All corticosteroids have side effects. Doctors tell us that a physiological replacement dose (which CAH people approximate plus a little more) will not have the same detrimental effects that high dosages have. Trouble is - the doses we have are not always physiological doses.
One major reason being.... that the times we take them are not always the times that our body needs them. We are often off kilter to our bodies endogenous needs. For example late evening doses are definitely not what we produce endogenously. So if we take a dose when we normally wouldn't produce cortisol and our body doesn't really need it then...in my mind that becomes oversuppression. If we don't have it when our body needs it then that is undersuppression for that moment/hour in time. So multiply those moments/hours x 7 days per week x 30 days per month x 12 months per year and for year after year - the problem is evident.
Dex is a much more potent corticosteroid with no mineralocorticoid action as compared to Hydrocortisone and even compared to Pred. The danger in the past has been not to recognise the potency of Dex and prescribe dosages that are too high. A lot of what we have seen with side effects of Dex has been based on these too high doses.
Having said that, in a situation such as your son is facing at this time he may need to have his levels 'stomped' on for awhile to bring them down and it may not even take a huge dose of Dex to do that. It's certainly worthwhile to be aware though of its much higher potency and to follow closely his levels.
I guess the ultimate goal of treatment and management for CAH is to be on the lowest possible dose that brings androgens down into the high end of the normal range or even very slightly above. 17 -ohp does not need to be in the normal person's range and some sources indicate up to 30nmol/L is quite acceptable for normal CAH control as long as androgens are controlled.
This is a huge subject and I could go on but that's probably enough for now.....oh just one thing! If you don't already do it, try to get a copy or write down all lab test results. In doing this over time you will become totally familiar with all the hormones tested and their various parameters - both normal and abnormal.
