Researchers find high risk of side effects associated with two new type 2 diabetes medications

Two new drugs used to treat type 2 diabetes may be associated with an increased risk of severe pancreatic and thyroid side effects, according to a new study out of the University of California, Los Angeles.

Researchers reported in the journal Gastroenterology that individuals taking sitagliptin and exenatide were much more likely to develop pancreatitis, pancreatic cancer and thyroid cancer, compared to patients being treated with more traditional medications.

The findings have important implications, as these medications have been growing more common for treating type 2 diabetes. They are extremely effective at controlling blood sugar levels and minimizing the risk of side effects associated with excess glucose, like heart disease, kidney failure and blindness.

After examining a U.S. Food and Drug Administration data base of adverse events for reports related to the two drugs, the team found six times the number of pancreatitis cases related to sitagliptin and exenatide, compared to standard types 2 diabetes medications like insulin or related pharmaceuticals.

Additionally, individuals on these medications were nearly three times more likely to develop pancreatic cancer and 2.7 times more likely to develop thyroid cancer. The high rate of pancreatic cancer may be particularly troubling, since this condition has one of the lowest survival rates of any cancer.

Both sitagliptin and exenatide work to lower blood sugar levels by boosting the activation of a hormone called glucagon-like peptide 1. This compound is known to lower glucose levels. However, in the process, the medications result in a proliferation in the number of ducts used to transmit digestive juices from the pancreas to the gut.

In nearly all cases of cancer, tumors are the result of abnormal cell growth. The fact that sitagliptin and exenatide may spur growth in the pancreas that otherwise would not take place may help explain the increased rates of reported cancer.

The team said further clinical trials need to be conducted to confirm if these medications are the cause of the increased rate of adverse outcomes observed in their study.

The FDA database used in the study is not the ideal source of information because it is open to submissions from just about any medical professional. This may account for some misleading reports. Clinical trials will be the only objective measure of whether or not these medications are the real cause of the observed side effects.

Currently, the American Society of Health-System Pharmacists recognizes that use of sitagliptin may be associated with an increased risk of potentially life-threatening inflammation in the pancreas.

Furthermore, the FDA says it is currently working with the manufacturer of sitagliptin, Merck, which markets the drug as Januvia, to revise warning labels to reflect the growing evidence that the medication may increase the risk of pancreatic side effects.

Healthcare providers are advised to be aware of these risks, though there is no indication the regulatory agency is planning to ban the drug any time in the near future.