FDA Weighs Fate of Antibiotic Ketek
Expert Panel Hears Testimony on Safety of Controversial Drug
Dec. 14, 2006 -- An FDA panel is getting ready to decide whether to
recommend that a widely used antibiotic be taken off the market.
The drug, known as Ketek, is used to treat respiratory tract infections like
bronchitis, sinusitis, and pneumonia.
Doctors have written an estimated 6 million prescriptions for the drug since it
was approved in April 2004.
But the FDA is reconsidering that approval because of reports suggesting the
drug could carry a higher risk of severe liver failure and other
dangerous side effects than similar antibiotics.
A panel of experts is holding two days of hearings on Ketek safety. The
hearings began Thursday. A recommendation is expected to be made on Friday.
This week, a Senate committee investigation blasted agency officials for
their handling of Ketek's original approval. A committee report accuses
officials of withholding details of a tainted Ketek safety study from the panel
in 2003 as it was advising the FDA on the drug. The episode has led some FDA
scientists to sharply criticize the decision to approve Ketek.
Ketek was never shown to be more effective than other antibiotics at curing
infections. The FDA requires only that new antibiotics show evidence of
"noninferiority" to existing drugs. The rationale, experts say, is to
help ensure a steady stream of available drugs to combat antibiotic
The drug was judged to be as safe as other antibiotics when it was approved
in 2004, based on premarket studies. But reports of a possible pattern of liver
injuries while the drug has been sold in the U.S. prompted the FDA to reopen
deliberations over Ketek.
"Ketek is being triggered because of the safety concerns that have
arisen," said John Jenkins, MD, director of FDA's Office of New Drugs.
Reports of Liver Injury
Sanofi Aventis, which manufactures Ketek, reported to the FDA 212 cases of
liver injury in patients who took the drug over the last two and a half years.
Company and agency experts characterize the reports as initial signals of both
minor and severe injuries that cannot be reliably blamed on the drug. Sanofi
Aventis is a WebMD sponsor.
Company officials argued Thursday that the injuries occurred in 6 million
uses of Ketek and that the drug, known generically as telithromycin, carries
about the same overall risk as similar antibiotics.
"It's a drug with a signal of [liver] injury, but we always have to put
it in perspective," said James H. Lewis, professor of medicine at
Georgetown University, who testified on behalf of the company. "Take your
pick of antibiotics, they are all associated with liver injury."