Many medicines are used to treat patients with cardiac disease. However, individual patients may respond differently to these medications. The effectiveness of a medication may also change with time. For this reason, doctors often prescribe different medications to control, hypertension, for example, until they find a medicine or combination of medicines that works for a given patient. Commonly used medications include: ACE inhibitors, angiotensin receptor blockers, antiarrhythmics, antihypertensives, beta-blockers, calcium-channel blockers, nitrates and statins just to name a few.
ACE (angiotensin converting enzyme) inhibitors are used to treat high blood pressure and weakened heart muscles. Angiotensin II is a substance in the blood that causes vessels to tighten and elevates blood pressure. It is formed from angiotensin I in the blood by the angiotensin converting enzyme (ACE). ACE inhibitors slow (inhibit) the activity of the enzyme, which decreases the production of angiotensin II. As a result, the blood vessels enlarge (dilate), and blood pressure is reduced. In addition, these drugs decrease sodium and water retention, which often accompanies congestive heart failure (CHF). A common side effect of ACE inhibitors is a dry cough that begins 1-2 weeks after starting the medication. If this happens the physician may change the patient's medication to an Angiotensin II Receptor Blocker (ARB)
ACE inhibitors currently available in the United States include: captopril (Capoten), benazepril (Lotensin), enalapril (Vasotec), lisinopril (Prinivil, Zestril) fosinopril (Monopril), ramipril (Altace), perindopril (Aceon), quinapril (Accupril), moexipril (Univasc), and trandolapril (Mavik).
Angiotensin II Receptor Blockers
Angiotensin II is a substance in the blood that causes vessels to tighten (constrict) and elevates blood pressure. Angiotensin receptor blockers (ARBs) block the action of angiotensin II. ARBs are used for controlling high blood pressure, treating heart failure, and preventing kidney failure in people with diabetes or high blood pressure. Their effects are similar to those of ACE inhibitors so they are often used when a patient cannot tolerate an ACE inhibitor.
Currently available ARBs include: candesartan (Atacand) eprosartan (Tevetan), irbesartan (Avapro), telmisartan (Mycardis), valsartan (Diovan), and losartan (Cozaar).
Antiarrhythmic drugs are given to help slow down, speed up or regulate heartbeat. Commonly used antiarrhythmic drugs are amiodarone (Pacerone), disopyramide (Norpace, Norpace CR), procainamide (Procan SR, Pronestyl, Pronestyl-SR), and quinidine (Cardioquin, Duraquin, Quinidex, and other brands).
Anticoagulants can help prevent an existing clot from enlarging or new clots from forming in the coronary arteries; however, they do not dissolve existing clots. They are prescribed for people at particular risk for forming clots, such as those with artificial heart valves or atrial fibrillation. (See also antiplatelet drugs.)
Commonly prescribed anticoagulants include: dalteparin (Fragmin), enoxaparin (Lovenox), heparin (various) and warfarin (Coumadin)
These are used to treat high blood pressure (hypertension). The most common types include ARB, ACE inhibitors, diuretics, beta blockers and calcium channel blockers.
Like anticoagulants, antiplatelet drugs can help prevent an existing clot from enlarging or new clots from forming in the coronary arteries, but they do not dissolve existing clots. Antiplatelets are effective in the arterial circulation, where anticoagulants have little effect. They are prescribed for people at particular risk for forming clots, such as those with new stents, artificial heart valves or atrial fibrillation.
The most common antiplatelet drugs are: cyclooxygenase inhibitors (aspirin); adenosine diphosphate receptor inhibitors, such as clopidogral (Plavix) and ticlopidine (Ticlid); phosphodiesterase inhibitors, such as cilostazol (Pletal); glycoprotein IIB/IIIA inhibitors (intravenous use only), such as abciximab (ReoPro), eptifibatide (Integrilin), and tirofiban (Aggrastat); and adenosine reuptake inhibitors, such as dipyridamole (Persantine).
Arginine vasopressin receptor antagonists
are currently in clinical trials and could serve as an adjunct to or replacement of standard diuretic therapy in selected patients. The congestive (fluid backup) symptoms experienced by heart failure patients may be due, in part, to elevated vasopressin levels. By blocking the action of vasopressin, the experimental drug has proved successful in clinical trails in lessening congestion in these patients without having deleterious effects on blood pressure, heart rate, potassium levels, or kidney function. Further studies are under way to determine if the drug actually extends survival in heart failure patients.
