In March, I shared a case of a woman with diabetes-related peripheral neuropathy to highlight issues of pain management in primary care. To recap: Maria, age 68, had been experiencing burning pain sensations in her feet and ankles for the past 3 years. I decided to prescribe duloxetine, and I asked for and received feedback from readers about my management of this patient.
I appreciate the variety of comments on Maria’s case! It was interesting to read the mix of experiences with treating patients who have peripheral diabetic neuropathy (PDN) as well as the personal experiences overcoming neuropathy. This mix of experiences is a major factor in how we all practice healthcare.
However, some of those who commented felt that I could have offered a couple of other treatments for Maria’s painful condition.
What About Topical Lidocaine?
Readers strongly supported the use of topical lidocaine for Maria. I have found that many patients prefer topical lidocaine for a variety of pain conditions, but its efficacy is largely yet to be established in high-quality clinical trials. A systematic review of randomized, double-blind studies of topical lidocaine for neuropathic pain found 12 studies with a total of only 508 participants. All studies were judged to be at high risk for bias; however, the collective result suggested that topical lidocaine was superior to placebo. No evidence suggests that topical lidocaine was associated with serious adverse events.
A 2019 randomized trial was very supportive of topical lidocaine for neuropathic pain, although in this case it was a specific form of pain: localized neuropathic pain following knee surgery. The study enrolled just 36 patients, but the results were impressive. At 3 months, 95.8% of participants in the lidocaine group experienced at least 30% overall improvement in pain measures, compared with 58.3% of subjects in the placebo group. The rates of at least 50% improvement were 83.3% with topical lidocaine and 50% with placebo.
Overall, it appears that topical lidocaine is effective for neuropathic pain, although more data are necessary overall, and for PDN in particular. Topical lidocaine is rarely used alone; it can be combined with effective oral therapy for PDN.
Or Spinal Cord Stimulation?
Another treatment modality espoused in the comments was spinal cord stimulation. A systematic review supports spinal cord stimulation for PDN specifically; two randomized clinical trials demonstrated improved lower-extremity pain and quality of life associated with spinal cord stimulation, and all 11 observational studies also found a benefit associated with treatment.
Maria is not ready for spinal cord stimulation. This intervention is usually considered after the failure of at least two forms of medical therapy, but it should be kept in mind if her symptoms fail to improve.
Overall, Maria should improve if she and her healthcare provider can agree on the plan of care and demonstrate the patience that the treatment of PDN demands. I am optimistic that Maria will feel better.