The aim of this study is to evaluate if memantine or dextromethorphan gave in relay to
ketamine maintains or induces a decrease of pain intensity.
In clinical, after ketamine cure, clinicians have often difficulties to treat patients in
order to maintain analgesia or suggest another treatment if analgesia induced by ketamine was
not effective, which occurs in one quarter of patients. It will be very useful for monitoring
of painful patients evaluate if memantine or dextromethorphan could be an effective
therapeutic alternative in neuropathic pain treatment.