DRUG THERAPY FOR HIGH BLOOD PRESSURE
Posted: under Cardio & Blood- Сholesterol.
From their research into the body’s own blood-pressure control mechanisms, scientists have developed several classes of drugs:• Diuretics (water pills). These chemicals stimulate the kidneys to remove water and salt from the blood system, reducing blood pressure.• Beta-blockers. These medicines block the action of epinephrine (also known as adrenaline) and norepinephrine, thereby decreasing the heartbeat rate and the vigor of each contraction.• Calcium channel blockers. They prevent calcium from entering the tiny artery muscles and causing them to constrict, which raises blood pressure.• ACE inhibitors. ACE stands for angiotensin converting enzyme. Angiotensin II, a hormone originating in the kidneys, raises blood pressure by constricting the artery muscles. The new drugs inhibit or halt production of angiotensin II. Without angiotensin II, the arteries relax and blood pressure drops.• Vasodilators. These drugs work directly on the artery muscles, relaxing them.• Central agents. These chemicals work primarily in the lower part of the brain, where they prevent nerves from sending out signals to release the hormones that, in turn, raise blood pressure.Several studies, involving more than 10,000 patients, clearly show that these drugs not only lower pressure but also reduce the incidence of strokes and other cardiovascular problems, thereby lowering death rates.Tests of the newest classes of drugs – calcium channel blockers and ACE inhibitors – show that they do lower blood pressure, but proof that they save lives is lacking. Doctors are increasingly prescribing them because they have fewer side effects than the old medications. The chief drawback is that they are expensive.Katherine Echols of Atlanta discovered that her blood pressure was 162/113, placing her at risk of a stroke or heart attack. Doctors prescribed diuretics, which reduced the pressure. She also lost weight, cut her salt intake, and began a walking program for exercise. Her pressure came down. Then she tried one of the new drugs, and her last reading stood at 119/85 – definitely within the healthy range.”Once you get high blood pressure, it’s a lifetime thing,” says Ms. Echols, “It’s not a cure, but you can be helped.”*4/266/5*