I just thought I would add a bit to the other responses that most docs probably don’t recommend circadian dosing because they are afraid of compliance issues. (BTW, this is what my son’s dr. said also)

One of the sites Anne-Marie posted (Chronopharmacology of hydrocortisone and 9 alpha-fluorhydrocortisone in the treatment for CAH - Moeller) begins with the statement, "The conventional treatment of CAH with hydrocortisone . . . started at 07:00 h  was ineffective in suppressing the early morning rise in 17-OHP and in turn androgens in about 20% of our patients." From that, I would take it that for about 80% of the patients a conventional dosing schedule works out fine.

My personal (not medical) belief is that some kids are more sensitive to the timing of the doses. In these sensitive kids, some are affected most in terms of height, some in terms of weight.

My son has been fine overall in height, but his weight seems very sensitive to dose changes. Every time we increase he balloons up. For example, this spring we increasd his dose from 9.5mg/m2/day to 12.2mg/m2/day. Three months after the increase he had gained 10 pounds. He is five. There were no changes in his routines, activity levels, or eating habits during that time. (I guess his appetite did increase, but we were pretty good about distracting him and keeping him from increasing food intake. I also made sure his activity level stayed the same or increased)

When he was 0-2 years old and I had complete control over what he ate, we were able to keep his weight in a better zone. It was still high, around 95% when his height was around 50-60%. But it wasn’t so extreme as now.

Now that he is 5 (next week), he has hit the birthday party circuit, he had a preschool teacher with a sweet tooth, goes on a lot of playdates, loves to be with his friends at playlands, etc. Also, I don’t know if this is a Minnesota thing or not, but juice seems to be the beverage of choice here. Although his eating habits at home are still good, it is tougher for me to control his eating outside the home without making the social implications too great. Quite honestly, he packs on fat way more quickly than other kids who eat far more food, and food of much less quality, than him.

I guess in summary, my thought is  .  .  . Circadian dosing may not be the best choice for everyone, but if you have tried other options and you/your child are not thriving like you think they can, why not give it a shot.