Medications:

Several classes of drugs are used to treat hypertension.

Diuretics

Diuretics help the kidneys get rid of excess salt and water. They are the mainstays of anti-hypertensive therapy and are often the first drug selected for most people with hypertension. They are also especially helpful for treating patients with heart failure, patients with isolated systolic hypertension, the elderly, and African-Americans. (African-Americans are more likely to be salt-sensitive, so they respond well to these drugs.) They also work well for patients with diabetes. Diuretics are often used in combination with other antihypertensive drugs.

Results of a major long-term study have suggested that diuretics work just as well as newer drugs in lowering blood pressure and are more effective in preventing heart failure, heart attack, and stroke.

Diuretic Types and Brands. The three main types of diuretics include:

• Thiazide diuretics. These include chlorothiazide (Diuril), chlorthalidone (Hygroton), indapamide (Lozol), hydrochlorothiazide (Esidrix, HydroDiuril), bendroflumethiazide (Naturen), methylclothiazide, (Edduran), and metolazone (Mykrox, Zaroxolyn). In most cases, thiazides are preferred to other diruetics for treatment of high blood pressure.
• Potassium-sparing diuretics. These include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
• Loop diuretics. Because loop diuretics act faster than other diuretics it is important to avoid dehydration and potassium loss. Loop diuretics include bumetanide (Bumex), furosemide (Lasix), ethacrynic acid (Edecrin), and torsemide (Demadex).

Problems with Diuretics.

• Loop and thiazide diuretics reduce the body's supply of potassium, which, if left untreated, increases the risk for arrhythmias. Arrhythmias are heart rhythm disturbances that can, rarely, lead to cardiac arrest. In these cases, doctors will prescribe lower doses of the current diuretic, recommend potassium supplements, or use potassium-sparing diuretics either alone or in combination with a thiazide.
• Potassium-sparing drugs have their own risks, which include dangerously high levels of potassium in people with existing elevated levels of potassium or in those with damaged kidneys. However, all diuretics are generally more beneficial than harmful.
• Thiazide diuretics may increase blood sugar levels.
• Erectile dysfunction (impotence) may be a side effect of thiazides.
• Elevated uric acid levels, and possibly gout, may be caused by thiazide diuretics.

Common Diuretic Side Effect Symptoms.

• Fatigue
• Depression and irritability
• Urinary incontinence
• Reduced sexual drive and problems with obtaining and maintaining an erection

Beta Blockers

Beta blockers help slow heart rate and lower blood pressure. They are usually used in combination with other drugs such as ACE inhibitors and diuretics. Beta blockers are more likely to be used to treat hypertension in patients with angina, previous heart attack, arrhythmias with fast heart rates, or migraine headaches. With careful use, they can be beneficial for patients with heart failure.

Brands. Propranolol Propranolol (Inderal), acebutolol (Sectral), atenolol (Tenormin), betaxolol (Kerlone), carteolol (Cartrol), metoprolol (Lopressor), nadolol (Corgard), penbutolol (Levatol), pindolol (Visken), carvedilol (Coreg), timolol (Blocadren), and nebivolol (Bystolic). The drugs may differ in their effects and benefits.

Problems with Beta Blockers.

• Do not abruptly stop taking these drugs. The sudden withdrawal of beta blockers can rapidly increase heart rate and blood pressure and potentially cause angina or heart attack. If you need to stop your beta blocker, the doctor may want you to slowly decrease the dose before stopping completely.
• Beta blockers are categorized as non-selective or selective. Non-selective beta blockers, such as carvedilol and propranolol, may sometimes narrow bronchial airways. Patients with asthma, emphysema, or chronic bronchitis should not use these medicines.
• These drugs can hide warning signs of low blood sugar (hypoglycemia) in patients with diabetes. When combined with a diuretic, the risk of diabetes may increase.
• They may be less effective than other drugs for preventing stroke.

Common Side Effects.

• Fatigue and lethargy
• Vivid dreams and nightmares
• Depression
• Memory loss
• Dizziness and lightheadedness
• Reduced ability to exercise
• Coldness in extremities (legs, toes, arms, hands)
• Reduced sexual drive and problems with obtaining and maintaining an erection

Check with your doctor about any side effects. Do not stop taking these drugs on your own.

ACE Inhibitors

Angiotensin-converting enzyme (ACE) inhibitors widen blood vessels and decrease the workload of the heart. They treat high blood pressure and can also help protect the heart and kidneys.

Patients with heart failure or an enlarged left ventricle, previous heart attack, diabetes, or kidney disease are considered particularly good candidates for ACE inhibitors as part of treatment for high blood pressure.

