AAN Issues New Treatment Guideline for Painful Diabetic Neuropathy

Other Pharmacologic Agents
Among other drugs that were analyzed, the panel recommends that the use of capsaicin and isosorbide dinitrate be considered as treatment for PDN (Level B). The authors also recommend that clonidine, pentoxifylline, and mexiletine should probably not be considered as treatment for PDN (Level B). In addition, they note that the Lidoderm patch may be considered for the treatment of PDN (Level C) and that there is insufficient evidence to support or refute the usefulness of vitamins and a-lipoic acid as treatment for PDN (Level U).

“Although capsaicin has been effective in reducing pain in PDN clinical trials, many patients are intolerant of the side effects, mainly burning pain on contact with warm/hot water or in hot weather,” the guideline authors noted.

Nonpharmacologic Treatment Options
Among the nonpharmacologic modalities that were analyzed, the investigators recommend that percutaneous electrical nerve stimulation be considered for treating PDN (Level B). In addition, the authors advised that electromagnetic field treatment, low-intensity laser treatment, and Reiki massage therapy should probably not be considered for the treatment of PDN (Level B). Data were insufficient to support or refute the use of amitriptyline plus electrotherapy for treatment of PDN (Level U).

Clinical Perspective and Future Research
The authors pointed out that the placebo effect varied from 0% to 50% pain reduction in the studies that were reviewed. They also noted that the use of adjuvant analgesic agents, primarily developed for indications other than PDN, is common in this patient group and has been found to lessen pain associated with PDN.

In addition, the study panel pointed out that although PDN is a chronic disease, no data were available regarding the efficacy of the chronic use of any treatment. “It is important to note that the evidence is limited, the degree of effectiveness can be minor, the side effects can be intolerable, the impact on improving physical function is limited, and the cost is high, particularly for novel agents,” the researchers commented.

The workgroup also made recommendations for future research, including the need for a formalized process for rating pain scales for use in all clinical trials. “Clinical trials should be expanded to include effects on quality of life and physical function when evaluating efficacy of new interventions for PDN; the measures should be standardized,” advised Dr. Bril and colleagues. “Future clinical trials should include head-to-head comparisons of different medications and combinations of medications. Because PDN is a chronic disease, trials of longer duration should be done.”