An observation:

Many children will be able to cut back considerably on the circadian rythym dosing.  It will all depend on the severity of their deficiency where CAH is concerned basically.  Going by the bio availability of hydrocortisone abstract we see that the bio availability varies from one child with CAH to the next in this study.  Though it did not exceed 6-8 hours during the day no matter what severity, some children may have complete inability to make cortisol.  Because of that, as the cortisol wears off and  dips below the levels that are expected at that particular time in the day, the pituitary gland will sense this and start to secrete ACTH a great deal sooner.  In children that have some  ability to make cortisol as some children who have been diagnosed much later down the track, the process will take longer.  In other words because when the levels of cortisol dip these children can make some amount of cortisol, it will take longer for the 17 OHP levels to climb to unacceptable levels as this occurs at a slower rate.   

 Activity and sport also would expend cortisol levels faster in a child with severe CAH or SWCAH.  this is why they exhaust more easily and it causes rapid plummeting of cortisol levels  and a therefore a sharper rise in 17 OHP.  Much along the same theory as I have illustrated above.    That is one reason why Laura has been able to cut her daughters doses back to such an extent.  We have not been able to do this with Ashley however.    Infact his growth spurts have been such, that even when we switched from 15mg on conventional dosing per day to 15 mg on the circadian dosing, he grew so much in such a six month period (in contrast with how he was growing before this) that infact we have had to raise his dose and spread it out over six doses.  Something I wanted to do anyway.  In fact if anything he needed four times a day dosing more than a child with much less severe deficiency would have because of the fact that really, he could have been hitting a low much sooner than a late diagnosed child may do.   

When Doctors briefly refer to different children metabolising hydrocortisone differently to others, this is what I feel that they are referring to.

If you switched from conventional dosing to circadian dosing and left the dose the same, being that Jack seems to show signs of over suppression now, he would certainly show it more so then unless you cut back his doses considerably.  Dosing with the circadian rythyms after having an over suppressed child on conventional dosing would cause this. 

You may choose that route, but you "will" have to cut back considerably in doing so.  The mistake we made was switching to such before we actually established what his normal dose would be on conventional dosing.  This left us in uncertainty really because we simply had no idea what his needs were anyway.  As it was I think it was just as well though really.  Had we stayed at 15mg on conventional dosing with Ashley every day, it would certainly not have been enough to cover him if it was only just covering him on ciracadian dosing. 

You have a different problem though Chris.  The current dose is too high obviously and if you switched and did not cut back substantially on the amount per day on the alternative dosing regime, it would result in much worse over suppression than he has currently.

regards

Anne-Marie