Exenatide and sitagliptin are hypoglycaemic drugs which act on intestinal hormones that increase the secretion of insulin.

Taking as their starting point the US Food and Drug Administration (FDA) pharmacovigilance database, a research team compared the reports of adverse effects associated with exenatide and sitagliptin between 2004 and 2009 with those relating to other hypoglycaemic drugs.

According to an online article on the website of the specialist medical journal Gastroenterology, 11 times more cases of pancreatitis were reported with exenatide than with other treatments, and 7 times more with sitagliptin. The number of cases of pancreatic cancer was around threefold with both drugs, while thyroid cancers were around 5 times more prevalent with exenatide and not statistically significant with sitagliptin. This worrying evidence converges with an array of arguments, in particular data from animal studies.

Due to the lack of results from comparative morbidity and mortality clinical trials of these recent drugs against the first-line hypoglycaemic drug, metformin, it is difficult to weigh up this worrying evidence.

Given the risks, as a precaution it is better not to use these drugs whose benefits remain unproven apart from a reduction in blood glucose levels, but whose adverse effects are increasingly a cause of concern.

©Prescrire 1 November 2011

"Exenatide and sitagliptin: pancreatitis and pancreatic cancer" Prescrire Int 2011; 20 (121): 267. (pdf, subscribers only)