-it's because of the mechanism by which Gabapentin works; it is an anti-epileptic designed to synergistically increase the action of GABA, an inhibitory neurotransmitter, and therefore block erroneous nerve impulses that issue from damaged nerve, not rom other damaged tissue that nerve signal pain from. In other words, it is an actor on neurological pain from damaged nerves, not on nociceptive pain from other damaged tissue that "normal" nerve are designed to signal from.

Gabapentin was very effective fro me fro my neuropathic small-fiber dmage pain, but it never had any effect on the more "normal" pain of, say, stubbing a toe, or straining a muscle.