Change of medication

I was diagnosed in 2014, i have been using metformin 500 ever since, my BS was always between 5.9 and 7.9....so last week i got sick with bronchitis, i took all the medication given by the doctor, ...now my doctor said my sugar is too high and changed me to Glucophage 1000 once at night

Any knowledge of this medication, the doctor said its still metformin

Im jst watching the canges so far, i will report evertything..thank u so much