Hydrocortisone VS Prednisone

My husband, diagnosed May 2015 with left frontal lobe GBM, had been using dexamethasone but the side-effect were becoming too severe even though he was down to 2mg per day. His arms easily bruised, bleeding from thinning skin. Does anyone here have any experience with Prednisone or hydrocortisone? Since Dec. 1, my husband started taking prednisone but he seems to get quite irritable even on 7.5mg. A friend, who happens to be a neuro-onc visiting from Scotland, recommended switching over to hydrocortisone.  Our UCLA neuro-onc recommends that we see an endocrinologist, but that's harder to find than you would think. Any conflicts with other off-labels meds or supplements? Thoughts?