Post-injury repeated administrations of minocycline improve the antinociceptive effect of morphine in chronic constriction injury model of neuropathic pain in rat

► Analgesic effect of morphine decreases during the development of neuropathic pain. ► Post-injury administration of minocycline attenuates CCI-induced neuropathic pain. ► Inhibition of microglial activity could potentiate the analgesic effect of morphine.