Charlotte, N.C. ? A new antibiotic used to treat respiratory infections has been linked to severe liver disease that killed one Charlotte-area patient and caused another to need a liver transplant last year.

A third patient developed severe liver problems but got well once he stopped taking the drug, Ketek, according to doctors at Carolinas Medical Center.

Three cases of drug-induced liver disease in one hospital struck doctors as unusual, and they wrote about it for the Annals of Internal Medicine, a medical journal that published their report on its Web site last month.

“Is this just an incredible aberration or is there something more about this drug?” asked Dr. John Hanson, a co-author and member of CMC’s liver transplant team. “We’ve raised more questions than we’ve answered at this point.”

The CMC doctors also reported the cases to the U.S. Food and Drug Administration, which issued a public health advisory Jan. 20 warning doctors to monitor patients on Ketek.

If patients notice any yellowing of their eyes or skin, they should get medical attention, the FDA said.

The significance of having three cases in one city, the advisory says, is unclear.

Ketek was approved by the FDA in 2004 for treatment of bacterial infections, such as bronchitis, sinusitis and pneumonia.

Marketed by the French drug company Sanofi Aventis, the drug is effective against bacteria that have become resistant to older antibiotics.

None of the three patients was taking other drugs, and tests on the livers of two of the three showed the damage was caused by medicine, not alcohol.

“We advise caution in prescribing this drug pending further surveillance,” the Charlotte doctors concluded.

A Sanofi Aventis spokeswoman said the company reviewed these and other reported cases and concluded that they “do not alter the drug’s current safety profile.” She added that infrequent cases of liver damage have been noticed in other antibiotics on the market.

By publicizing their cases, the Charlotte doctors hope to hear from other doctors or patients who have observed similar symptoms.

So far, Hanson said, he has been contacted by two doctors who had patients on Ketek who developed liver problems. They both got better, he said.

The FDA’s advisory said patients on Ketek should not stop taking the drug if they aren’t having unusual side effects.