Effects of norketamine enantiomers in rodent models of persistent pain.

NMDA-receptor antagonists are potential drugs for chronic pain treatment, in particular for neuropathic pain involving central sensitization processes. Clinical use of available NMDA antagonists, such as ketamine, is limited for this indication due to its side effects (psychotomimetic, sedative, motor). There is a need for novel NMDA-receptor antagonist(s) with better analgesia/toxicity profile(s).