I give Ruby her pred at shot time, so 12 hours apart and not 8. The reason is that the pred will increase her BGs, but it takes some time to do so, and I want the insulin to onset when the effect of the steroid does as well to keep her numbers lower. If you give her the pred every 8 hours, that means the second dose you give her would be late in one of her cycles when the insulin's effect is waning and it can push numbers higher. I call this a pred bump. The pred seems to have less of an effect on her BGs at night, but then again I don't test her in the PM like I do in the day, so it's harder for me to gauge its effects at night. Ruby will usually start the day high and then slide all day long to reach her nadirs well past PMPS sometimes. Just monitor these things, note when you give the pred on her SS to see what it does to her numbers.