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