WASHINGTON, Feb. 12 (UPI) -- The U.S. Food and Drug Administration curbed the approved uses of the Sanofi-Aventis antibiotic Ketek Monday and also said it would issue new safety warnings for the drug.
The move is the latest wrinkle in years of maneuvering over the drug, which has been the subject of a pair of FDA reviews and a U.S. Senate investigation.
The antibiotic would no longer be indicated to treat sinusitis and bronchitis, two generally non-dangerous upper respiratory tract infections. It will remain approved for the treatment of community-acquired pneumonia.
The decision was "the result of a comprehensive analysis of risks and benefits" of Ketek, said John Jenkins, head of the FDA's Office of New Drugs.
Those risks include liver toxicity, a problem that increasingly concerned FDA scientists and industry watch dogs since Ketek gained U.S. approval in 2004. An analysis commissioned by the agency late last year found 35 cases of severe injuries that analysts said were likely caused by Ketek.
U.S. doctors have written an estimated 6 million Ketek prescriptions. But experts and regulators worried that the risk of liver problems, while rare, may not be worth Ketek's limited benefits.
The drug was never shown to be superior to other antibiotics at treating infections but was approved under an FDA policy intended to expand the number of antibiotics available to combat drug resistance.
Ketek's label was altered in June 2006, warning that it carries a risk of liver damage.
Now, a new boxed warning in Ketek's labeling will warn doctors and consumers that the drug should not be used in patients with a muscle disorder called myasthenia gravis, the agency said. Sanofi-Aventis will also alert doctors of the changes and begin distributing patient information guides, the company said.
In a statement, the France-based company said Ketek remains "an important option" for doctors.
Sanofi-Aventis posted $58.3 million in Ketek sales in the first nine months of 2006, said company spokeswoman Melissa Feltmann.
"I think it's premature to speculate on the exact impact" of Monday's announcement, she said.
The issue over Ketek's safety has helped ramp up Congress's scrutiny of the FDA. A December Senate Finance Committee report concluded that the agency erred in 2003 when it did not inform expert advisers reviewing Ketek that a large safety study was flawed by researcher misconduct.
Jenkins referred to the episode Monday as "a learning experience." If the agency encounters a similar situation in the future, "it's possible we would take a different decision at that point," he said.
Sen. Charles Grassley, R-Iowa, said the FDA had been held accountable for its approval of Ketek.
"Now the uses for Ketek are limited, and the public is safer and better informed," said Grassley, whose staff issued the Senate report.
The agency's handling of Ketek is likely come up in hearings on the agency's practices scheduled for Tuesday in the House of Representatives.
Les Funtleyder, a health industry analyst with Miller Tabak & Co. LLC, said the narrowed indications would probably not have a large impact on Sanofi's Ketek sales.
"I think at this point everyone is keenly aware of the baggage that comes along with Ketek. Anyone who prescribes it is probably aware, and it would be hard not to be aware," he said.