Aspirin is an effective therapy in reducing the occurrence of myocardial infarction (heart attack). Heart attacks occur when atherosclerotic plaque, that is already partially obstructing a coronary artery, ruptures (breaks apart). This creates a roughened surface along the lining of the vessel and promotes clotting. As a clot forms, it obstructs the vessel completely. Blood clots are formed by platelets clustering together. Aspirin interferes with this process by making the platelets less "sticky" -- and therefore less successful in clustering together.
Beta-blockers (beta-adrenergic blocking drugs) slow the heart rate and decrease blood pressure, reducing the heart's demand for oxygen. They do this by blocking the effects of adrenaline on the body's beta receptors. This slows the nerve impulses that travel through the heart, thus easing the heart's pumping action and widening blood vessels. Beta-blockers also can block the impulses causing an irregular heartbeat (arrhythmia).
Beta-blockers are used to treat a variety of conditions including high blood pressure (hypertension), chest pain (angina), arrhythmias, congestive heart failure (CHF), and mitral valve prolapse.
Commonly used beta blockers include: acebutolol (Sectral), atenolol (Tenormin), betaxolol (Kerlone), bisoprolol (Zebata), carteolol (Cartrol), carvedilol (Coreg), esmolol (Brevibloc), labetalol (Normodyne, Trandate), metoprolol (Toprol-XL, Lopressor), nadolol (Corgard), propranolol (Inderal, Inderal-LA), sotalol (Betapace), and. timolol (Blocadren).
Bile-acid sequestrants are used to reduce high cholesterol, which increases the risk of coronary artery disease. They bind to bile from the liver (which is made up mostly of cholesterol) and prevent it from being reabsorbed into the circulation so less cholesterol gets into the body. Common bile acid sequestrants include cholestyramine resin (Prevalite, Questran), colesevalam (Welchol) and colestipol (Colestid).
Calcium Channel Blocking Agents
Also called calcium antagonists or calcium blockers, these medications affect the movement of calcium into the cells of the heart and blood vessels. As a result, they relax blood vessels and increase the supply of blood and oxygen to the heart, while reducing its workload. They are prescribed to treat chest pain (angina), high blood pressure (hypertension) and some irregular heartbeats (arrhythmias).
Calcium channel blockers include: amlodipine (Norvasc), diltiazem (Cardizem), felodipine (Plendil), nicardipine (Cardene), nifedipine (Adalat, Procardia), nimodipine (Nimotop), and verapamil (Calan, Covera, Isoptin). They are not usually prescribed for people with heart failure or other structural damage to the heart.
Cholesterol is necessary for building new cells, insulating nerves and producing hormones, but sometimes the body creates and absorbs too much cholesterol, resulting in blocked arteries. Common types of cholesterol-lowering drugs include Niacin, bile-acid sequestrants and HMG-CoA reductase inhibitors (statins).
Digitalis, which is derived from the foxglove plant, is used to treat congestive heart failure (CHF) and certain abnormal heart rhythms (arrhythmias). It increases the force of the heart's contractions by increasing the amount of calcium in the heart's cells (which stimulates the heartbeat), helping to improve circulation and reduce swelling in the hands and ankles. When digitalis reaches the heart muscle, it binds to sodium and potassium receptors. These receptors control the amount of calcium in the heart muscle by stopping the calcium from leaving the cells. As calcium builds up in the cells, it causes a stronger heartbeat.
Digitalis medicines help control arrhythmias by slowing the signals that start in the sinoatrial (SA) node. This then reduces the number of signals that travel through the atrioventricular (AV) node. Fewer signals equate to fewer arrhythmias.
Commonly used brand names include: Lanoxicaps (digoxin), Lanoxin (digoxin), Lanoxin Elixir Pediatric (digoxin), Lanoxin Injection (digoxin), Lanoxin Injection Pediatric (digoxin)
Diuretics are commonly used to treat high blood pressure (hypertension), congestive heart failure (CHF), and water retention and swelling often associated with CHF. They act on the kidneys to help rid the body of excess water and sodium, which can increase blood pressure.
