By Toni Clarke
Sept 27 (Reuters) - Pfizer Inc's antibacterial drug Tygacil increases the risk of death whether used as authorized by the U.S. Food and Drug Administration or for unapproved conditions, the agency warned on Friday.
Pfizer must place a warning inside a black box on the drug's label, indicating the risk is of the most serious nature. The FDA said the drug, which is usually given intravenously, should only be used when alternative treatments are not suitable.
The drug is approved to treat complicated skin and abdominal infections and community-acquired bacterial pneumonia. It is not approved to treat diabetic foot infection or hospital-acquired pneumonia.
In September 2010, the FDA issued a reminder to physicians that Tygacil carried a higher risk of death than other drugs used to treat infection. The agency said at the time it had analyzed pooled clinical trial data and determined that most deaths were related to progression of the infection.
The FDA said the increased risk of death was mostly seen in patients with hospital-acquired pneumonia, though it was also seen in patients with other types of infection. The agency updated the "Warnings and Precautions" section of the label to reflect risks.
Since issuing that 2010 notice, the FDA said it has analyzed data from 10 trials of patients who took Tygacil, known generically as tigecycline, only for FDA-approved uses. This analysis also showed a higher risk of death compared to other antibacterial drugs.
Public Citizen, a drug safety watchdog, which petitioned the FDA in 2011 to place a black box warning on Tygacil, said the FDA's action comes far later than it should have.
"The failure of the FDA to require a black box warning years ago is inexcusable," the group said in a statement.
According to the FDA, patients who took Tygacil for authorized uses had a 2.5 percent risk of death, compared with a 1.8 percent risk of death for those who took other antibacterial drugs.
A spokeswoman for Pfizer, Kimberly Bencker, said that "due to the increase in antibiotic resistance worldwide, Tygacil continues to be an appropriate treatment option for its approved indications."
In general, the deaths resulted from worsening infections, complications from infection or another underlying medical condition, the FDA said.
Tygacil was approved in the United States in 2005. It generated sales in 2012 of $335 million.
Pfizer's shares were up 34 cents, or 1.2 percent, at $28.86 in afternoon trading on the New York Stock Exchange.