Eli Lilly & Co. and Amylin Pharmaceuticals Inc.'s diabetes drug Byetta on Monday received a federal warning after the drug was linked to deaths in two patients with an inflamed pancreas and four other hospitalizations.

The U.S. Food and Drug Administration (FDA) now plans to strengthen warnings about life-threatening pancreas problems linked to the type 2 diabetes drug. Those who died were among six Byetta users who entered the hospital since October because of a condition known as acute pancreatitis (inflammation of the pancreas with bleeding). Their Byetta treatment was stopped and the four survivors were still recovering, the FDA posted on its website.

The drug, available in the U.S. since June 2005, is given by injection. It should be promptly discontinued if pancreatitis is suspected and not restarted if pancreatitis is confirmed, noted the FDA.

Amylin, of San Diego, and Indianapolis-based Lilly agreed to warn of the risk of pancreatitis in October last year, after the FDA noted 30 reports of acute pancreatitis in Byetta users.

However, the latest deaths are linked to hemorrhagic pancreatitis (inflammation of the pancreas with bleeding) or necrotizing pancreatitis (in which the inflamed pancreas destroys itself). The FDA said its working with Eli Lilly and Amylin to add more prominent warnings in the product label around the risk of these severe forms of pancreatitis.