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Pioglitazone and Rosiglitazone
Two commonly
prescribed diabetes drugs may cause heart failure and fluid buildup
DALLAS – Sept. 9, 2003 – Two diabetes
medications taken by more than 6 million Americans may lead to serious
side effects, including the onset of congestive heart failure and
pulmonary edema, according to researchers at UT Southwestern Medical
Center at Dallas.
In today's issue of the Mayo Clinic
Proceedings, the researchers report that the oral drugs pioglitazone
and rosiglitazone can cause or exacerbate heart failure and pulmonary
edema and should be avoided in patients with left ventricular
dysfunction (impaired pumping ability of the heart) or chronic renal
insufficiency.
Both medications – among a class of
drugs known as thiazolidinediones – are used for the treatment of
non-insulin dependent (type 2) diabetes mellitus, said Dr. Abhimanyu
Garg, professor of internal medicine, chief of the diabetes clinic at
the Dallas Veterans Affairs Medical Center, and the study's senior
author.
"Many physicians are prescribing these
drugs in patients with chronic renal insufficiency because a
first-line diabetes drug, metformin, is not recommended for them.
These new data suggest that such patients may be at particularly high
risk of developing heart failure," said Dr. Garg. "These are newer
agents, and we need to become more familiar with their side effects so
that we can use them judiciously."
Congestive heart failure, which affects
3 million Americans, is an imbalance in pump function in which the
heart fails to maintain adequate circulation of blood. The most severe
manifestation of congestive heart failure is pulmonary edema, or fluid
in the lungs. Patients with coexisting type 2 diabetes have an
increased mortality rate.
The researchers reviewed the records of
six patients with type 2 diabetes who were treated at the VA emergency
room after experiencing shortness of breath, weight gain and swelling
of the feet – all signs and symptoms of congestive heart failure and
pulmonary edema.
These symptoms developed after one to 16
months of therapy with pioglitazone or rosiglitazone. In three
patients, doses of these medications were increased three weeks to
three months prior to the onset of congestive heart failure.
The researchers provided follow-up care
to the patients during clinic visits.
After discontinuing the medications and
administering diuretics, the patients no longer exhibited the signs
and symptoms of congestive heart failure and pulmonary edema.
The Food and Drug Administration
approved rosiglitazone and pioglitazone in 1999. The prescribing
information indicates that the drugs should not be used by individuals
with New York Heart Association (NYHA) Class III and IV status,
particularly in combination with insulin.
"Our data indicates that patients with
NYHA Class I or II cardiac status may also be at risk of
thiazolidinedione-associated cardiac failure," said Dr. Asra Kermani,
the study's lead author and an assistant professor of internal
medicine at UT Southwestern who is an attending physician at the VA
diabetes clinic.
The New York Heart Association
functional classification for patients with heart failure is used to
characterize patients' limitation from left ventricular failure. Class
I represents no limitation of physical activity; Class II, slight
limitation of physical activity; Class III, marked limitation of
physical activity; and Class IV, unable to carry on any physical
activity without symptoms.
Because the mean age of the patients in
the study was 69, additional studies need to be undertaken to identify
the patient groups at risk for these complications, the researchers
noted.
"We need further studies to understand
the mechanism by which thiazolidinediones cause fluid overload and
deterioration in cardiac status," Dr. Kermani said.
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