I was recently given 40g of Prednisolone daily for a chest infection. It was a short 4 day course.
My normal fasting BS is about 5.0 .
Day one my BS rose to 10.8 after taking the medication and stayed high all day. BS next morning was 7'0
Day 2 after taking my medication it rose to 12.6 and stayed that high again all day .
Next morning phoned my doctor ( it wasn't him that prescribed me the medication) he was quite alarmed at the rise and told me to stop.
Luckily my fasting BS came back down to 5.3 after 2 days
I'm type 2 BTW and prednisolone is known to raise BS levels
I have split the dose in the past, half morning and half evening and it made no difference.
If one takes prednisolone in evening, it is said to interfere with sleep
I used to find that the steroids had a slight effect morning and lunchtime but really put the glucose levels up teatime and bedtime,
Your diabetes team shold be able to help here. handy that you are on basal bolus.
Best wishes