Gabapentin was initially approved by the U.S. Food and Drug Administration (FDA) as an anticonvulsant (partial seizure) and is currently extensively used for the treatment of neuropathic pain conditions. Although gabapentin’s mechanism of action is unclear, it does block voltage-gated calcium channels by binding to the α2-δ subunit,23 thereby reducing calcium influx. By blocking calcium influx, gabapentin reduces the release of glutamate and substance P from primary nociceptive afferents, thereby modulating nociceptive transmission.