Aspirin is recommended for preventing death in patients with heart disease, and can safely be used in combination with ACE inhibitors, particularly at lower dosages of aspirin (75 - 81 mg).

Brands. ACE inhibitors include captopril (Capoten), enalapril (Vasotec), quinapril (Accupril), benazepril (Lotensin), ramipril (Altace), perindopril (Aceon), and lisinopril (Prinivil, Zestril).

Common Side Effects of ACE Inhibitors.

• Low blood pressure is the main side effect of ACE inhibitors. This can be severe in some patients, especially at the start of therapy.
• Irritating cough is a common side effect, which some people find intolerable.
• ACE inhibitors can harm a developing fetus and should not be used during pregnancy. Women who become pregnant should change from ACE inhibitors to another type of blood pressure drug as soon as possible. Women of child-bearing age who are considering becoming pregnant should also discuss other medications with their doctors.
• ACE inhibitors can increase potassium levels, particularly in patients with kidney disease.

Uncommon Side Effects of ACE Inhibitors.

• ACE inhibitors protect against kidney disease, but they may also increase potassium retention by the kidneys. If potassium levels become extremely high, they can cause the heart to stop beating (cardiac arrest). This side effect is uncommon, except in patients with significant kidney disease. Because of this risk, ACE inhibitors are not usually used in combination with potassium-sparing diuretics or potassium supplements.
• A rare but severe side effect is granulocytopenia, an extreme reduction in infection-fighting white blood cells.
• In very rare cases, patients suffer a sudden and severe allergic reaction, called angioedema that causes swelling in the eyes and mouth and may close off the throat.

Patients who have difficulty tolerating ACE inhibitor side effects are usually switched to an angiotensin-receptor blocker (ARB).

Angiotensin-Receptor Blockers (ARBs)

ARBs, also known as angiotensin II receptor antagonists, are similar to ACE inhibitors in their ability to widen blood vessels and lower blood pressure. They may have fewer or less-severe side effects than ACE inhibitors, especially coughing, and are sometimes prescribed as an alternative to ACE inhibitors. In general they are prescribed to patients who cannot tolerate or did not respond to ACE inhibitors.

Brands. Losartan (Cozaar, Hyzaar), olmesartan (Benicar) candesartan (Atacand), telmisartan (Micardis), eprosartan (Teveten), irbesartan (Avapro), and valsartan (Diovan). A combination medication containing candesartan and the diuretic hydrochlorothiazide (Diovan HCT, Atacand HCT) is also available.

Side Effects.

• Low blood pressure
• Dizziness and lightheadedness
• Raised potassium levels
• Drowsiness
• Nasal congestion
• Should not be used during pregnancy

Calcium-Channel Blockers (CCBs)

Calcium-channel blockers (CCBs), or calcium antagonists, help relax blood vessels. Along with diuretics, CCBs may work better than other drug classes for lowering blood pressure in African-Americans. Recent research indicates that newer types of drugs (CCBs, ACE inhibitors) may be a better treatment option for some patients than older drugs (especially beta blockers).

Brands. Diltiazem (Cardizem, Dilacor), amlodipine (Norvasc), felodipine (Plendil), isradipine (DynaCirc), verapamil (Calan, Isoptin, Verelan), nisoldipine (Sular), nicardipine (Cardene), nifedipine (Adalat, Procardia), lercanidipine (Zanidip), lacidipine (Motens), and nitrendipine (Nitrepin). For patients who have both high blood pressure and high cholesterol, Caduet combines in one pill amlodipine and the statin drug atorvastatin.

Side Effects.

• Swelling in the feet
• Constipation
• Fatigue
• Erectile dysfunction
• Gingivitis
• Rash
• Food interactions (do not take CCBs with grapefruit or Seville orange products)

Alpha Blockers

Alpha blockers such as doxazosin (Cardura), prazosin (Minipress), and terazosin (Hytrin) help widen small blood vessels. They are generally not used as first-line drugs for high blood pressure, but are prescribed if other drugs do not work or as add-on medication.

Vasodilators

Vasodilators help open blood vessels by relaxing muscles in the blood vessel walls. These drugs are usually used in combination with a diuretic or a beta blocker. They are rarely used by themselves. Vasodilators include hydralazine (Apresoline), clonidine (Catapres), and Minoxidil (Loniten). Some of these drugs should be used with caution or not at all in people who have angina or who have had a heart attack.

Other Drugs

Aliskiren (Tekturna). In 2007, the FDA approved aliskiren for treatment of high blood pressure. Aliskiren can be taken either alone or in combination with other blood pressure medication. It should not be used during pregnancy as it can cause injury or death to the fetus. Aliskiren inhibits renin, a kidney enzyme associated with the regulation of blood pressure.