My confusion comes from a total mistrust in the information (propaganda) that the pharmacutical companies generate, based on questionable trials. Yes, I have become a baby booming cynic. I don't seem to get a good handle on what we are taking and what it does/doesn't do until I see the patient feedback on the web boards.

I believe only the one form of gabapentin enacarbil was approved, and that was the extended release.
The earlier press releases mentioned others but only Horizant is available in US at this time:

http://www.accessdata.fda.gov/script...ocs/tempai.cfm

There were problems with the FDA approval as I recall, so only this one has made it, and barely...by Glaxo

I guess that's understandable from a safety perspective; wouldn't want to confuse IR enacarbil for regular gabapentin and take 3x as much.

But that doesn't alter that in order to lead to lower dosing requirements, a sustained release pregabalin would also need to be more bioavailable.

There's also a non-enacarbil ER gabapentin - Gralise® but there appears to be much confusion between the two ER formulations. Searching Gralise turns up the Pubmed page on gabapentin, which says nothing about enacarbil, but then refers to the ER form as Horizant. The scary part is that it's enough to confuse the folks who prescribe these things.

Doc

The way enacarbil works, provides the sustained quality.
It is a prodrug and absorbed better than gabapentin, but has to be activated into gabapentin and that takes time--hence the sustained quality. This makes this form of gabapentin a NEW DRUG...hence MORE FDA attention and more approval issues.
more on this here:
http://chembl.blogspot.com/2011/04/n...1-part-xi.html

When I went to FDA today only one enacarbil product was listed=Horizant.

Depomed makes sustained products based on older drugs.
This makes FDA approval much easier, because it is only gabapentin, not a new drug form of it. They only have to provide bioavailability studies, and not efficacy studies like with the enacarbil form.
It is listed on the gabapentin page of the Orange Book. It does not state there ER either--which is confusing. Gralise is the name of it.
The delivery system is explained here:
http://www.rxlist.com/gralise-drug.htm

I agree it is very confusing, and a potential problem at the pharmacy level, most decidedly. Also knowing how doctors are, there is a good potential for wrong prescribing.