A Comprehensive Algorithm for Management of Neuropathic Pain

Key points

• The algorithm merges current guidelines and best practice recommendations into a stepwise pathway, from assessment to first- through sixth-line therapy, for chronic non-cancer neuropathic pain in primary care.
• First line: multidisciplinary conservative care and nonopioid medications, namely tricyclic antidepressants, serotonin norepinephrine reuptake inhibitors, gabapentinoids, topicals and transdermal substances.
• Second line: combinations of first-line medications, tramadol and tapentadol; third line: serotonin-specific reuptake inhibitors, anticonvulsants, NMDA antagonists and interventional therapies, with referral to a specialist pain clinic.
• Fourth line: neurostimulation; fifth line: low-dose opioids (no greater than 90 morphine equivalent units); last line: targeted drug delivery for refractory pain.
• A medication trial of three to eight weeks is recommended depending on the drug, with review midway and at the end; conservative therapies used alone should be limited to six to eight weeks.

Overview

This review builds a comprehensive treatment algorithm for chronic non-cancer neuropathic pain for primary care and family physicians. Estimates of neuropathic pain prevalence in the general population range from 1% to 7-8%, and it is much more frequent in diabetes (26%), herpes zoster (19%) and postsurgical pain (10%). Existing guidelines still disagree on the place of opioids, neurostimulation and targeted drug delivery. This overview is based on the abstract, the assessment section and the recommendation statements of the article.

Assessment

Assessment relies on a comprehensive history and examination. Validated questionnaires help identify neuropathic pain: PainDetect (sensitivity 85%, specificity 80%), DN4, where a score of 4 or more makes neuropathic pain likely (83% and 90%), and LANSS (82-91% and 80-94%). Pain intensity can be measured with a numeric rating scale or visual analog scale, and the impact on mood and quality of life with validated scales, with a psychologist assessing catastrophizing, coping and kinesiophobia.

Medications

TCAs should be trialled over four to eight weeks. High-concentration capsaicin (8%) is positioned as third- or fourth-line, or as an alternative in focal neuropathic pain for patients who wish to avoid or cannot tolerate oral treatments. Third-line medications should not be started in primary care; patients who do not tolerate or do not benefit from first- or second-line therapy should be referred to a specialist pain clinic.

Interventions and neurostimulation

Evidence for epidural injections is mixed: the American Pain Society gave a weak recommendation for epidural steroid injection in persistent radiculopathy due to a herniated lumbar disc, and nonparticulate steroids are recommended because of possible catastrophic complications with particulate steroids. The authors do not recommend radiofrequency denervation of the dorsal root ganglion for radiculopathy. NICE and EFNS have recommended neuromodulation for neuropathic pain, and NeuPSIG gave a weak recommendation for spinal cord stimulation in failed back surgery syndrome with radiculopathy and in CRPS.

FAQ

What is the first-line treatment for neuropathic pain in this algorithm?

Multidisciplinary conservative care together with nonopioid medications: tricyclic antidepressants, SNRIs, gabapentinoids, topicals or transdermal substances.

Where do opioids fit?

Low-dose opioids, no greater than 90 morphine equivalent units, are fifth-line, after neurostimulation; targeted drug delivery is the last-line option.

How long should a medication trial last?

Three to eight weeks depending on the drug, with review midway and at the end of the trial; TCAs are trialled over four to eight weeks.

Source

Bates D, Schultheis BC, Hanes MC, et al. A Comprehensive Algorithm for Management of Neuropathic Pain. Pain Med 2019;20(Suppl 1):S2-S12. DOI: 10.1093/pm/pnz075. Open access under CC BY-NC 4.0. Summary prepared by Medpresso from the original publication; it is not a substitute for the full text or for medical advice.