One of the problems with some diabetic medications is that after a time the cease to be effective.
My father had Parkinson's disease. After a while his medicines were no longer effective in fighting his condition. Once a year his doctor put him in the hospital for a few days to conduct a Drug Holiday. They took him off his meds for 72 hours. His shaking increased dramatically during that time. Then he was titrated back on his medicines til the shaking was reduced. This procedure seemed to extend the usefulness of these drugs.
I wonder if this Drug Holiday has been tried on diabetics and if it would be helpful.