FDA Warning of Byetta Pancreatitis Side Effects Contradicted by New Studies

New research suggests that there may not be a correlation between the diabetes drug Byetta and acute pancreatitis, raising questions about whether the drug caused prior reports of severe necrotizing pancreatitis and hemorrhagic pancreatitis that prompted an FDA warning last year.

Two studies were announced earlier this month at a conference of the American Diabetes Association (ADA). One was an independent study done by Medco Health Solutions, Inc., and the other was sponsored by Byetta’s manufacturers, Amylin Pharmaceuticals, Inc. and Eli Lilly & Co. Neither study showed any substantive difference between Byetta (exenatide) and other anti-diabetes therapies in the risk of developing pancreatitis.

The studies comes on the heels of an FDA warning issued in August 2008 that warned healthcare providers about six reports of severe pancreatitis among Byetta users, including two deaths. The drug makers later acknowledged that they were also aware of an additional four pancreatitis deaths linked to their medication.

Byetta is a type 2 diabetes drugs that is used to control blood sugar levels. It is part of a class of medications known as incretin mimetics, which imitate natural hormones that lower blood glucose levels.

The manufacturers’ retrospective cohort study focused on nearly 260,000 patients, using data from health insurance claims databases. The study found that the use of Byetta was “not associated with an increased rate of acute pancreatitis compared to the other antidiabetes medications,” according to a June 7 press release.

The Medco Health study looked at pharmacy and medical claims of 123,621 people with type 2 diabetes who were not using insulin, and found that only .44 percent of Byetta users suffered acute pancreatitis. That compared with .39% of those who used neither drug.

Pancreatitis causes inflammation of the pancreas resulting in symptoms of nausea, vomiting, severe pain in the upper abdomen and back, a rise or fall in blood pressure, increased heart and respiratory rates.

Information about potential pancreatitis side effects of Byetta was added to the drug’s warning label in 2007, after the FDA warned that at least 30 cases of acute pancreatitis had been associated with use of the diabetes drug. Following the 2008 FDA warning, analysts speculated that the FDA was considering a “black box” warning about the potential Byetta pancreatitis risk, which would be the strongest warning that could be placed on a prescription medication.

Amylin and Eli Lilly say they are still investigating the relationship between Byetta and the cases of pancreatitis discovered by the FDA. The Medco Health research is the first study that was not funded by the drug makers that contradicts the prior concerns about pancreatitis and Byetta.