the action of catecholamines.
If your doctor prescribes beta-blockers for angina, the effects of the drug will enable your heart to work longer during exercise or other stress before the angina occurs. You will need to take the beta-blockers daily, in addition to other drugs such as nitroglycerin. Even if you have no symptoms, doctors will often prescribe beta-blockers, since studies have shown they can reduce the risk of a second heart attack.
If you experience a heart attack, your body will produce high levels of catecholamines that cause your heart to work harder. Doctors may give you a beta-blocker to ease your heart’s activity and limit the injury done to heart tissue. After the heart attack, beta-blockers can help pre- vent another one from occurring. You may take the drugs inde?nitely to reduce your risk of another heart attack.
Although beta-blockers are a well-established remedy for heart con- ditions, some people who take them experience muscle fatigue after exercise, light-headedness, or fainting. If you have a lung condition such as asthma, beta-blockers can cause a spasm of the bronchial muscles and thus interfere with passage of air into the lungs, resulting in shortness of breath or wheezing. Some people with diabetes may have light- headedness if the drug interferes with their recognition of when their blood sugar levels are too low. If you experience any side effects from beta-blockers, notify your doctor immediately. A different beta-blocker or an adjustment in the dosage may resolve the problem. However, do not stop taking the drug suddenly, and try not to miss any doses because that could worsen any cardiac symptoms. If you are taking other medi- cines or herbal remedies, be sure to tell your doctor to avoid a harmful drug interaction.
The following are some commonly prescribed beta-blockers, listed by their generic names: acebutolol, atenolol, betaxolol, bisoprolol, carvedilol, metoprolol, nadolol, pindolol, propranolol, sotalol, and timolol.

Calcium Channel Blockers

A group of drugs called calcium channel blockers, or calcium antagonists, relax the arteries and increase the supply of blood to the heart, while reducing its workload by decreasing blood pressure, heart rate, and muscular contraction. Chemically, calcium channel blockers work by preventing an essential step in the process of muscle contraction the movement of calcium into muscle cells in the heart and blood vessels. As a result, the heart and blood vessels relax. Calcium channel blockers may be prescribed for high blood pressure  or angina and may also be used to prevent migraine headaches. Calcium channel blockers are also very effective for the treatment of coronary spasm and the variant angina it causes.
There are many calcium channel blockers, including both short-acting and longer-acting types. Calcium channel blockers are often used in com- bination with beta-blockers. Possible side effects vary with different types of the drug, but some people experience headache; tenderness, swelling, or bleeding of the gums; drowsiness; constipation; or a slow pulse rate (less than 50 beats per minute). Talk to your doctor immediately about any side effects, but do not stop taking the medication abruptly.
The following are some frequently prescribed calcium channel blockers, listed by their generic names: amlodipine, bipridil, diltiazem, felodipine, isradipine, nicardipine, nifedipine, nisoldipine, and verapamil.

ACE Inhibitors

ACE (angiotensin-converting enzyme) inhibitors are a group of drugs widely prescribed to treat high blood pressure and are now also given to many people after a heart attack to improve heart function. After a heart attack, some heart muscle is damaged and weakened, and it may con- tinue to weaken over time. By lessening the workload of the heart and arteries, ACE inhibitors slow down this weakening.
As antihypertensives (drugs that lower blood pressure), ACE inhibitors reduce the workload on the heart caused by hypertension, and help prevent damage to the blood vessels of the heart, brain, and kidneys. Controlling high blood pressure reduces the likelihood of stroke, heart failure, kidney failure, and heart attack.
ACE inhibitors appear to work by blocking an enzyme (protein) in the body that helps produce angiotensin, a substance that makes the blood vessels contract. By inhibiting this process, the drugs relax blood vessels, the vessels expand, blood pressure goes down, and the workload for the heart decreases.
If your doctor prescribes ACE inhibitors after a heart attack, you will probably take the drugs for the rest of your life. These drugs also control blood pressure and preserve kidney function in people with diabetes.

ACE inhibitors tend to increase the level of potassium in your blood, so it is particularly important that you remind your doctor if you are taking potassium, salt substitutes (which often contain potassium), or low-salt milk (which can increase potassium levels). Talk to your doctor about any other medications you are taking, and check with him or her before using any over-the-counter medications or supplements.
Some people taking ACE inhibitors experience side effects including dizziness, light-headedness, or fainting; skin rash; fever; or joint pain. If you experience any of these effects or others, check with your doctor as soon as possible. A high potassium level often has no symptoms or very nonspeci?c symptoms such as nausea, weakness, malaise (feeling list- less), palpitations, irregular heartbeat, or a slow or weak pulse. Tell your doctor if you experience these symptoms. However, high potassium levels usually cause few symptoms until they are dangerously high, so your doctor may periodically monitor the potassium level in your bloodstream.
The following are commonly prescribed ACE inhibitors, listed by their generic names: benazepril, captopril, enalapril, enalaprilat, fosino- pril, lisinopril, perindopril, quinopril, ramipril, and trandolapril.
Angiotensin-2 receptor blockers (ARBs) may be prescribed. ARBs differ from ACE inhibitors in that ARBs inhibit the effect of angio- tensin, rather than blocking it in the ?rst place .