Understanding & Overcoming Neuropathic Pain
Chronic pain ranks as a significant public health problem, putting an emotional and financial burden on millions of people. One of the biggest challenges for medical practitioners as a whole is when pain is neuropathic in origin. In neuropathic pain, the nerve fibers themselves become damaged, dysfunctional, or injured. Neuropathic pain proves resistant to many forms of treatment, leaving people frustrated, limited in daily life, and not knowing where to turn. Much of the alterations in neuropathic pain occur at the spinal cord. Ongoing pain over stimulates NMDA receptors in the spine, causing them to overreact to future sensory input. Mild pain is felt as more severe pain, and it causes very real physiological reactions. Even normal sensations such as touch can become painful due to central sensitization.
First-line treatments for chronic pain include antidepressants, anti-epileptics, and opioids, but, in the general medical community, these treatments do not create adequate pain relief in 60% of patients or more.1,2 When first-line approaches are not working, there is definitely another option. A drug called ketamine directly blunts the spine’s NMDA receptors involved in neuropathic pain.3-5 Current medical research is exploring treatment protocols to deliver small ketamine infusions that can provide lasting relief for intractable pain.6-9 In one study, researchers treated complex regional pain syndrome with IV ketamine. Complex regional pain syndrome is a very difficult to treat source of chronic neuropathic pain. One hundred percent of study participants experienced complete pain relief from one to three IV ketamine treatments.6
Because of the way ketamine works, patients with many types of pain can expect dramatic pain relief that standard treatments were unable to achieve. IV ketamine can be an option for complex regional pain syndrome, fibromyalgia, post-herpetic neuralgia, peripheral nerve injury, chronic migraine, chemo-induced pain, phantom limb pain, spinal cord injury, and a long list of other pain etiologies that have neuropathic components. One of the reasons that IV ketamine is not a first-line approach for pain management is that treatment is often time-consuming and labor-intensive. To achieve lasting pain relief, patients must visit the office of a specialized practitioner (such as The Taub Group) for several infusions initially. Subsequent maintenance treatments may be continued every 30 to 90 days, and potentially on an as-needed basis.
PDF’s and References
- Dworkin R, O’Connor A, Audette J, et al. Recommendations for the pharmacological management of neuropathic pain: an overview and literature update. Mayo Clin Proc. 2010; 85: S3–14.
- Finnerup N, Otto M, McQuay H, et al. Algorithm for neuropathic pain treatment: an evidence based proposal. Pain. 2005; 118: 289–305.
- Eide K, Stubhaug A, Oye I, Breivik H. Continuous subcutaneous administration of the N-methyl-D-aspartic acid (NMDA) receptor antagonist ketamine in the treatment of post-herpetic neuralgia. Pain. 1995 May. 61(2):221-8.
- Pockett S. Spinal cord synaptic plasticity and chronic pain. Anesth Analg. 1995 Jan. 80(1):173-9.
- Carpenter K, Dickenson A. NMDA receptors and pain–hopes for novel analgesics. Reg Anesth Pain Med. 1999 Nov-Dec. 24(6):506-8.
- Correll G, Maleki J, Gracely E, et al. Subanesthetic ketamine infusion therapy: a retrospective analysis of a novel therapeutic approach to complex regional pain syndrome. Pain Med. 2004 Sep. 5(3):263-75.
- Kiefer RT, Rohr P, Ploppa A, et al. Efficacy of ketamine in anesthetic dosage for the treatment of refractory complex regional pain syndrome: an open-label phase II study. Pain Med. 2008 Nov. 9(8):1173-201.
- Sigtermans M, van Hilten J, Bauer M. Ketamine produces effective and long-term pain relief in patients with Complex Regional Pain Syndrome Type 1. Pain. 2009 Oct. 145 (3): 304-11.
- Schwartzman R, Alexander G, Grothusen J. Outpatient intravenous ketamine for the treatment of com-plex regional pain syndrome: a double-blind placebo controlled study. Pain. 2009 Dec 15. 147(1-3):107-15.