Antinociceptive Effects and Interaction Mechanisms of Intrathecal Pentazocine and Neostigmine in Two Different Pain Models in Rats.

All of these results suggest that the combined application of pentazocine and neostigmine is an effective way to relieve pain from formalin and acute incision mechanical allodynia. The synergistic effect between pentazocine and neostigmine is mostly attributed to the kappa-opioid receptor and the cholinergic receptor in the spinal cord.