A Treatment Algorithm for Neuropathic Pain: An Update

Objective: The purpose of this review is to provide an update of the neuropathic pain treatment algorithm previously published by Namaka et al. in 2004. This algorithm focuses on the strategic incorporation of the latest pain therapies while providing an update of any recent developments involving medications previously listed in the algorithm.

Data Sources: PubMed, MEDLINE, Cochrane, and Toxnet databases were used to conduct all literature searches on neuropathic pain and targeted treatment strategies. Comprehensive search efforts in the identified databases included studies published between 1980 and 2009. The search term “neuropathic pain” was used along with each of the agents outlined in this review: pregabalin, paroxetine CR, duloxetine, tramadol XL, Tramacet, Sativex, and nabilone.

Study Selection: A total of 90 studies were reviewed and selected based on level 1, 2, and 3 search strategies.

Data Extraction: Level 1 search strategies were initially aimed at evidence-based trials of large sample size (N > 100), with a randomized, double-blind, placebo-controlled design conducted by investigators well versed in the specialty area of interest. A level 2 search was conducted for additional trials that had many, but not all, of the desirable traits of evidence-based trials. In addition, a level 3 search strategy was conducted to compare key findings stated in anecdotal reports of very small (N < 15), poorly designed trials with the results of well-designed, evidence-based trials identified in level 1 and/or level 2 searches.

Data Synthesis: Based on a thorough evaluation of the literature, pregabalin, paroxetine CR, and duloxetine have been placed in the updated algorithm as first-line agents, while tramadol XL, Tramacet, Sativex, and nabilone function primarily as adjunctive agents.

Conclusion: The updated algorithm provides a baseline framework from which clinicians can justify the medication they prescribe.

Abbreviations: BPI = Brief Pain Inventory, CB = Cannabinoid receptor, CBD = Cannabidiol, CR = Controlled release, DN4 = Douleur neuropathique 4 questions, DNIC = Diffuse noxious inhibitory control, DPN = Diabetic peripheral neuropathy, IR = Immediate release, IVR = Interactive voice response, MS = Multiple sclerosis, NE = Norepinephrine, NNT = Number needed to treat, NPS = Neuropathic pain scale, NRS = Numerical rating scale, PHN = Postherpetic neuralgia, PMDD = Premenstrual dysphoric disorder, SF-MPQ = Short-Form McGill Pain Questionnaire, SNRI = Serotonin-norepinephrine reuptake inhibitor, SSRI = Selective serotonin-reuptake inhibitor, TCA = Tricyclic antidepressant, THC = D₉tetrahydrocannabinol, VAS = Visual analog scale.

Consult Pharm 2009;24:885-902.