There are three types of diuretic medicines. Each works a little differently, but all lower the amount of salt and water in the body, which helps to reduce blood pressure:
Thiazide diuretics. These are the only type of diuretic that widens (dilates) the blood vessels, which also helps to lower blood pressure. Commonly used thiazides include: bendroflumethiazide (Naturetin), chlorothiazide (Diuril), chlorthalidone (Hygroton, Thalitone), hydrochlorothiazide (Esidrix, Hydro-chlor, Hydro-D, HydroDIURIL, Microzide, Oretic), hydroflumethiazide (Diucardin, Saluron), methyclothiazide (Aquatensen, Enduron), metolazone (Diulo, Mykrox, Zaroxolyn), polythiazide (Renese), quinethazone (Hydromox), and trichlormethiazide (Metahydrin, Naqua, Trichlorex)
Potassium-sparing diuretics. Unlike the other diuretic medicines, these do not cause the body to lose potassium. They include: amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
Loop-acting diuretics. These prompt the kidneys to increase urine flow, which helps reduce water retention and lowers blood pressure. They include: bumetanide (Bumex), ethacrynic acid (Edecrin), furosemide (Lasix, Myrosemide), and torsemide (Demadex).
Statins (HMG-CoA Reductase Inhibitors)
These are prescribed to lower cholesterol in the blood. Drugs in this class include: atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), pravastatin (Pravachol), rosurastatin (Crestor) and simivastatin (Zocor). Collectively, these are known as "the statins."
Doctors often prescribe statins if diet, weight loss, and exercise don't work to sufficiently lower a person's cholesterol. Statins work by slowing the body's ability to produce low-density lipoproteins (LDL) -- also called "bad cholesterol" -- as well decreasing blood fats called triglycerides. Statins also increase blood levels of high-density lipoproteins (HDL) -- or "good cholesterol."
Inotropes may be used for patients who are hospitalized to strengthen the heart's pumping action. They are given intravenously. There are two basic types of inotropes:
b-adrenergic agonists stimulate the body's production of norepinephrine, which stimulates the heart to work harder. These include dobutamine and dopamine.
Phosphodiesterase-III inhibitors stimulate the heart to beat more strongly and also relax the blood vessels. The most common drug of this type is milrinone (Primacor).
Niacin lowers low-density lipoproteins ("bad cholesterol") and raises high-density lipoproteins ("good cholesterol") in the blood.
Nitrates are used to treat the symptoms of angina (chest pain). They act to relax the blood vessels, thereby lowering the blood pressure, increasing blood flow and oxygen supply to the heart and decreasing its workload. Nitrates can be taken a number of ways which changes its purpose. As a rapid dissolving pill or spray under the tongue, it is absorbed rapidly and can stop the onset of symptoms or relieve symptoms of angina that are occurring. As an extended-release pill (swallowed) or cream (absorbed through the skin) it can reduce the number of angina attacks that occur.
Clot-Dissolving Drugs (Thrombolytics)
Thrombolytic, or clot-dissolving, drugs cause the breakdown of blood clots that obstruct the flow of blood through the coronary arteries. Thrombolytics are injected during or shortly after a heart attack (myocardial infarction) to dissolve the clot and help preserve as much heart tissue as possible. The longer the heart is deprived of oxygen and nutrients, the more tissue is irreparably damaged. Function cannot be restored to dead heart muscle tissue.
Thrombolytic drugs include: tPA (alteplase Activase), reteplase (Retavase), urokinase (Abbokinase), streptokinase (Kabikinase, Streptase), tenectaplase and lanoteplase. They are most effective if administered immediately after they have been determined to be clinically appropriate. The benefit is highest within the first 90 minutes, but may extend up to six hours after the onset of symptoms.
Vasodilators cause the blood vessel walls to relax or increase in width (dilate), which allows more blood to reach the heart muscle, providing it with more oxygen and nutrients and helping it work more efficiently. They may be used to treat angina (chest pain) and control high blood pressure (hypertension).
Examples of vasodilators are hydralazine (Apresoline, Alazine), minoxidil (Loniten), ACE inhibitors, angiotensin II receptor blockers, beta blockers, calcium channel blockers, natriuretic peptides and nitrates.