NMDA receptor antagonists for neuropathic pain

N-methyl-d-aspartate (NMDA) receptor antagonists (e.g. ketamine, dextromethorphan, memantine, and amantadine) may have a role in the management of neuropathic pain. These agents are increasingly used by specialists who manage neuropathic pain e.g. in pain clinics and specialist palliative care clinics.

• Ketamine is generally used as an anaesthetic
  • however at sub-anaesthetic doses it acts as an analgesic by blocking the NMDA receptor in the dorsal horn
  • the NMDA receptor is thought to be activated in clinical states where hyperanalgesia and allodynia are present
  • often ketamine is administered parenterally

Reference:

1. GP (July 5th 2004), 45-6.