Debate Continues Over Type 2 Diabetes Meds
Reported September 12, 2007
ORLANDO, Fla. (Ivanhoe Newswire) -- U.S.
Food and Drug Administration warnings on the labels of Avandia (rosiglitazone),
a glycemic control drug prescribed to type two diabetics, are not strong enough,
according to some researchers.
After reviewing research this summer, an FDA panel voted to keep Avandia on the
market with a "black box" warning, advising doctors to watch patients for heart
failure and advising against prescribing the medication to people with serious
or severe heart failure.
"The FDA's black box is too little, too late," researcher Sonal Singh, M.D.,
told Ivanhoe. He and his colleagues from Wake Forest University School of
Medicine in Winston-Salem, N.C., report their new study of the long-term effects
of Avandia reveals the medication is associated with increased risk of heart
attack and heart failure.
"They say avoid it in stage three and stage four heart failure patients. So,
what does that mean for stage one and two? We should use it? In Europe, it's
been contraindicated in one, two, three, four, period," said Dr. Singh. "I think
they need to give clear, crisp information. That's our advice: avoid it in
patients at risk for cardiovascular events."
The new findings are similar to those of a study reported earlier this year.
Researchers from the Cleveland Clinic compiled data from previous studies on
Avandia and found the drug is linked to a significant increase in the risk of
heart attack and a slight increase in the risk of cardiovascular death. That
study did not include information on long-term effects or what role dosage had
in increasing risks.
For the new study, researchers compiled data from four studies involving more
than 14,000 patients. The studies had randomly assigned participants with type 2
diabetes or impaired glucose tolerance taking Avandia, another type of diabetes
drug, or a placebo. Those using Avandia had a 42-percent increased risk of heart
attack and double the risk of developing heart failure. The drug had no effect
on the number of people dying from cardiovascular causes.
"There is no need for physicians, health plans or patients to wait for
regulatory action," Curt Furberg, M.D., Ph.D., a co-author of the report, was
quoted as saying. "On the contrary, they should take prompt action and restrict
the use of Avandia, especially since safer alternatives are available."
A drug in the same class as Avandia, pioglitazone (Actos), is the subject of
another study published this week. Researchers from the Cleveland Clinic report
the drug reduces the risk of heart attack, stroke and death, while it increases
the risk for serious heart failure.
Analyzing the results of 19 studies, researchers found heart attack, stroke or
death occurred in 4.4 percent of patients taking Actos and 5.7 percent of
patients taking a control medication.
"These findings suggest that the net cardiovascular benefit with pioglitazone
therapy is favorable, with an important reduction in irreversible ischemic
events that is not attenuated by the risk of more frequent heart failure
complications," write study authors.
Dr. Singh, however, disagrees with this conclusion. "What I take from that is
pioglitazone increases heart failure without any effect on mortality or benefit
on mortality and myocardial infarction [heart attack]."
Both medications need further examination to reveal their impact on vision loss
and fractures in women, two side effects also linked to Avandia, said Dr. Singh.
However, he said clinical trials of the drug would be unethical, given the
evidence pointing to its harmful effects.
SOURCE: Ivanhoe interview with Sonal Singh, M.D.; The Journal of the American
Medical Association, 2007;298:1180-1188, 1189-1195
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