'Risky' Diabetes Drugs May Help
Heart Failure
February 09, 2005
By Jennifer Warner
Despite Warnings, Diabetes Drugs May Lower Death
Rate in People With Heart Failure
Many people with ailing hearts and diabetes may be
missing out on the potential benefits of two common
types of diabetes drugs because the drugs are considered
too risky for people with heart failure.
A new study shows that the drugs, which include a class
called thiazolidinediones (such as Avandia and Actos)
and metformin (sold under the names Glucophage, Fortamet,
and Riomet), may reduce the risk of death by as much
as 13% in people with heart failure and diabetes.
But the FDA and some health groups, including the American
Heart Association and American Diabetes Association,
warn against using the drugs in this high-risk group.
"We did not find any evidence of significant harm
with these agents and found that patients who received
prescriptions for them at hospital discharge actually
had significantly lower mortality rates," says
researcher Frederick Masoudi, MD, MSPH, assistant professor
of medicine at Denver Health Medical Center.
But researchers say it's too soon to recommend abandoning
current recommendations until further studies can confirm
these results.
The FDA advises against using thiazolidinediones in
people with advanced heart failure symptoms and requires
a "black box" warning -- the agency's strongest
type of warning -- in the drug's prescribing information.
Package inserts on metformin also warn against the use
of this drug in most people with heart failure.
Those warnings stem from concerns about the risk of
fluid retention with thiazolidinediones, a common complication
of heart failure, and lactic acidosis with metformin.
Lactic acidosis is a rare but potentially fatal side
effect of metformin that occurs when the tissues of
the body do not get enough oxygen.
Researchers say the treatment of diabetes in people
with heart failure is controversial, and doctors increasingly
prescribe these "risky" drugs to patients
with heart failure and diabetes despite those warnings.
Both thiazolidinediones and metformin are known as
insulin-sensitizing drugs because they are thought to
work by increasing the body's sensitivity to insulin,
which helps regulate blood sugar levels.
Should High-Risk Patients Take the Diabetes
Drugs?
Researchers say many doctors may resort to using these
drugs in their high-risk patients with heart failure
because the drugs have been shown to be effective in
getting blood sugar levels under control. Blood sugar
control may also be considered more difficult to attain
with the alternatives, such as sulfonylureas and insulin
injections, in people with advanced disease.
In this study, researchers followed 16,417 Medicare
patients with diabetes who were discharged from the
hospital after treatment for heart failure.
Researchers divided the patients into groups based
on their diabetes treatments and then compared the rates
of death and readmission to the hospital.
After one year of follow-up, the study showed that
the risk of death from all causes was about 13% lower
among the 2,226 patients who received thiazolidinediones
or metformin, compared with patients who received neither
drug.
Researchers found a small 6% increase in the risk of
readmission to the hospital for heart failure among
those taking a thiazolidinediones, which researchers
say may be a reflection of these drugs' propensity to
cause fluid retention. The risk of hospitalization for
heart failure was 8% lower among those treated with
metformin.
However, there was no difference in hospital admission
rates for any cause between those who received the "risky"
drugs and those who didn't.
The results appear in the Feb. 8 issue of Circulation:
Journal of the American Heart Association.
Too Soon to Change Recommendations
"The study highlights that there may be significant
benefits of these drugs in patients with diabetes and
heart failure, but we wouldn't advocate practicing outside
current recommendations for use of these medications,
says Masoudi. "It is a call for randomized trials
in populations such as this, which are at very high
risk for adverse outcomes from diabetes and from heart
failure."
The study also emphasizes the importance of closely
monitoring patients on thiazolidinediones.
Robert Rizza, MD, president-elect of the American Diabetes
Association, agrees.
"These are provocative data that further supports
the need for additional data from the ongoing randomized
studies to determine whether these drugs are of value
or not," says Rizza.
"These drugs have various actions, some of which
may be helpful to people with heart disease, and others
which may be harmful to people with heart disease,"
says Rizza, who is also professor of medicine at the
Mayo Clinic College of Medicine in the division of endocrinology,
diabetes, nutrition, and metabolism.
"When looking at population-based studies you
cannot determine cause from effect, and it's not clear
that there was improved survival because the people
who had potentially worse outcomes were not placed on
the drug because people were concerned about the action
of the drug," says Rizza. "That's why additional
studies are needed."
Source:http://my.webmd.com
|
