Is this a problem you've had since starting on Gliclazide? If so, it could be to do with low BG since it is happening when you are hungry or have missed a meal, because Gliclazide can cause hypos, though your symptoms aren't typical of these. When I'm hypo I don't feel prickly, but I do get shaky and also have an indescribable "crawly" sensation in my arms and upper body, so there is some similarity. I can only suggest you test your BG when you feel like this, then you'll know one way or the other. If it is due to hypo its probably easily dealt with by taking dextrotabs. Better still, try to avoid long periods without food, and don't miss meals!