The Food and Drug Administration warned Tuesday that Amylin Pharmaceuticals ( AMLN) Byetta, a type II diabetes drug, may be associated with cases of acute pancreatitis.

The agency issued an alert, saying that it's received 30 postmarketing reports of acute parncreatitis in patients taking Byetta, and that health care professionals should instruct patients taking the injection to seek prompt medical care if they experience symptoms such as unexplained persistent severe abdominal pain and possibly vomiting, and immediately discontinue the drug if the condition is suspected.

The FDA said Amylin has agreed to include information about acute pancreatitis in the precautions section of the product label. The San Diego-based company has a collaboration agreement with Eli Lilly ( LLY) and Alkermes ( ALKS) to develop a sustained release version of Byetta.

Amlyin, which reports third-quarter earnings Wednesday, was falling $2.44, or 4.9%, to $45.50 in recent trading Tuesday; Eli Lilly was down 73 cents, or 1.3%, at $57.22; and Alkermes fell 64 cents, or 3.6%, to $16.85.