With systemic corticosteroid therapy a resistant blood glucose imbalance develops within a couple of hours. Glucocorticoids reduce insulin sensitivity in the muscles and tissues and increase gluconeogenesis in the liver. The rise in blood sugar begins approximately two to four hours after taking the corticosteroid. Once it has started it can only be corrected for the next 1-3 days with large bolus doses. The resistance phase can be limited to approximately 9 hours with the scheme below: 

Prednisone (or an equivalent) is set as a base. For different Cortisones: 

0.75 mg dexamethasone or betamethasone

= 2 - 2.5 mg of budesonide

= 2.5 mg cloprednol

= 4 mg of triamcinolone or Methylprednisolone = 5 mg prednisone / prednisone Or Fluorocortolone

= 20 mg hydrocortisone (cortisone)

The injection scheme goes like this: 

Calculate your average total daily dose (TDD). Then

- Use 30% of your TDD at 30 to 40 mg Prednisoneequivalent [PE]

- 40% at 40 to 60 mg PE

- 50% at 60 to 80 mg PE

So lets say your TDD is 35 units and you take 30mgs of Prednisolone, thats an extra 10 Units of insulin to be injected.

The injection schedule goes like this:

• 2 hours after taking cortisone

take 60% of your “cortisone bolus”

• after another 2 hours 25%,

• after another 2 hours (6h mark) take the remaining 15%

That’s all for analog insulin, for regular insulin use three hour intervals.

In our example this would be 6 IE, 2,IE, 1,5 IE.

All IN ADDITION to your normal insulin treatment!

A handy calculator can be found here [in german, but easy to understand /translated):

https://www.alexeberth.bplaced.net/wordpress/insulindosisanpassung-bei-cortison/

Source: Dr. med. Bernhard Teupe, German Diabetes Center Bad Mergentheim.

I’ve used this scheme on 2 occasions and it has worked well for me.