Drugs May Cause Heart Failure
Two popular drugs used to treat type-2
diabetes can cause fluid buildup and heart failure in some patients,
U.S. doctors said.
The drugs, sold under the brand
names Avandia and Actos, caused heart failure and a buildup of
fluid in the lungs in six men with poor kidney or poor heart function,
the researchers said.
The findings, published in the
Mayo Clinic Proceedings, are another potential blow to the newest
class of diabetes drugs, the thiazolidinediones or glitazones.
The first drug in the class, Rezulin,
was pulled from the market in March 2000 after about 100 people
who took it died from acute liver failure or had to have liver
Pfizer Inc., which owns Rezulin
as part of its purchase of Warner-Lambert company, is fighting
off thousands of lawsuits alleging that Warner-Lambert failed
to inform the public of the drug's health risks.
Tuesday's report from a team at
the University of Texas Southwestern Medical Center at Dallas
may support lawsuits by other patients against GlaxoSmithKline
Plc, which makes Avandia, known generically as rosiglitazone.
The six men whose cases are detailed
in the report took either Avandia or Actos, known generically
as pioglitazone and jointly marketed by Japan's Takeda and Eli
Lilly $ co. Inc. .
An estimated 6 million Americans
take one or the other of the drugs. About 16 million Americans
have type-2 or adult-onset diabetes.
Many do not need to take insulin
but can take a variety of drugs including metformin and drugs
in a class called sulfonylureas. The glitazones are gaining in
popularity because they restore the body's ability to respond
"Many physicians are prescribing
these drugs in patients with chronic renal insufficiency because
a first-line diabetes drug, metformin, is not recommended for
them," said Dr. Abhimanyu Garg, a professor of internal medicine
at UT Southwestern who worked on the study.
"These new data suggest that such
patients may be at particularly high risk of developing heart
failure. These are newer agents, and we need to become more familiar
with their side effects so that we can use them judiciously."
All six patients showed up at the
Veterans Affairs Medical Center in Dallas with shortness of breath,
weight gain and swelling in the legs. "These are the signs and
symptoms of congestive heart failure and pulmonary edema," Garg
said in a telephone interview.
Pulmonary edema is a potentially
fatal condition in which fluid builds up in the lungs because
the heart is not working efficiently.
"All physicians are aware that
these drugs can cause swelling of the legs. But whether they could
cause this serious complication was not very clear," Garg said.
The drugs increase blood volume,
and doctors are told not to use them in patients with the most
advanced heart dysfunction. But Garg said these six men all had
mild to moderate heart and kidney problems.
"It seems to me these drugs may
not be safe in such patients. They may not be able to tolerate
fluid overload induced by such drugs," he said.
Luckily, he said, the patients
were treated, taken off the glitazone drugs and all recovered.
In June, 32 diabetes patients in
Texas and California sued GlaxoSmithKline, claiming the company
failed to warn them of serious side-effects of Avandia.
But a spokeswoman for GlaxoSmithKline
said Avandia's U.S. label warns that the drug can cause fluid
retention that can cause heart failure or worsen it.
Reference Source 89