There has been a bit of bad press for Januvia (Sitagliptin).
However, if you can tolerate the drug, and don't get the side effects, then it is a useful T2 diabetic drug.
It gives the patient, who has a slow or weak insulin response a boost of insulin to lower the spike derived from a meal, especially if it contains too much carbs and sugars.
Diamiacron (Glicizide) is a commonly used drug for getting good control of blood sugar levels, and I have heard of patients who have had both drugs prescribed because of the patients high blood sugar levels.
If you are worried about this treatment, speak to your GP, especially if you are getting good control or going Keto. You maybe, could get your dosage reduced or if your Hba1c and fasting levels are in control come off them altogether.
But do speak to your GP, because, you might not know the reason for the prescription!