Duh!!! For at least 5 years we "knew" this!! PPIs and 2C19

In case you missed my further rants about how everyone on Plavix should be tested for 2C19 polymorphisms, often splice site changes, which could hinder the effect of plavix......Now a big fat , No Duh....comes out in the Journal of the American Medical Association.

Let me lay the ground work.........

Plavix, one of the top 3 medications in the world

1. Prescribed to prevent a second heart attack or stroke


2. Prescribed to prevent a clot forming in a coronary artery stent, which one often receives after having a heart attack


3. Given in patients with PAD

It turns out that in order for this medication to work it needs to be converted from Plavix into its active metabolite. This type of medication is called a Pro-Drug. There are others like this, including tamoxifen and codeine.

Well, the enzyme which converts Plavix to its active metabolite is called CYP 2C19. We have known this since 2000. A professor of mine actually published on this back then. We even knew about so called "Plavix resistance" .

We know theorize that Plavix resistance is mainly due to polymorphisms in CYP 2C19. This has been studied since 2000, but only recently came to major light with articles in Lancet, New England Journal of Medicine......and my rants on this Blog and in Lectures at Yale and Affiliated Hospitals....

Now........the fly in the ointment....

Proton Pump Inhibitors(PPIs) like Prilosec and Protonix........Are available over the counter since they are so "benign"......

Well, we have known and studied since 1997 that Prilosec inhibited 2C19's ability to biotransform other medications.

So what about allof the people taking BOTH Plavix and PPIs? Let me guess.... the results are like the data in 1997!!!!! That patients receiving both medications have little Plavix effect and decreased platelet inhibition.

Well, that was shown in 2006 and even some preliminary data in 2004.

So one has to ask, well why haven't we put anything on the label? Why haven't their been huge warnings....even more so....how many people are on Plavix and PPIs? The pharma companies know.......how come they haven't warned people pre-emptively that there "May be a problem"

The FDA always asks how much evidence is enough.....but now with the study just published in JAMA it is painfully clear.....we have missed the boat by requiring TOO MUCH PROOF!!

What does the study say? Those who are on Plavix and Prilosec are 27% more likely to have a recurrent hospitalization or DEATH from acute coronary syndromes than those NOT ON THIS COMBINATION!!!

AND, 2 of 3 people in this study on Plavix......were ALSO on Prilosec!!!!

This study was a retrospective study which does have limitations, but has me asking why do we have 3 years of data on this combo 2003-2006, when we knew that there may have been a problem back in 2000????

Why didn't we do a better post market analysis?

What's even worse......people advocating pharmacogenomics are getting push back from lazy clinicians who are asking for randomized double blinded studies to PROVE this problem.....

But here's what they don't know.....the pharmacology literature is robust with Pgx data, just as it was with PPI 2C19 inhibition data....Too bad doctors don't read pharmacology literature....

Anecdotally, when I was a resident, I pulled all of my patients off PPIs that were on Plavix. What did I do? I did a med reconciliation and became aware of the possible interaction.....In this case it was NO BIG DEAL to put them on H2 blockers instead......

Primum Non Nocere.......not PRIMUM RANDOM DOUBLE BLINDUM.....

This just pisses me off.........9 years to come to clinical light........That is a damn shame, That may also happen with Prasugrel....

The Sherpa Says: Why do we as physicians wait for a large organization to say stop, when we have the education to figure out from the literature when we should have stopped? Or for that matter, when we should have started......the burden of evidence has been overcome here.....Unlike SNP Scans.......