03/26 14:40 Company, FDA argue danger of diabetes drug
By Lisa Richwine
BETHESDA, Md., March 26 (Reuters) - Twenty-eight people have died
after taking the controversial diabetes drug Rezulin, the U.S. Food and
Drug Administration said on Friday.
The drug seriously damaged the livers of another 12 people, seven of
whom had to have liver transplants, an FDA expert told a hearing on
the drug.
The FDA is considering tighter restrictions on the drug, made by
Warner-Lambert Co's <WLA.N> Parke-Davis unit, after reports that it
could cause serious liver damage.
But the company argued with an FDA expert on just how dangerous
the drug is, and about how many people risk liver damage from taking
it.
Rezulin, known generically as troglitazone, is used mostly to treat
type-II diabetes, which usually develops in adulthood and which causes
the body to resist the effects of insulin. The drug helps the body
respond better to the effects of other drugs for diabetes.
Warner-Lambert argues that taking the drug is worth the risk for people
with diabetes, which can cause serious complications like blindness
and limb loss.
About 15 million Americans suffer from type-II diabetes, and more than
1.4 million people have taken Rezulin since its launch in March 1997.
David Graham of the FDA's office of post-marketing drug risk
assessment said 40 cases of acute liver failure had been caused by
Rezulin. Of these, 28 people died, he told an FDA advisory committee
hearing evidence about the drug before making recommendations to
the agency.
There were another three cases of uncertain outcome, he said.
Parke-Davis also says 28 people have died because of Rezulin's
effects on the liver. "We see really no discrepancy between the
agency's numbers and our numbers," Dr. Robert Zerbe of Parke-Davis
said.
But the company did dispute Graham's assessments of how risky the
drug is.
Graham estimated the 40 cases of liver failure represented only 10
percent of the actual number of cases, because doctors do not always
report them.
Factoring in possible under-reporting, Graham said the risk of liver
injury for a patient taking Rezulin for six months was about one in
1,800. "The longer you stay on Rezulin, the higher the risk you
accumulate," he told the panel.
But there is only data for about eight months. He said he does not
know how dangerous the drug would be after someone took it for a
year.
"We don't have the data. We don't know the answer to that -- but what
we see isn't reassuring," he told the panel.
Graham's figures were "highly speculative," said company spokesman
Stephen Mock. Parke-Davis estimates the risk is closer to 1 in 45,000
patients.
It said the incidence in liver-related deaths had decreased since the
latest labeling change. Last year the company warned doctors and
other health care workers that the drug could damage the liver, and
patients must now take regular liver enzyme tests.
Parke-Davis wants to test Rezulin for its possible effects in preventing
diabetes, but Glaxo-Wellcome, <GLXO.L> which sold the drug in
Britain, suspended sales in December 1997. U.S. government
researchers also stopped their tests of Rezulin to prevent diabetes
because of the concerns. Rezulin faces some stiff competition, even if
the FDA does not further restrict its use.
Two new drugs in the same class as Rezulin are expected to hit the
market in the next year -- SmithKline Beecham Plc's <SB.L> Avandia,
known generically as rosiglitazone, and Eli Lilly & Co.'s <LLY.N>
Actos, known as pioglitazone |
