Ketamine Psychedelic and Antinociceptive Effects Are Connected
Anesthesiology February 21, 2022 Erik Olofsen, Jasper Kamp, Thomas K. Henthorn et al. 33 citations
Ketamine produces both pain relief (analgesia) and psychedelic effects, and these two effects are linked, possibly because dissociation generates analgesia. In healthy male volunteers receiving escalating doses of S-ketamine and racemic ketamine, the concentration-effect relationship and the speed of onset and offset were the same for both antinociception and altered external perception. S-ketamine had a potency (C50) of 0.51 nmol/ml and a blood-effect site equilibration half-life of 8.3 minutes. R-ketamine did not contribute to either effect, while S-norketamine had a small antagonistic effect. The authors suggest further studies are needed to explore brain connectivity underlying these effects.