In addition to lifestyle changes, many people with high blood pressure must take at least one medication or a combination of drugs to keep their blood pressure at a healthy level. These drugs, called antihyper- tensives, are highly effective and are an extremely important factor in reducing your risk of stroke, heart disease, and other major diseases related to high blood pressure. Many different types of drugs and combinations of drugs have been developed, so you and your doctor can work together to ?nd the ones that will successfully control your blood pressure with the fewest possible side effects. Although antihyperten- sives are powerful drugs, they have fewer unpleasant side effects today than ever before.
If you have not been taking medications until now, and especially if you feel ?ne, you may not look forward to the idea of taking drugs that may have side effects and may be expensive. It could take some time to tailor your drug regimen to your needs, but do not get discouraged. Tell your doctor as much as you can about how the drugs make you feel. If

you experience side effects, your doctor will probably substitute another medication that does not have the same effect on your body. Some peo- ple are able to reduce their need for medication if they can bring their blood pressure down and maintain it for a year or more, particularly if they lose weight as needed and adopt a healthier lifestyle generally. But you usually cannot stop treatment altogether. If the cost of your drugs is a problem, talk to your doctor about that, too. There may be lower- priced alternatives.
Once you start taking prescription medications, do not stop or change your regimen without talking to your doctor ?rst. Even if the medicine is working and your blood pressure goes down, you need to continue taking the drug in order to get the bene?t. If you hear about a new drug or you talk to someone who is taking something different from what you are taking, talk it over with your doctor. Everyone responds differently to these medications and has a different medical history, so not every drug will be right for you. The most important goal is to get your blood pressure to a healthy level and keep it there for the rest of your life. Make sure to take your medication every day, even if you feel ?ne; if you have forgotten a dose, look at the patient informa- tion sheet that comes with your prescription to determine if you should take a “catch-up” dose or if it is preferable to wait till the next dose is due.
There are eight major categories of antihypertensive medications, each with a different mechanism of action in your body. Within these eight categories, individual drugs have generic names and a brand name registered to a particular pharmaceutical company. Whatever the cate- gory of medication, taking medication may lead to a decrease of up to
10 percent in your systolic blood pressure and 5 percent in your dias- tolic blood pressure. Many of these drugs are also prescribed for heart disease, so you can find more information about them on pages
165–173 and 241–246. Here is a summary of the broad categories and their method of action:
• Diuretics rid your body of excess ?uids and sodium through uri- nation, lessening the volume of blood that your heart has to pump. Your treatment will almost certainly begin with a diuretic, alone or in combination with another medication. Diuretics are some- times also used to enhance the blood-pressure-lowering effects of other drugs. Common examples include amiloride, bumetanide, chlorothiazide, chlorthalidone, hydrochlorothiazide, indapamide, metalozone, and spironolactone. The adverse effects of diuretics may include urinary frequency and low potassium levels.• Angiotensin-converting enzyme (ACE) inhibitors lower the levels of angiotensin, a chemical in your body that constricts your blood vessels, so your vessels expand, reducing resistance to blood ?ow, and allowing your heart to pump more ef?ciently. Examples include benazepril, captopril, enalapril maleate, and lisinopril. ACE inhibitors should not be used in pregnancy. They have a low incidence of side effects compared to other medications for high blood pressure. The most common side effect is a cough, which develops in 5 to 15 percent of cases. Rarely, people will have swelling in the face, a potentially dangerous side effect that means you should discontinue the drug immediately. However, talk to your doctor promptly to report your reaction and get another prescription.

• Angiotensin-2 receptor blockers inhibit the effect of angiotensin (rather than lowering the level), so they too prevent angiotensin’s effects on your heart and vessels. They are often pre- scribed for people who cannot take ACE inhibitors. Examples include losartan, candesartan, and valsartan. Side effects may include nausea or a headache.

• Alpha-blockers prevent your arteries from constricting and block the effects of the stress hormone epinephrine, which elevates blood pressure. These drugs are no longer highly recommended but are prescribed occasionally. Examples include doxazosin, prazosin, and terazosin. The major side effect is dizziness.

• Beta-blockers (see illustration on page 62) decrease your heart rate and cardiac output, which lowers your blood pressure. Exam- ples include atenolol, metoprolol, and propranolol. Beta-blockers are commonly used to treat angina and are good choices for peo- ple with coronary artery disease and hypertension. Fatigue is a common side effect.

• Calcium channel blockers inhibit the movement of calcium into your heart and blood vessels, which relaxes the muscles in the arterial wall that constrict the artery, preventing the narrowing of the artery. Examples include diltiazem, amlodipine, and vera- pamil. Side effects include leg swelling and constipation.

Beta-blocker action
7Beta-blocker drugs, often prescribed for hypertension, work by blocking the effects of epinephrine and norepi- nephrine—hormones that stimulate heart muscle cells and cause a more rapid heart rate. The drugs occupy receptor sites on the muscle cells to interfere with the hormones, preventing the increase in heart rate and low- ering the force of heart contractions. Both the heart rate and the strength of the contractions are controlled by neurons that carry nerve signals from the brain to the heart (see figure at right).

• Centrally acting drugs (or central alpha agonists) act on the brain and the nervous system to lower your heart rate and prevent the arteries from narrowing but are rarely used now. Examples include clonidine, guanfacine, and methyldopa. Clonidine is unique in that in addition to being available in oral form, it is available in a skin patch, which is applied once a week. Side effects of centrally acting drugs include sedation, dizziness, dry mouth, and fatigue.

• Vasodilators cause the muscular walls of the blood vessels to relax so that the vessels can dilate (widen). These drugs are used only in emergencies or for people whose blood pressure cannot be con- trolled with other drugs. Examples are hydralazine and minoxidil. Minoxidil may cause you to retain ?uids, so it should be used in combination with diuretics, which will help remove ?uid from your system.

The more familiar you are with your drug program, the easier it will be to talk to your doctor about it and take the medications correctly so that they work as they should. Here are some important points to know about your high blood pressure medication or that of a family member whom you are assisting:
• The name of the medication
• What it does in your body
• How often to take it and how much to take
• What time of day to take it
• What food, drink, or other medications you should avoid while taking it
• How to store it (is it sensitive to heat or dampness?)
• What reactions or side effects might occur and what to do if you get them
• What to do if you miss a dose
• Speci?c side effects if you are a woman and you become pregnant
• When you need to re?ll your prescrip- tion so you do not run out.

WARNING!

Cold and Flu Medications
Most over-the-counter cold and flu prod- ucts contain decongestants that can raise your blood pressure or interfere with your blood pressure medication. If you are on blood pressure medication, consult your doctor before you use any over-the-counter remedies. If your blood pressure is well con- trolled, your doctor may allow you to take cold and flu products for a few days. How- ever, decongestant-free products are avail- able that are safe and effective for coughs, colds, or flus. Always read the label carefully on any over-the-counter drug to be sure it does not contain any ingredients that raise your blood pressure or interfere with your treatment. In addition, if you are taking the over-the-counter medications ibuprofen or naproxen sodium for another problem such as arthritis pain, be sure to tell your doctor; these drugs can raise your blood pressure.