Provided is a drug for improving central functions during pain having as active ingredients a narcotic analgesic and a compound having an inhibitory effect on GIRK channel activation current (a GIRK channel inhibiting compound). This drug for improving central functions during pain comprises a GIRK channel inhibiting compound such as tipepidine and a narcotic analgesic such as morphine, wherein the dosis of the GIRK channel inhibiting compound does not by itself exhibit an analgesic effect on pain, nor does the dosis of the narcotic analgesic by itself exhibit an analgesic effect on pain, but this drug improves central functions during pain with few side effects when the doses of the two components are combined.
