H1ac of 7.9. metformin 500 has been working but endocrinologist wants me on janumet 1000+50 or meformin plus diamacron. which is safer?

Both: Both are safe if used properly but each have different side effects.if only on 500mg metformin why not just increase the metformin if only taking 500 a day.May want to ask him that.The answer may come down on the question of the two of cost.The diamacron is a sulfa drug and has a higher chance of hypoglycemia than the janumet but janumet cost more