H2Blockers negating the effects of PPIs

[daw]

While browsing another GERD forum I saw a post discussing the flare ups of GERD and some short term solutions including the use of an H2Blocker/PPI combination. The last sentence is where my question lies:

".....If 20mg of AciPhex helped, but incompletely, you might try increasing the dose to 20mg twice daily. I've found I get much more mileage out of split dosing on all the PPIs I've tried. It won't hurt you for 2 weeks to do this, and your GI doc can advise you further after the endoscopy. You can also try a small dose of ranitidine (Zantac) at bedtime only, say 75 or 150mg. If you take more or take it during the day, however, it negates the effect of the AciPhex, so just do a small bedtime dose if you choose to try this."

I asked how/why the H2Blocker would negate the effect of the PPI. He was told this by his GI doctor and was unable to answer my question but is looking into it. Does anyone know the answer?

[daw]

I found this explanation posted:

PPI's Work much better when as many proton pumps as possible are working to produce acid. This is why you are suppose to take them one half hour before eating in the morning. Because they have a short plasma half-life, it's best to "kick into gear" as many as many pumps as possible, since peak plasma levels occur 1/2 to 2 hours after taking a PPI.

I'm not positive if less pumps are turned on by inhibiting histamine at the h2 receptors (which is what happens with the use of H2 inhibitors such as Zantac, pepcid,etc.), but I do know that acid is needed for the PPI to become the activated form of the drug that combines with the H+/K+ ATPase enzyme, thus inhibiting the pump from making acid.

any comments?