Bristol-Myers to Stop Selling Heart Medicine : Health: Studies had linked Enkaid to increased deaths among people being treated for irregular heartbeats.

Bristol-Myers Squibb Co. said Monday that it will stop selling a drug linked to increased deaths among people being treated for irregular heartbeats.

The decision comes more than two years after studies showed that the medication could be dangerous for some patients.

Enkaid, a drug to treat cardiac arrhythmia, will no longer be marketed through ordinary channels, although it will be available free through their doctors to patients who are already using it successfully, a Bristol-Myers spokeswoman said.

The company stressed that patients should not discontinue use on their own but consult their physicians.

Though the drug remains useful for treating patients with severe, life-threatening cardiac arrhythmia, according to Bristol-Myers Squibb, it was linked to high death rates when used to treat patients for non-life-threatening irregular heartbeats in a study in 1989.

The study at the National Heart, Lung and Blood Institute found that of 432 patients treated for cardiac arrhythmia, there were 44 deaths among those taking Enkaid, compared to 19 deaths among those taking placebos.

After the study results were published, the FDA tightened guidelines on selling Enkaid, strictly limiting its use to patients with life-threatening arrhythmia. Last month, another anti-arrhythmia drug, Ethmozine, manufactured by Du Pont Pharmaceuticals, was also linked with high mortality rates in continuing studies at the National Heart, Lung and Blood Institute.

Du Pont has sent a letter to 100,000 doctors, informing them of the results, according to the institute.