WASHINGTON — Pfizer Inc.'s painkiller Bextra will come with a new warning about the possibility of heart attacks and blood clots in patients who have just had heart bypass surgery, the Food and Drug Administration said Thursday.
The FDA said it still considered the drug beneficial when taken for approved uses, such as relieving arthritis pain.
The "FDA believes that, based on what we know now, the overall benefit of Bextra outweighs the risk when used in properly selected patients as directed in the approved labeling," the agency said in a statement posted on its website.
A Pfizer study of more than 1,500 patients who had just had heart bypass surgery found that patients treated with Bextra for pain were more likely to have heart attacks, strokes and blood clots in the legs or lungs than others who took a placebo, the agency said.
Reacting to the FDA's announcement, Sen. Charles E. Grassley (R-Iowa) said he would ask the agency for detailed information on how it evaluated the risks of taking Bextra and made its decisions about how the painkiller should be regulated. Grassley said he also was asking Pfizer for information on how it communicated with the FDA about Bextra's heart risks.
Bextra was one of five drugs identified as posing serious risks by FDA reviewer Dr. David Graham in testimony before Grassley's Senate Finance Committee last month.
"When the FDA approves a drug, you should be able to bank on it," Grassley said in a statement. "If a drug isn't safe, you should know the FDA will take it off the market."
Grassley stopped short of calling for a recall of Bextra.
Bextra is not approved for treating pain following heart bypass surgery. The new warning specifically urges doctors not to use the drug in that setting.
The updated Bextra label also includes a stronger warning, now highlighted in a black box, about the possibility of a rare, potentially fatal skin reaction known as Stevens-Johnson Syndrome. As of November, the FDA had received 87 reports of that condition and other skin reactions. Thirty-six of the patients were hospitalized and four died, the FDA said.
Bextra is getting close attention from regulators because it is in the same family of drugs as Merck & Co's arthritis pill Vioxx, which was pulled from the market Sept. 30 after a study showed the drug doubled the chance of heart attack and stroke when used for more than 18 months. Both drugs are so-called COX-2 inhibitors.
Bextra, which was launched in 2001, had sales last year of $687 million.
Pfizer spokeswoman Mariann Caprino said the company had no comment on the heart warning. "There's no new information in the label. It's all been previously shared with the medical community," she said.
Pfizer announced in October that two small clinical trials of Bextra showed heart bypass patients had an increased risk of stroke and heart attack.
The company also said at the time it was adding the skin-related warning to the drug's packaging.
The FDA is planning a public advisory committee meeting in February to discuss safety concerns with Bextra and other COX-2 inhibitors, including another Pfizer painkiller, Celebrex.