A treatment algorithm for neuropathic pain.
BACKGROUND
Neuropathic pain is a chronic pain syndrome caused by drug-, disease-, or injury-induced damage or destruction of sensory neurons within the dorsal root ganglia of the peripheral nervous system. Characteristic clinical symptoms include the feeling of pins and needles; burning, shooting, and/or stabbing pain with or without throbbing; and numbness. Neuronal hyperexcitability represents the hallmark cellular mechanism involved in the underlying pathophysiology of neuropathic pain. Although the primary goal is to alleviate pain, clinicians recognize that even the most appropriate treatment strategy may be, at best, only able to reduce pain to a more tolerable level.


OBJECTIVE
The purpose of this review is to propose a treatment algorithm for neuropathic pain that health care professionals can logically follow and adapt to the specific needs of each patient. The algorithm is intended to serve as a general guide to assist clinicians in optimizing available therapeutic options.


METHODS
A comprehensive review of the literature using the PubMed, MEDLINE, Cochrane, and Toxnet databases was conducted to design and develop a novel treatment algorithm for neuropathic pain that encompasses agents from several drug classes, including antidepressants, antiepileptic drugs, topical antineuralgic agents, narcotics, and analgesics, as well as various treatment options for refractory cases.


RESULTS
Any of the agents in the first-line drug classes (tricyclic antidepressants, antiepileptic drugs, topical antineuralgics, analgesics) may be used as a starting point in the treatment of neuropathic pain. If a patient does not respond to treatment with at least 3 different agents within a drug class, agents from a second drug class may be tried. When all first-line options have been exhausted, narcotic analgesics or refractory treatment options may provide some benefit. Patients who do not respond to monotherapy with any of the first- or second-line agents may respond to combination therapy or may be candidates for referral to a pain clinic. Because the techniques used at pain clinics tend to be invasive, referrals to these clinics should be reserved for patients who are truly refractory to all forms of pharmacotherapy.


CONCLUSIONS
Neuropathic pain continues to be one of the most difficult pain conditions to treat. With the proposed algorithm, clinicians will have a framework from which to design a pain treatment protocol appropriate for each patient. The algorithm will also help streamline referrals to specialized pain clinics, thereby reducing waiting list times for patients who are truly refractory to traditional pharmacotherapy.
Namaka
Mike
M
University of Manitoba, Health Sciences Centre, Winnipeg, Manitoba R3T 2N2, Canada. namakamp@ms.umanitoba.ca
Gramlich
Colin R
CR
Ruhlen
Dana
D
Melanson
Maria
M
Sutton
Ian
I
Major
Joanne
J
D000465:Algorithms; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000627:therapeutic use*; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D009422:Nervous System Diseases / Q000150:complications*; D009619:Nociceptors / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D016032:Randomized Controlled Trials as Topic; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000927:Anticonvulsants; D000929:Antidepressive Agents, Tricyclic; D017367:Selective Serotonin Reuptake Inhibitors