Anti-nociceptive effect of gabapentin in mouse models of acute and chronic pain

Purpose: To investigate the anti-nociceptive effect of gabapentin in acute and chronic pain models. Methods: Four mouse models of pain were used in this study. These comprised thermal tests (hot plate and tail immersion tests), and chemical tests (formalin and acetic acid-induced writhing tests). A total of seventy-two (72) albino mice weighing 25 - 40 g (mean weight = 32.5 ± 5.1 g) were used. In each test, the mice were randomly assigned to three sets of 6 mice each: control group, celecoxib group and drug treatment group. Each test was performed at intervals of 30, 60 and 90 min. Results: During the acute phase, there was no significant decrease in foot raising (FR) or licking and biting (L & B) episodes among the groups (p > 0.05). However, these episodes were significantly (p < 0.05) decreased in the second delayed phase, in the celecoxib and drug-treated groups, when compared with normal control group. Gabapentin significantly (p < 0.05) decreased pain response throughout the course of the thermal tests. The number of writhes within 30 min were significantly reduced in celecoxib and gabapentin-treated animals, compared with negative control group (p < 0.05). Gabapentin produced approximately 60 % protection of writhing, similar to that produced by celecoxib, the standard non-steroidal anti-inflammatory drug (NSAID) used (61 %). Conclusion: The results demonstrate that the gabapentin is effective against chronic inflammatory pain in mice and therefore can be potentially developed as an effective anti-inflammatory agent for humans.