Pharmacological Interaction between Gabapentin and Glibenclamide in the Formalin Test in the Diabetic Rat

There is evidence that local peripheral administration of gabapentin produces antinociception through the activation of the ATP-sensitive K+-channel. However, this interaction has not been evaluated systemically, nor in diabetic rat. This work was undertaken to determine whether glibenclamide has any effect on the systemic antinociception induced by gabapentin. Inflammatory pain was induced by injection of formalin in diabetic rats. Reduction of flinching behavior was considered as antinociception. Systemic administration of gabapentin (10-56 mg/kg, i.p.) produced a dose-dependent antinociception in both phases of the formalin test. Also, glibenclamide (1-10 mg/kg, s.c.) blocked the gabapentin-induced antinociception. Given alone glibenclamide did not significantly modify formalin-induced nociception in diabetic rats. Our data suggest that gabapentin is able to reduce formalin-induced nociception in streptozotocin-injected rats. In addition, these data are consistent with gabapentin-mediated activation of ATP-sensitive -K+ channels to produce systemic antinociception in the formalin test in diabetic rats.