Gabapentin enhances the antinociceptive effects of spinal morphine in the rat tail-flick test Journal Article


Authors: Shimoyama, M.; Shimoyama, N.; Inturrisi, C. E.; Elliott, K. J.
Article Title: Gabapentin enhances the antinociceptive effects of spinal morphine in the rat tail-flick test
Abstract: The antinociceptive effects of the combination of spinal morphine and gabapentin were evaluated in the tail-flick test in rats. The intrathecal coadministration of a subantinociceptive dose of morphine at 0.2 μg and gabapentin at 300 μg produced significant antinociception. Pretreatment with spinal gabapentin at 300 μg shifted the dose-response curve of spinal morphine to the left with a decrease in morphine ED50 value from 1.06 μg to 0.34 μg. The antinociceptive effects produced by the combination of a subantinociceptive dose of morphine and gabapentin were reversed by spinal naloxone at 30 μg but were not reversed by spinal bicuculline at 0.3 μg. Furthermore, the concurrent administration of spinal naloxone at 30 μg with the combination of morphine and gabapentin blocked antinociception, while the concurrent administration of spinal bicuculline at 0.3 μg failed to prevent antinociception. These results indicate that the combination of spinal gabapentin and morphine produces an enhancement of antinociception that appears to involve the spinal mu opioid receptors. Furthermore, repeated administration of gabapentin for 3 days did not affect the enhancing effect of gabapentin on the antinociceptive effect of morphine, indicating that tolerance did not develop to gabapentin's ability to enhance morphine antinociception.
Keywords: controlled study; dose response; drug potentiation; nonhuman; animals; animal experiment; animal model; drug synergism; tail; amines; gamma-aminobutyric acid; rat; rats; rats, sprague-dawley; morphine; pain measurement; analgesics; drug combinations; morphine sulfate; mu opiate receptor; tail flick test; injections, spinal; naloxone; gabapentin; nociceptors; cyclohexanecarboxylic acids; latent period; antinociception; movement; narcotic antagonists; bicuculline; male; priority journal; article; acetic acids; intrathecal drug administration; antinociceptive effects; spinal morphine; tail-flick test
Journal Title: Pain
Volume: 72
Issue: 3
ISSN: 0304-3959
Publisher: Elsevier Science BV  
Date Published: 1997-09-01
Start Page: 375
End Page: 382
Language: English
DOI: 10.1016/s0304-3959(97)00065-1
PUBMED: 9313278
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 17 March 2017 -- Source: Scopus
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  1. Kathryn J. Elliot
    21 Elliot