By Andrew M. Seaman
People who take a certain type of diabetes drug to lower blood sugar levels may be at an increased risk of developing an inflamed pancreas, according to a new study.
Glucagonlike peptide 1(GLP-1) therapies that include exenatide - marketed as Byetta by an alliance between Bristol-Myers Squibb and AstraZeneca - and sitagliptin - marketed as Januvia by Merck - have been linked to pancreatitis before in studies on animals and small groups of patients, said the study's lead author.
"New therapies and risks are only evaluated when studies are done. We need to know (the drugs) are effective in lowering blood sugar, but we also need to know about risks," said Dr. Sonal Singh, from the Johns Hopkins University School of Medicine in Baltimore.
Pancreatitis, which can cause life-threatening complications, is rare but more common in people with type 2 diabetes. Singh said pancreatitis occurs in about three of every 1,000 diabetes patients.
The U.S. Centers for Disease Control and Prevention estimates that there are about 19 million Americans diagnosed with diabetes, and another 7 million who have the disease but don't know it yet.
In people with type 2 diabetes, the body doesn't produce enough insulin or is resistant to what it does produce.
For the new study, published in JAMA Internal Medicine, the researchers used data on 1,269 diabetes patients between the ages of 18 and 64 years old, who were admitted to U.S. hospitals with pancreatitis in 2005 through 2008.
They compared those to 1,269 other diabetes patients who were similar, but were not hospitalized with pancreatitis.
Overall, they found 87 of the diabetes patients with pancreatitis were taking GLP-1 therapies, compared to 58 of the diabetes patients without pancreatitis.
Singh told Reuters Health that the findings show the drugs are linked to a doubling of the risk of pancreatitis - about six cases per 1,000 diabetics.
"I won't say you should be alarmed about the findings, but it's something you should consider," he said.
Dr. Aaron Cypess, a staff endocrinologist in the clinic of the Joslin Diabetes Center in Boston, said the new study will not change how he treats patients, but it may influence him to go over his patients' risk factors for pancreatitis.
"For me personally it's not going to change my practice pattern in terms of stopping the drugs, but we may revisit whether you're showing any of the risk factors," said Cypess, who was not involved with the new study.
In a joint statement, the American Diabetes Association and the American Association of Clinical Endocrinologists also said the new findings should not change how doctors treat diabetes patients.
"The analysis is a retrospective study using data from an administrative database. This type of analysis is not considered as robust as a prospective randomized controlled clinical trial, the gold standard for evaluating treatments," the organizations wrote in the statement.
They continue that there are nine of those "gold standard" trials in the works that should provide answers soon.
The current study also had limitations, including that the diabetes patients hospitalized with pancreatitis tended to lead a less healthy lifestyle than those who did not have the condition.
In a commentary, Belinda Gier and Dr. Peter Butler from the University of California, Los Angeles, write supporters say the drugs are safe and offer some advantages over older medications.
Currently, the labels for Januvia and Byetta carry warnings that there have been reports of pancreatitis in people taking the drugs.
Other side effects of Byetta include nausea and other stomach issues. For Januvia side effects also include respiratory infections and headaches. Cypess told Reuters Health both drugs are still protected by patents and can be expensive.
Representatives from Merck and Bristol-Myers Squibb said they - along with drug regulators - actively monitor reports of adverse events in users of their drugs, and have not found evidence showing the drugs cause pancreatitis.