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The thiazide class of diuretics (water pills) are the drugs of choice for most people in treatment of high blood pressure. This is the research finding of the landmark study known as ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial). Diuretics are drugs that remove excess water and sodium from the body through increased urine excretion. As a result, the volume of fluid decreases in the bloodstream and pressure declines in the arteries. Both these effects lead to lowering of blood pressure. Here are the key findings of ALLHAT regarding blood pressurelowering therapy:

• If medication is needed to treat high blood pressure, begin the treatment with a diuretic. The diuretics should be the drugs of choice for most people.

• Diuretics of the thiazide class are superior in preventing heart attack and stroke. This class of drugs has been shown to achieve better control of blood pressure than other drugs. Hydrochlorothiazide, also known as HCTZ, is at present the most popular drug in the thiazide class.

• If you take more than one drug to treat high blood pressure, but the blood pressure is still high, ask the doctor if you can add a diuretic.

• While using two or more drugs to treat high blood pressure, a diuretic should be a part of the combination.

• Because the diuretics generally have a protective effect on the heart, talk to your doctor to switch over to the thiazide type of medication, even if a different type of drug is well controlling your blood pressure.

• People with high blood pressure who cannot take diuretics (such as people in whom these drugs promote insulin resistance and raise blood sugar) can be treated with other blood pressure-lowering drugs such as ACE inhibitors (examples: ramipril, enalapril) and calcium channel blockers (see below). Calcium Channel Blockers Calcium channel blockers (CCBs), also called calcium antagonists, are drugs that slow the rate at which the calcium particles pass into the heart muscle and into the walls of the blood vessels. This action relaxes the blood vessels, thereby allowing the blood to flow more easily. Increased blood flow into the coronary arteries leads to lowering of blood pressure and lessening of angina.

CCBs do not raise blood sugar, and may be a good substitute for people who cannot use diuretics because of their unfavorable effect on blood sugar. Also, considering the recent safety concerns raised about the use of beta-blockers as blood pressure-lowering drugs (see below), CCBs can be a safer choice in treatment of high blood pressure and angina, as well.

Calcium channel blockers are of two kinds: long-acting and short-acting. Long-acting CCBs, taken once daily, are considered to be safe and are therefore preferred. However, short-acting drugs of this class such as nifedipine (Procardia, Adalat), which are taken three or four times a day are avoided for safety reasons. These drugs, some reports suggest may Drugs of Choice for High Blood Pressure 51 increase the risk of death from heart attack, especially in people with diabetes. The side effects of CCBs may include rapid heart rate, flushing, and swelling of the ankles.

CCB drugs include amlodipine (Norvasc), felodipine (Plendil), nifedipine long-acting (Adalat CC), isradipine (Dynacirc CR), diltiazem (Cardizem), and verapamil (Calan SR, Verelan).

BETA-BLOCKERS
Beta -blockers are recognized as the first line drugs in the treatment of high blood pressure and are effectively used in avoiding the symptoms of angina. These drugs achieve these results by reducing the force and rate of heart contraction, which, in turn, lessen the workload on the heart and its need for oxygen. Betablockers in small doses are known to cut the risk of heart attack, a benefit that helps increase the life span of people with heart disease. In addition, these drugs help prevent heartbeat irregularities (arrhythmia) by blocking the disturbance-producing impulses in the body.

Beta-blockers include metoprolol (Lopressor), metoprolol extended release (Toprol XL), atenolol (Tenormin), betaxalol (Kerlone), nadolol (Corgard), and propranolol (Inderal).

Caution: Although beta-blockers are known for their beneficial effect in heart disease, a study published in the medical journal Lancet in November 2005 has questioned the safety of all kinds of beta-blockers in the treatment of primary hypertension. Primary hypertension is the most common form of high blood pressure, which has no known cause, and accounts for about 90 to 95 percent of all cases of high blood pressure. (Secondary hypertension, on the other hand, has a known cause such as kidney disease.) The above noted study reports that the treatment of high blood pressure with beta-blockers is associated with an increased risk for strokes. Researchers of the study strongly suggest that beta-blockers should not remain the first choice in the treatment of primary high blood pressure. Another study published in the same journal in November 2004 had reported that the treatment of high blood pressure with atenolol, a kind of beta-blocker, increased not only the events of strokes, but also the incidence of heart attacks.