Therapeutic drugs for neuropathic pain

Neuropathic pain is common and may be resistant to usual doses of analgesic medications. However, an improved understanding of the pathophysiology of neuropathic pain and a growing number of adjuvant medications that are useful for the treatment of neuropathic pain provide renewed hope for clinicians and their patients. It is useful to classify adjuvant analgesic drugs into two broad categories. Membrane stabilizing agents, which include the anticonvulsants, antiarrhythmics and probably corticosteroids, may act by blocking sodium channels on damaged neural membranes. Medications that enhance dorsal horn inhibition, which include the antidepressants and some anticonvulsants, may augment biogenic amine or GABAergic mechanisms in the dorsal horn of the spinal cord. Current evidence regarding efficacy generally does not support the use of one agent over another and selection of a particular agent may depend in part on the expected side effects or experience with a given drug. For maximum analgesic effect, more than one agent may be necessary and to improve therapy and minimize side effects, medications generally should be started at lower doses and titrated slowly to effect. Although labor-intensive, this strategy may improve compliance and optimize patient care.