An antibiotic proposed as a treatment for acute sinus infections should be studied further because of serious skin reactions associated with its use, federal health officials said in documents released Monday.

When compared with other antibiotics used to treat minor infections, the incident of serious rashes has Food and Drug Administration officials concerned about the safety of the drug, Factive or gemifloxacin. The regulatory agency released the documents ahead of a Tuesday meeting of outside experts asked to consider the drug.

The FDA approved the drug in 2003 to treat pneumonia and acute bronchitis. Its manufacturer, Oscient Pharmaceuticals Corp., is seeking expanded approval to treat acute bacterial sinusitis as well. In 2002, the FDA had declined to approve that use.

Real-world use of Factive has shown what clinical trials previously revealed: the risk of rashes associated with the antibiotic appears to be greater when compared with that seen in other, similar antibiotics, according to the FDA documents.

In the documents, Oscient said its drug "represents an important additional therapeutic option for treatment" of acute bacterial sinusitis. Factive offers clear benefits and has a safety profile equivalent to other antibiotics. Oscient said.

At Tuesday's meeting, the FDA will ask members of its anti-infective drugs advisory committee whether the benefits of Factive outweigh its risks as a treatment for acute sinusitis. The FDA isn't required to follow the advice of its outside panels of experts, but usually does.

If the panel fails to endorse the drug, the FDA will ask whether further study could support the expanded use of the drug.

FDA briefing documents show that some within the agency already think more study is needed, given the risk of skin reactions associated with the drug: "The magnitude of the benefit gained from the use of gemifloxacin for the indication under discussion (acute bacterial sinusitis) needs to be clearly defined to weigh the magnitude of this drug-related risk," FDA medical officer Dr. Andrew Mosholder wrote in a Sept. 5 memo released Monday.