The FDA, under attack from Congress for its handling of the antibiotic Ketek, is now mandating new warnings for the drug, but may not have silenced its critics.

The FDA has announced that it has approved a new label for the sanofi-aventis drug containing a strengthened, boldfaced warning about the potential for liver injury. The warning tells physicians to monitor patients carefully for signs of liver injury, which can occur very rapidly -- in some cases, after the patient has taken just a few doses of the drug. Patients with myasthenia gravis are at heightened risk, according to the warning.

There have been 12 cases of acute liver failure connected to Ketek, resulting in four deaths and one liver transplant, and 23 cases of acute serious liver injury, Gerald DalPan of CDER's Office of Epidemiology and Surveillance, said. When the drug was approved, he said, premarket studies showed the risk of liver injury with Ketek to be similar to that of other antibiotics. But there have been charges of data falsification, prompting Sen. Chuck Grassley (R-Iowa), chairman of the Senate Finance Committee, and several other prominent members of Congress to condemn the FDA's handling of the matter.

A statement issued by Grassley's office shortly after the FDA announcement indicates he is not satisfied with a strengthened warning. "Ketek is another example where the FDA accommodated a drugmaker and turned a blind eye to serious safety concerns," he said. "The FDA has become a great facilitator, giving the drugmakers what they want." (http://www.fdanews.com/did/5_128/)