New Drug Better at Handling Pressure
An estimated 50 million Americans have high blood pressure, a major risk factor for heart attacks and stroke, but only about half are being treated for the condition, and only one in four has it under control. But a new family of drugs led by a chemical called omapatrilat may sharply improve doctors’ success in treating the “silent killer”--and also cut sharply into the market share of the leading antihypertensive drug Norvasc.
New results with omapatrilat, trade named Vanlev, were presented last week at the American Heart Assn.’s annual meeting in Atlanta. Other presentations brought encouraging news about cholesterol, a new warning about the dangers of obesity and troubling hints about potential side effects of AIDS therapy.
High blood pressure is defined as a systolic blood pressure of 140 millimeters of mercury (mm Hg) or higher and a diastolic pressure of 90 mm Hg or higher. Drugs like Norvasc, which has annual sales of $3 billion a year, bring both numbers down but produce their greatest effects on diastolic pressure. Recent research, however, has shown that the risks of heart attacks, strokes and kidney failure are more closely associated with high systolic pressures.
Vanlev is a member of a new family of drugs called vasopeptidase inhibitors. Like ACE (angiotensin converting enzyme) inhibitors such as Norvasc, they block the action of angiotensin, a naturally occurring chemical that raises blood pressure by causing blood vessels to constrict. But it also blocks a substance called neutral endopeptidase, which causes constriction by a different mechanism.
Dr. Michael A. Weber of Brookdale University Hospital and Medical Center in Brooklyn reported on a study in which 213 patients in their early to mid-50s were given Vanlev and 217 were given Norvasc. Among those receiving Vanlev, systolic pressure was reduced by 20 mm Hg and diastolic pressure by 13 mm Hg, while the corresponding numbers for Norvasc were 15 mm Hg and 10 mm Hg.
A separate study in older patients showed a similar benefit for Vanlev, Weber said.
Vanlev may also be useful in treating congestive heart failure (CHF), a condition in which the heart is weakened and can’t pump enough blood to meet the needs of other organs in the body. CHF is also treated with ACE inhibitors, but vasopeptidase inhibitors may be superior, according to Dr. Jean-Lucien Rouleau of the University Health Network of Toronto.
Rouleau studied 289 CHF patients who received Vanlev and 284 who received the ACE inhibitor lisinopril. Their average age was 64, and 79% were male.
After 12 weeks of therapy, Rouleau told meeting participants, both groups had significantly better performance on treadmill tests, a measure of heart function. But only 16 in the Vanlev group died or underwent hospitalization for worsening heart failure, compared with 29 in the lisinopril group.
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Fresh orange juice can have a significant effect on cholesterol levels, according to another Canadian study. The study is particularly important, according to lead researcher Dr. Elzbieta Kurowska of the University of Western Ontario, because it is normally difficult to change cholesterol levels through diet.
Kurowska studied 25 men and women with moderately high cholesterol levels who consumed three 8-ounce glasses of fresh orange juice per day. After four weeks, their levels of high-density lipoprotein (HDL, the so-called good cholesterol) had increased by 21%, while the ratio of HDL to low-density lipoprotein (so-called bad cholesterol) fell by 16%. The juice also increased the subjects’ levels of Vitamin C and folate, which is thought to play a beneficial role in protecting against heart disease.
In other studies:
* Researchers from Duke University Medical Center found that overweight people develop heart disease an average of three years earlier compared with those of normal weight (61 versus 64), while the most obese develop it six years earlier. Normal-weight patients had a life expectancy of 78 years, compared with 77 for overweight patients and 74 for the most obese.
* Patients who take “cocktails” of drugs for HIV infection may stave off AIDS, but they may be increasing their risk of heart disease, according to Dr. James Sosman of the University of Virginia. Sosman studied the interiors of blood vessels in subjects taking the cocktails and found that they showed early signs of atherosclerosis. Such patients may have to take cholesterol-lowering drugs, he said.
* Cocaine use sharply increases the risk of aneurysms, a potentially fatal ballooning-out of the wall of the artery, according to Dr. Aaron Satran of the Hennepin County Medical Center in Minneapolis. Satran studied 112 young people who used cocaine and had heart pains and found that 30% had an aneurysm in a heart artery. Among non-drug users referred for angiography because of heart pains, about 5% had similar aneurysms.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
