New Hope
For Those With High Blood Pressure
Novel drugs and devices
promise to improve hypertension management
By Karen Pallarito
HealthDay Reporter
SATURDAY, July 23 (HealthDay News) -- More than two-thirds of the 65
million Americans with high blood pressure require two or more
anti-hypertensive drugs to manage their condition. Many of these people also
take medicines for high cholesterol and diabetes.
That makes for a heaping mound of pills to swallow every day.
"Anybody can take a few drugs for a few months, but these people have to
be on drugs indefinitely," said Dr. John D. Bisognano, an associate
professor of medicine and director of cardiac rehabilitation and clinical
preventive cardiology at the University of Rochester Medical Center in
Rochester, N.Y.
But there is encouraging news on the horizon for people with high blood
pressure. Easier-to-take medications and novel drugs and devices promise to
improve long-term hypertension management. Basic research continues to sort
out the causes of hypertension. And vigorous prevention initiatives aimed at
sparing children from this chronic health problem breed hope for future
generations of Americans.
Hypertension, often called "the silent killer," usually occurs without
symptoms but remains a leading risk factor for stroke, heart attack, heart
failure and kidney disease. The only way to find out if you have it is to
have a blood pressure reading.
High blood pressure is literally the force exerted as blood pumps into
the arteries through the circulatory system and as the arteries resist the
flow of blood, says the American Heart Association. Systolic pressure, the
"upper" number in a blood pressure test, measures the force when your heart
is beating; the "lower" diastolic number reflects the pressure when the
heart is resting between beats.
A normal blood pressure for adults is less than 120 mmHg over less than
80 mmHg, and a reading of 140/90 mmHg or higher is considered high,
requiring medical intervention.
In 2003, the Joint National Committee on Prevention, Detection,
Evaluation, and Treatment of High Blood Pressure, a panel convened by the
federal government, added a new blood pressure category, called "prehypertension"
-- to put people on warning about the potential risk they face.
Prehypertension is defined as a pressure of 120-139/80-89 mmHg.
For people with diabetes or kidney disease, the goal is to reduce blood
pressure to 130/80 mmHg.
"One of the problems you run into is people who are at the highest risk
-- the people with diabetes and kidney disease -- often require lots of
medications to get their blood pressure down, because every medication gives
you about a 10- to 15-point drop or so," Bisognano said.
"If you're starting at 200 and need to go to 130, that's a lot of
medications," he added.
No single medication has proved to be the magic bullet for lowering blood
pressure, so doctors typically rely on a number of different
pharmaceuticals, including diuretics, angiotensin receptor blockers,
angiotensin converting enzyme inhibitors, beta blockers and calcium
channel blockers.
Pharmaceutical developers are responding to the need to make it easier
for hypertensive patients to comply with medication regimens by
developing new combination products. In the future, we will see more
fixed-dose combos of antihypertensive medications as well as pills that can
treat more than one risk factor at a time, predicts LeadDiscovery, a United
Kingdom-based research outfit.
Pfizer Inc. was the first to offer such a two-in-one product. In 2004,
the company received approval from the U.S. Food and Drug Administration to
begin marketing Caduet, a pill that contains both Norvasc for lowering high
blood pressure and Lipitor for treating high cholesterol.
There are a few new agents in the pipeline that hold promise. One novel
class of medications, called oral Renin inhibitors, works by
targeting an enzyme released by the kidneys that can affect blood pressure.
The first of these agents to be introduced on the market is likely to be
Aliskiren, a Novartis drug currently in phase III testing. Analysts
expect the company to seek regulatory approval in 2006 and are forecasting
blockbuster sales topping $1 billion by 2008 and reaching $3.6 billion by
2012, LeadDiscovery reports.
Meantime, even a gadget to keep blood pressure at bay is being tested. In
March, doctors at the University of Rochester Medical were the first in the
nation to implant the Rheos, a battery-operated generator that
activates the body's natural blood pressure regulation systems. Much
like a pacemaker regulates heart rhythm, this device stimulates nerves in
the carotid arteries to tell the brain to reduce blood pressure. Bisognano
is part of the team that is testing the device.
Still, preventing hypertension in the first place is a far better thing
than having to rely on medicines or machines, clinicians agree. That is why
the National Hypertension Association (NHA) has focused on basic research
and education.
NHA researchers have shown, for example, that salt-sensitive rats get
high blood pressure when exposed to excess salt. "But the salt resistant
ones are not bothered by it at all; their kidneys get rid of it," noted Dr.
William M. Manger, NHA chairman and clinical professor of medicine at New
York University Medical Center. At least in salt-sensitive rats, it appears
that excess salt to the brain causes hypertension, he said. How that will
play out in humans is still unknown, but investigators are hopeful.
The NHA also sponsors VITAL (Values Initiative Teaching About Lifestyle),
a rapidly expanding school-based initiative to change the lifestyle and
behavior of young children. It focuses on nutrition and exercise, a much
broader agenda than hypertension alone. But it fills a critical gap,
according to Manger, author of the not-yet-released book, Our Greatest
Threats Protect Your Children and Yourself, focusing on preventing
unhealthy lifestyles.
"I think this VITAL program is the best thing we could do for our
nation," he said.
More information
The American Heart Association has more
facts about
high blood pressure.
(SOURCES: John D. Bisognano, M.D., Ph.D.,
associate professor, medicine, and director, cardiac rehabilitation and
clinical preventive cardiology, University of Rochester Medical Center,
Rochester, N.Y.; William M. Manger, M.D., Ph.D., chairman, National
Hypertension Association, and clinical professor, medicine, New York
University Medical Center, New York City; May 2003 Seventh Report of the
Joint National Committee on Prevention, Detection, Evaluation, and Treatment
of High Blood Pressure; LeadDiscovery, Sussex, England; American Heart
Association, Dallas; Caduet Web site, Pfizer Inc., New York City; April 1,
2005, press release, University of Rochester Medical Center)
SOURCE:
http://www.healthfinder.gov/news/
