Gabapentin-d₄is intended for use as an internal standard for the quantification of gabapentin by GC- or LC-MS. Gabapentin is a γ-aminobutyric acid (GABA) analogue that acts as an anticonvulsant.^1,2,3It does not bind to GABA receptors, does not influence neural uptake of GABA, and does not inhibit the GABA-metabolizing enzyme, GABA transaminase.^4,5Unlike GABA, which does not pass through the blood-brain barrier, gabapentin penetrates into the central nervous system and binds to the α₂δ-type voltage-gated calcium channels. Formulations containing gabapentin have been used to treat neuropathic pain caused by complex regional pain syndrome type one, cancer, and HIV as well as to control dysesthesias in patients with multiple sclerosis.^1,2,3

1.van de Vusse, A.C., Stonmp-van de Berg, S.G.M., Kessels, A.H.F., et al.Randomised controlled trial of gabapentin in complex regional pain syndrome type I [ISRCTN84121379]BMC Neurol.4(13)(2004) 2.Hahn, K., Arendt, G., Braun, J.S., et al.A placebo-controlled trial of gabapentin for painful HIV-associated sensory neuropathiesJ. Neurol.251(10)1260-1266(2004) 3.Caraceni, A., Zecca, E., Bonezzi, C., et al.Gabapentin for neuropathic cancer pain: A randomized controlled trial from the gabapentin cancer pain study groupJ. Clin. Oncol.22(14)2909-2917(2004) 4.Gee, N.S., Brown, J.P., Dissanayake, V.U.K., et al.The novel anticonvulsant drug, gabapentin (neurontin), binds to the α2δ subunit of a calcium channelJ. Biol. Chem.271(10)5768-5776(1996) 5.Goa, K.L., and Sorkin, E.M.Gabapentin. A review of its pharmacological properties and clinical potential in epilepsyDrugs46(3)409-427(1993)