(I've been meaning to make this post for a while.  With Mike, from VT, wondering why his son is not on Hydrocortisone, I guess the time has come.)

 

Mike, my son is not on Hydrocortisone, either.  He is on Dexamethasone which, like Prednisone, is a long-acting steroid. 

 

There are essentially 3 different steroids that can be used to treat CAH----Hydrocortisone, Prednisone, and Dexamethasone. The basic difference between them is the amount of time they last in the body.  Dex lasts the longest, followed by Prednisone, then HC.  As a result, Dex generally needs to be dosed only 1X/day; Prednisone 2X; and HC 3X or more.   Another difference is that HC has some salt-retaining properties, while the other two do not.  So, if your child is a salt-waster, you will need to be sure that he takes enough florinef to keep his control in check.  (If he is a SW, he will be taking florinef, anyway.)

 

The goal with CAH treatment, especially in the growing years, is to walk that fine line between undersuppression and oversuppression, since both too much---or too little medication---can negatively affect growth.  All three medications have the potential to successfully treat CAH, or to under-suppress or over-suppress the patient.  The key, I feel, is proper management and having a doctor who is familiar with, and knows how to control, the drug. 

 

It's true that HC has been the mainstay of CAH treatment for most of the last 50 years, but there seems to be increasing acceptance in the medical community towards using the longer acting meds.  The main reason, I think, is that compliance is much more difficult with HC.  When you have to dose 3 or more times/day (vs. once or twice), the tendency to forget or to slip up is, obviously, much greater.  In some cases, it appears that doctors have tried to avoid this problem by going to 2X/day with HC---so you will also hear of many parents saying that their children take only 2 HC doses/day.  Apparently, this works for some, but hasn't worked so well for many---recently I've read that there seems to be a movement back towards the 3X/day or more dosing, because of increased incidences of androgen breakthrough.  So, if it appears that the goal is to have some cortisol in the patient for most of the 24-hours in a day---whether it is through frequent dosing with a short-acting med or infrequent dosing with a long-acting med---it would appear that the long acting meds possess an advantage, being that they are much easier to use. 

 

In some ways, this seems so simple that one might wonder why long-acting meds have been avoided for so long.  Again, I feel the answer lies with the issues of control and management.  When you are using a more powerful drug---as with any tool---I think it's obvious that you have to be that much more careful with handling, since any mistake you make becomes amplified.  For treatment of CAH, Dexamethasone---for example---is 80X more potent than HC.  Just imagine having to chop down a tree trunk with a hand or power saw.  There is, admittedly, a much greater danger of personal injury with the latter but, if handled correctly, it can certainly make the job a whole lot easier.  So it is, I think, with long and short acting meds. 

 

There are several reasons why doctors have often been unsuccessful with long-acting meds, in the past, when treating CAH.  Chief among these is the fact that they have grossly underestimated their strength relative to HC.  As I mentioned before, the relative strength of dexamethasone, in comparison to HC---when talking about treatment for CAH---is actually 80X.  If you look at any drug equivalency table, however, you will probably see it noted as either 30:1 or 40:1, a much different number.  Those numbers are applicable when dex is used to treat an infection or inflammation, but incorrect when used for replacement doses.  Unfortunately, most doctors do not seem to recognize this fact.  By using the wrong equivalency with Dexamethasone, you will end up with at least TWICE as much medication, as the child actually needs.  Is it ANY WONDER then, that these children end up oversuppressed, overweight, and with stunted growth---what many doctors have often complained of, in the past???!!!!!

 

Other factors that can greatly affect successful use of the more potent drugs are the form of the medication (pill or liquid); its concentration; and the time the drug is taken (morning or night.)  Again, the goal is tight control of the medication; and, again, the more potent the medication, the more carefully one needs to control its use. 

 

So often, when I hear of people reporting bad experiences with a drug like dex, it almost always turns out to be a situation where the drug is incorrectly used, a problem that appears to be fairly rampant.  I would not have believed this to be the case if we didn't have personal experience with this happening---and with Dr. New, the guru of CAH.  And I would even have been willing to believe that our experience was just simple bad luck, if another parent had not come on this mb, in the very recent past, who appeared to be the victim of the same sort of equivalency error that happened to us. 

 

Aside from the equivalency issue, it appears that many doctors who use dex, prescribe the pill.  Again, it is not difficult to see how control is often elusive when you are using such an imprecise tool.  Many times, parents with children on HC complain how difficult it is to break their child's cortef pill into quarters.  Now, imagine how much more chance there is of error when you are trying to do the same thing with a pill that is 80X as strong.  Again, is it any wonder why poor results have often been reported in the past?

 

Our doctor uses Dex exclusively---in babies, young children, and those who are fully grown---and he has been doing so successfully for close to 20 years.  I think he is a GREAT doctor, but even he would probably agree that he is not an alchemist---he just knows how to properly handle his medication of choice.  With Dexamethasone, he will use only a liquid ; of concentration 0.1 mg/ 1 ml ; and he doses it in the morning. (Apparently dex taken at night has the effect of being twice as potent, something that I assume is probably true of other corticosteroids, as well.)

 

My son has been on dexamethasone for most of the two years since he was originally diagnosed by our current endo.  We did briefly switch to a different doctor, and a different medication (Cortef, like everyone else), but elected to switch back.  My son is 8, with a roughly 13 yo. bone age, so our main issue with his CAH is growth.  Since my biggest concern is preserving my child's potential growth, it is hardly likely that I would be defending a medication long commonly associated with stunting growth, if I didn't feel that there was good reason. 

 

It's been a bit of a roller coaster ride for much of the last two years, and most of that has been as a result of treatment decisions made by this other doctor.  I guess the most important lesson I have learned is that---like with everything else---it is not enough to just listen to the "p.r." when dealing with CAH.  So often, I have found that, by digging a little further, the true answer to a question is exactly the opposite of my initial assumption, or what popular opinion or surface appearances would have led me to believe.  I feel that it is important not to just accept "what" you read or hear.   The most interesting revelations seem to come when you also ask the question "Why?"