I went on Janumet 50/1000 twice a day for a few months this time last year. Janumet is a combination drug of Sutaglyptin ( the active part of Januvia) and metformin.
At the time I also read that the class of diabetes drugs called glyptins ( januvia being one of them) were suspected of leading to a higher risk of pancreatic cancer and also heart disease. I do not think this was actually proven hence why they are still prescribed.
On the flip side glyptins are also claimed to actually protect pancreatic beta cells from further diabetic deterioration. A claim which also has not been completely proven.
On balance having managed to get my levels under control I decided, with my doctors consent to go back to a metformin only regime.
But that was a personal choice made partly because I trusted metformin an older drug more than the sitagliptin but also because psychologically being prescribed an additional drug, when I had previously been on metformin alone, felt like a deterioration of my diabetes. But the doctor put me on an increased metformin dosage at first until I proved to him that I could maintain my glycemic control.
Discuss the issue with your doctor and explain your concerns but balance any risks with the benefits to your glycemic control.
Unfortunately, probably no medication is completely innocent and without risk. It 's often a case of what involves the higher risk taking a medication or not taking it.
Pavlos