The FDA today announced revisions to the labeling of Sanofi-Aventis’ antibiotic Ketek, restricting use of the drug only to treat pneumonia but not less serious bacterial infections including bronchitis and sinusitis, as previously indicated.“The agency has determined that the balance benefits and risks no longer support approval of the drugs for these indications,” the FDA said in a statement. The agency also Ketek’s labeling would bear a strong new “black box” warning outlining the drugs risks and safe use. The warning states that Ketek should not be used in patients with myasthenia gravis, a disease that causes muscle weakness. The labeling changes are in line with the December recommendations of an FDA advisory committee which suggested Ketek should no longer be marketed for bronchitis or sinusitis, saying the drug’s risks outweigh its benefits for these infections. Advisory committee members also recommended that Ketek’s labeling should include a “black box” warning to address risks associated with the drug.Ketek labeling already warns of the drug’s risk to the liver. An FDA review released in December cited 13 reports of liver failure in patients treated with the drug. The FDA announce the Ketek labeling changes on the eve of a House subcommittee hearing on drug safety to examine irregularities in the approval of Ketek. The FDA’s handling of Ketek is also under investigation by the Senate.