Pain management is essential because, even when the underlying disease process is stable, uncontrolled pain prevents patients from working productively, enjoying recreation, or taking pleasure in their usual roles in the family and society. Chronic pain may have a myriad of causes and perpetuating factors, and therefore can be much more difficult to manage than acute pain, requiring a multidisciplinary approach and customized treatment protocols to meet the specific needs of each patient.
Optimal treatment may involve the use of medications that possess pain-relieving properties, including some antidepressants, anticonvulsants, antiarrhythmics, anesthetics, antiviral agents, and NMDA (N-methyl-D-aspartate) antagonists. NMDA-receptor antagonists, such as dextromethorphan and ketamine, can block pain transmission in dorsal horn spinal neurons, reduce nociception, and decrease tolerance to and the need for opioid analgesics. [Anesth Analg 2001 Mar;92(3):739-44] By combining various agents which utilize different mechanisms to alter the sensation of pain, physicians have found that smaller concentrations of each medication can be used.