Papers of the Week

Chronic pain is a common public health problem and remains an unmet medical need. Currently available analgesics usually have limited efficacy for the treatment of chronic pain, including neuropathic pain and persistent inflammatory pain, or they are accompanied by many adverse side effects. The voltage-gated calcium channel blocker (pregabalin) and potassium channel openers (flupirtine and retigabine) have been widely used for the management of chronic pain, but their effectiveness in combination is unclear. In this research, we evaluated the antinociceptive effects of pregabalin in combination with flupirtine or retigabine in carrageenan-induced inflammatory pain and paclitaxel-induced peripheral neuropathy in mice using the von Frey test. Isobolographic analysis indicated that pregabalin exerted synergistic antinociceptive effects when combined with flupirtine or retigabine in neuropathic and inflammatory pain models. Furthermore, the antinociceptive effects of pregabalin, flupirtine/retigabine, and their combinations were significantly attenuated by the Kv7 channel blocker XE991. The favored dose ratio between pregabalin and flupirtine/retigabine in combinations was also investigated. Finally, we evaluated the motor coordination of their combinations using the rotarod test, and the outcomes underpinned their safety. Collectively, our results support the potential use of pregabalin in combination with flupirtine or retigabine to alleviate chronic pain.