Gabapentin reduces the mechanosensitivity of fine afferent nerve fibres in normal and inflamed rat knee joints

The antiepileptic drug gabapentin has been shown to have an antihyperalgesic effect following central administration. This electrophysiological investigation examined whether peripherally administered gabapentin could modulate the mechanosensitivity of primary afferents innervating normal and kaolin/carrageenan inflamed rat knee joints. Close intraarterial injection of gabapentin (0.01, 1 and 100 mg/kg) dose-dependently reduced afferent firing rate in both normal and acutely inflamed rat knees in response to normal and hyper-rotation of the joint. Thus, in addition to its central mode of action, peripheral administration of gabapentin reduces nociception locally and this may prove to be beneficial in the treatment of various pain syndromes including inflammatory arthritis.