http://www.nytimes.com/2002/12/18/health/18PRES.html
Older Way to Treat Hypertension Found Best By LAWRENCE K. ALTMAN Traditional water pills, or diuretics, are superior to newer, more expensive drugs in lowering high blood pressure and preventing its serious and often fatal complications, researchers said yesterday in reporting the largest study ever of the condition. Diuretics were once the mainstay of therapy to lower blood pressure, which affects about one in four adults. But their use has plummeted in recent years as manufacturers heavily promoted newer, costlier drugs, although the benefits of the new ones were rarely compared directly to diuretics or to each other. The new federally sponsored study had been long awaited because it was designed to compare the benefits of four types of drugs on major complications of high blood pressure in a large number of participants, more than 42,000, representing men and women, minority groups and people with coexistent diseases. High blood pressure, also known as hypertension, is the main factor underlying heart failure and stroke, and can lead to heart attacks. The new study found that a diuretic, chlorthalidone, was more effective in preventing fatal and nonfatal heart attacks than were three other classes of drugs: amlodipine (sold as Norvasc), a calcium channel blocker; lisinopril (Zestril and Prinivil), an ACE inhibitor; and doxazonsin (Cardura), an alpha-adrenergic blocker. The market for blood pressure lowering drugs is huge. High blood pressure affects 50 million Americans, and 24 million of them spend $15.5 billion a year for blood pressure lowering drugs. The remainder do not know they have hypertension or do not take drugs for it. The prevalence of hypertension increases with age; more than half of those over 60 have hypertension. The findings, to be reported today in The Journal of the American Medical Association, were consistent for all the groups in the study, so they should apply to nearly all people with high blood pressure, the study's leaders said at a news conference yesterday at the National Heart Lung and Blood Institute. That federal agency, in Bethesda, Md., paid $85 million for the study, which it ran independently. Pfizer, which makes Norvasc, paid an additional $40 million. Diuretics for hypertension cost about $25 a year compared with about $250 for an ACE inhibitor and $500 for a calcium channel blocker, according to Dr. Paul Whelton, a leader of the study who is also professor of epidemiology at Tulane University. "There were tremendous efforts to prevent doctors from using diuretics," Dr. Marvin Moser of Yale, an expert in hypertension, said in an interview. He said that the new findings vindicated experts who recommended the use of diuretics in the face of vast promotional efforts by some experts and manufacturers to sell more expensive patented drugs. Dr. Claude J. Lenfant, the director of the National Heart Lung and Blood Institute, said he was appointing a committee of experts to develop new national clinical guidelines for high blood pressure. Wider use of diuretics would save patients and health care insurers more than $1 billion a year, the leaders of the study said. Diuretics, which increase the flow of urine, should almost always be used first when drug therapy is needed to lower high blood pressure, said Dr. Whelton. He also said that doctors should consider switching to diuretics or adding them to existing regimens. For patients who "need more than one medication to control blood pressure � and many people do � one should be a diuretic," said Dr. Welton, who also is senior vice president for health sciences at Tulane. Dr. Jackson T. Wright Jr., a vice chairman of the study who directs the high blood pressure program at Case Western Reserve University in Cleveland, said that diuretics "are unsurpassed at lowering blood pressure and reducing clinical complications of hypertension." Health officials cautioned patients not to stop taking their blood pressure lowering drugs before consulting their physician. The findings "give policymakers, health care insurers, and those who develop treatment guidelines the green light to recommend the most effective, lowest-cost option for starting hypertension treatment," Dr. Whelton said. Dr. Lenfant's agency undertook the study in 1994 because no one knew which of the 100 marketed antihypertensive drugs belonging to seven major drug classes was the best initial treatment for high blood pressure. The Food and Drug Administration licensed the newer drugs like ACE inhibitors and calcium channel blockers because major trials showed that they lowered blood pressure and reduced the incidence of heart disease among hypertensive patients. But because these studies compared the new drugs to dummy pills, and not to each other, their relative value with older drugs was unknown. The new study involved 42,418 patients aged 55 and older who had high blood pressure and at least one other risk factor for heart disease, like diabetes or cigarette smoking. High blood pressure is defined as a systolic pressure above 140 and a diastolic pressure above 90; blood pressure is measured in millimeters of mercury. The first number measures the force that blood exerts on the artery walls as the heart contracts to pump out the blood, the second is the measure of force as the heart relaxes to allow the blood to flow into the heart. The participants, all of whom had blood pressure measured at 140/90 or higher, were treated in a variety of settings, including 623 clinics and Veterans Affairs hospitals in the United States, Puerto Rico, the Virgin Islands and Canada. Patients agreed to let a computer decide which drugs they would take without being told their identity. Doctors monitored the participants' blood pressure and health for nearly five years on average, and found that the overwhelming majority took their drugs as directed. Compared to participants who took the diuretic, the ACE inhibitor group had, on average, about two points higher systolic blood pressure, the top number in the blood pressure reading. Blacks in the group had a systolic blood pressure four points higher. There was a 15 percent higher risk of stroke overall for the ACE inhibitor group and a 40 percent higher risk for blacks. The risk for heart failure among all groups was 19 percent higher, and the risk for hospitalization or treatment for the chest pains of angina was 11 percent higher. Further, the risk of needing a coronary bypass operation or angioplasty was 10 percent higher. Compared with participants who took the diuretic, the calcium channel blocker group had, on average, a systolic blood pressure about one point higher and a 38 percent higher risk of developing heart failure. A factor in the switch from use of diuretics to newer drugs was a Swedish study reported in The New England Journal of Medicine in 1989. It found that diuretics could cause biochemical changes that were thought to increase susceptibility to heart attacks. The new study found modest evidence of the biochemical changes. Dr. Whelton's team stopped the doxazosin part of the study in March 2000 because people who took it had a 25 percent higher rate of heart disease and a doubled rate of heart failure compared with the diuretic. Precisely how diuretics reduce high blood pressure is not known, despite their use for more than half a century. Although the new study showed the superiority of diuretics over other classes of drugs, it did not explain whether the findings were from positive effects of the diuretics or negative effects of the other classes, said Dr. Michael H. Alderman, a hypertension expert at Albert Einstein Medical School. "We simply don't know whether diuretics are doing more good, or simply less harm, than the calcium channel blockers and ACE inhibitors," Dr. Alderman said. __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com --- URG-L Aimeriez-vous obtenir une adresse de courriel @URGENCES.CA? Suivez-le lien http://www.groupegiroux.com/messagerie pour de plus amples informations.
