In the first human study of its kind, Dr. David Kass , a cardiologist
at Johns Hopkins University School of Medicine, showed in a paper last
fall in the journal Circulation that Viagra can suppress the effects
of stress hormones on the heart, a potential boon to many people with
heart disease.
In the study, 35 healthy male and female volunteers were given a drug
called dobutamine, which stimulates the heart much as the natural
hormone, adrenalin, does. Their hearts responded just as expected,
pumping harder and increasing cardiac output.
About 30 minutes later, Kass divided the group in two. Half got
Viagra, the other half, a placebo. Neither the doctors nor the
subjects knew who got which drug. About half an hour later, all
subjects got another dose of dobutamine. The hearts of people who had
gotten Viagra showed a smaller increase in contractions than those of
the people who got a placebo, suggesting that Viagra ``acts like a
brake on the heart."
In the penis, Viagra works through a chain of chemical reactions to
dilate blood vessels, the key to getting and maintaining an erection.
In the heart, Viagra works through the same chemical pathway, but the
result, instead of vasodilation, is a decrease in the heart's response
to stress. In another study, Kass's team has found that this decrease
in susceptibility to stress can actually reduce the thickening of the
heart muscle that often follows long-term high blood pressure, a
problem called cardiac hypertrophy.
Dr. Michael Mendelsohn , director of the Molecular Cardiology Research
Institute at Tufts-New England Medical Center, said that the new
evidence of Viagra's effect on the heart means ``it is time to start
studying the possibility of using Viagra as a heart drug."
Viagra and similar drugs such as Cialis and Levitra, said Kass, could
be taken once a day by people who have thickened heart walls, a
problem for 2.5 million Americans with congestive heart failure. A new
study using Cialis, which is longer-acting than Viagra, is expected to
begin in July. For now, doctors aren't recommending Viagra for heart
problems.
Labels: No Prescription, Online Pharmacy, Prescription Drugs
# posted by Network @ 10:13 PM
