Mechanisms of the antinociceptive action of gabapentin.
Gabapentin, a gamma-aminobutyric acid (GABA) analogue anticonvulsant, is also an effective analgesic agent in neuropathic and inflammatory, but not acute, pain systemically and intrathecally. Other clinical indications such as anxiety, bipolar disorder, and hot flashes have also been proposed. Since gabapentin was developed, several hypotheses had been proposed for its action mechanisms. They include selectively activating the heterodimeric GABA(B) receptors consisting of GABA(B1a) and GABA(B2) subunits, selectively enhancing the NMDA current at GABAergic interneurons, or blocking AMPA-receptor-mediated transmission in the spinal cord, binding to the L-alpha-amino acid transporter, activating ATP-sensitive K(+) channels, activating hyperpolarization-activated cation channels, and modulating Ca(2+) current by selectively binding to the specific binding site of [(3)H]gabapentin, the alpha(2)delta subunit of voltage-dependent Ca(2+) channels. Different mechanisms might be involved in different therapeutic actions of gabapentin. In this review, we summarized the recent progress in the findings proposed for the antinociceptive action mechanisms of gabapentin and suggest that the alpha(2)delta subunit of spinal N-type Ca(2+) channels is very likely the analgesic action target of gabapentin.
Cheng
Jen-Kun
JK
Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei.
Chiou
Lih-Chu
LC
D000588:Amines / Q000737:chemistry / Q000494:pharmacology*; D000700:Analgesics / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D020864:Calcium Channels, N-Type / Q000187:drug effects* / Q000378:metabolism; D003509:Cyclohexanecarboxylic Acids / Q000737:chemistry / Q000494:pharmacology*; D000077206:Gabapentin; D006801:Humans; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D018080:Receptors, GABA-B / Q000187:drug effects / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000737:chemistry / Q000494:pharmacology*
D000588:Amines; D000700:Analgesics; D000927:Anticonvulsants; D020864:Calcium Channels, N-Type; D003509:Cyclohexanecarboxylic Acids; D018080:Receptors, GABA-B; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin