Antibiotic Gets Stronger Liver Warning
FDA Warns of Potentially Fatal Liver Failure With Antibiotic Ketek
June 29, 2006 -- The FDA today ordered stronger warnings of potentially
failurewith the antibiotic Ketek
Ketek is approved to treat acute bacterial sinusitis, mild to moderate
pneumonia, and acute worsening of
The stronger warning is based on the FDA's review of Ketek's postmarketing
adverse event reports. Those records show 12 cases of acute liver failure --
four of which were fatal; a fifth required a liver transplant. There were also
an additional 23 cases of acute liver injury.
In some cases, those liver problems started "even after a few doses of
the Ketek and progressed rapidly," Gerald DalPan, MD, told reporters in a
teleconference. DalPan works in the FDA's Office of Epidemiology and
Surveillance Center for Drug Evaluation and Research.
Ketek's new label will advise doctors and patients to watch carefully for
signs and symptoms of liver injury while taking Ketek and "to discontinue
the drug promptly if any signs or symptoms of liver injury are to develop,"
the FDA's John Jenkins, MD, told reporters in the teleconference. Jenkins
directs the Office of New Drugs at the FDA's Center for Drug Evaluation and
DalPan says the rate of reported liver events was 23 out of 10 million
prescriptions. That's an estimate based on reported cases and dispensed
prescriptions, not an incidence rate, because there may be unreported cases,
Ketek's new label will also note that there have been reports of fatal
worsening of the neuromuscular condition, myasthenia gravis. The FDA
knows of three reported deaths in myasthenia gravis patients taking Ketek,
according to DalPan.
DalPan says the myasthenia gravis patients who died while taking Ketek were
in their 70s and 80s and were taking Ketek for respiratory infection. The
myasthenia gravis deaths are "completely separate" from the liver
problems reported with Ketek, DalPan says.
When the FDA approved Ketek in April 2004, the drug's labeling included
precautions about liver injury and possible worsening of myasthenia gravis, as
with other drugs in its class.
"The statement about liver disease on the label has been upgraded from a
precaution to a warning and the label has generally been strengthened to
include a description of the sometimes rapid onset ... and the severity of the
liver injury," DalPan says.
The drug's previous warning about myasthenia gravis did not mention death
risk because no fatal cases were known at that time.
Ketek is made by Sanofi Aventis. Sanofi Aventis is a WebMD sponsor.