I was put on gliclazide to being with, then I discovered low carb and started to get Hypos. At that point, the nurse said I must eat carbs at every meal and between meals. So I stopped taking the gliclazide (maybe I should have taken half tablets) and monitored my BG, as my BG were at reasonable levels, I never took gliclazide again. (I still take Metformin as I don't get the side effects.)
As I am not a doctor I can't advise you what to do, I can only tell you what I did. However, remember it is not possible to get the gliclazide dose right unless you have the amount the same amount of carbs at each meal and each day. Some people do need gliclazide, but lots of other people find that with low carb, they can keep their BG reasonable without it, I don't know of a way of finding out without trying.