Antiallodynic effect and side effects of Phα1β, a neurotoxin from the spider Phoneutria nigriventer: Comparison with ω-conotoxin MVIIA and morphine

► Phα1β induced longer postoperative pain reduction effect than ω-conotoxin MVIIA or morphine. ► The drugs did not change mean arterial pressure after intrathechal injection. ► Intrathecal administration of ω-conotoxin MVIIA increased the heart rate while Phα1β or morphine had no effect. ► The drugs did not alter neurological performance and the expression of pro or anti-inflammatory cytokines. ► Phα1β has a potential application in the management of postoperative pain with low side effects.