Laura,

My son’s endo didn’t want to increase his cortef at the time his levels were high because of the worry over weight gain.  So instead she opted to try the prendisone (equivalent dose to the cortef) because of it’s longer acting ability for his night dose.  His levels came back down and eventually got to a point where his endo felt he might be oversurpressed (in addition to some weight gain) so that was when we switched back to the cortef.  His has been off of prendisone and back on cortef since January of 2006 and things have been good.  Hope that helps. 

Judy