The government is warning of potential heart problems associated with the use of the painkiller Bextra in people who have recently had heart bypass surgery.

The Food and Drug Administration said Thursday it is adding the warning to the labels of Bextra, as well as strengthening the label warnings that there is the possibility of severe skin reactions with the drug.

FDA said in a statement that it was adding heart the warning to the Bextra label because “results from a new study of more than 1,500 patients who had just had cardiac surgery show that patients treated with Bextra for pain were more likely to have heart and blood clotting problems than other patients who did not receive any drug.”

The problems included heart attack, stroke and blood clots in the legs and the lungs, the FDA said.

It said the new label will indicate Bextra is not indicated for treatment of pain immediately following coronary bypass graft surgery.

Bextra is a type of painkiller known as a cox-2 inhibitor. These drugs have become popular because of their effectiveness in treating the pain of arthritis and other ailments.

However, Vioxx, another cox-2 inhibitor, was recently pulled from the market because of concerns about heart attack risk among users of the product. FDA is convening a panel in February to review all cox-2 inhibitors.