2011
Hyo-Seok Na, Jung-Hee Ryu, and Sang-Hwan Do.
Abstract
Magnesium plays an important role in the prevention of central sensitization and in the attenuation of established pain hypersensitivity, and its main mode of action appears to involve its voltage-gated antagonist action at N-methyl-D-aspartate (NMDA) receptors.
Given the putative function of the NMDA receptor in pain transduction, magnesium has been investigated in various clinical conditions associated with acute or chronic pain. The parenteral administration of magnesium, via an intravenous, intrathecal, or epidural route, may reduce pain, and anaesthetic and analgesic requirements during the intra- and post-operative periods.
The beneficial effects of magnesium treatment have also been demonstrated in patients suffering from neuropathic pain, such as in those with malignancy-related neurologic symptoms, postherpetic neuralgia, diabetic neuropathy, and chemotherapy-induced peripheral neuropathy.
In addition, magnesium therapy has been shown to be effective in alleviating dysmenorrhea, headaches, and acute migraine attacks. Magnesium is playing an evolving role in pain management, but a more thorough understanding of the mechanisms underlying its antinociceptive action and additional clinical studies are required to clarify its role as an analgesic adjuvant.
Introduction
The research interest in NMDA receptors has led to an examination of the interactions between NMDA receptors and the induction and maintenance of central sensitization after nociceptive stimuli (Woolf and Thompson, 1991).
Ketamine and magnesium are representative NMDA receptor antagonists, and in particular, magnesium can regulate calcium access into cells by antagonizing the NMDA receptor (Paoletti and Neyton, 2007), which has encouraged investigations on the use of magnesium as an analgesic adjuvant.
Recent studies have proposed a role for NMDA receptor antagonists in the management of postoperative pain and in other acute and chronic pain conditions. This chapter describes the pharmacologic basis of pain relief by the magnesium ion, and surveys various clinical studies that have examined the antinociceptive effects of magnesium.
Conclusion
The postoperative analgesic adjuvant role of magnesium and its use as an analgesic therapy for the treatment of acute or chronic pain have been suggested for decades. Its antinociceptive effect has been suggested to be due to the blocking of NMDA receptors, and thus, the prevention of central sensitization. More consistent and convincing evidence is required before magnesium can be viewed as an effective adjuvant pain treatment.
