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 agency 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 the drug only for FDA-approved uses. This analysis also showed a higher risk of death compared to other antibacterial drugs.
In general, the deaths resulted from worsening infections, complications from infection or another underlying medical condition, the agency said.
Tygacil was approved in the United States in 2005. It generated sales in 2012 of $335 million.
Pfizer did not immediately respond to a request for comment.
The drugmaker's shares were up 42 cents, or 1.5 percent, to $28.94 in midday trade on the New York Stock Exchange.