Why Do Medical Professionals Low Dose PPIs In Infants

Why Do Medical Professionals Low Dose PPIs In Infants?

Dr. Jeffrey Phillips (Dr. P) replies.

"I have gotten this questions a number of times. Why do physicians prescribe such low doses of PPIs? And why do some of them use H2 blockers instead of PPIs? Here is the issue (I don't want to make this too boring). PPIs (as with most drugs) were developed and initially used in adults. The use of PPIs in infants began soon after Losec (now Prilosec, omeprazole) was released. However, the dosage form was enteric coated granules/pellets, which can be difficult to administer to an infant (many of you have commented over the years and I have witnessed, when I was at The University of Missouri, the little pellets ending up on the infants lips). Again, that is because the PPIs were developed for use in adults. So, I began work on a liquid version of omeprazole while at the University of Missouri. That became Zegerid (the drug I invented), Zegerid does come as a packet of pure powder (which no granules) in a 40mg and 20mg size. Soon after, I did the same thing with lansoprazole (Prevacid).

Anyway after my publications in the medical literature, pharmacists started making up "compounded" suspensions using sodium bicarbonate (just as I had published about). So, the problem is that early on (since I was treating infants with reflux with Dr Marcella Bothwell, ENT i.e. Marci; we measured the half-life of the PPIs (omeprazole and lansoprazole) in the bloodstream of the infants. The half-life tells you how fast a medicine is eliminated from the body (bloodstream). So a half-life of 1.5 hours means that half of the medicine is gone in 1.5 hrs. For ~20 year old and older adults the half-life for most PPIs is about 1.2 to 1.5 hrs (it gets longer the older you get). What we found was that for infants after 4 weeks, the half-life for PPIs was ~0.4 hrs to 0.5hrs. This meant that infants were metabolizing the PPIs about 3 times faster than adults.

Here is some of that data.

At the same time, Dr. Bothwell and I had found that infants did not respond to single daily doses and most only partially responded to twice daily doses, so we were finding that three doses per day were working. Which makes perfect sense because adults typically take a PPI once a day and infants were metabolizing the PPI three times faster; and then we did a study in infants who were only partially responding to their PPI (Dr. Bothwell and I saw infants from all over as word got out that we were having success in the treatment of infant acid reflux). So we did a three center study to see what doses were needed to make symptoms of reflux improve significantly.

Here is that study.

Now fast forward to about 5 years ago. The Pharmaceutical companies all did studies with their PPIs that used a small dose of PPI once a day in infants (it was as if they had each done the same study and just substituted in their own PPI).

The findings: PPIs are no different than placebo at controlling infant acid reflux symptoms (so called infant GERD).

So, you would think that a physician prescribing a PPI for infants (which most still do) would look at these Pharmaceutical company studies with the low dose once a day and say, "Well the small dose once a day does not work, so I will use a larger dose or more times a day" (in fairness some Doctors have done that) - but most just give that same low dose once a day - they prescribe a different type of acid blocker (H2 blocker, such as Zantac).

Zantac is proven to be less effective than PPIs and Zantac (also Pepcid, Tagamet, Axid) is prone to a lack of efficacy after a short period of treatment (this is known as tolerance also called tachyphylaxis). And as we have discussed elsewhere, all medicines have risks but the risk of untreated acid reflux in an infant must also be considered in the risk:benefit equation."

That is the reason why, when you go to your doctor and ask for higher doses, they are reluctant to do so.

Back to PPI Dosing Information Page

Home Page