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9 Articles in Volume 14, Issue #6

Migraine Treatment From A to Z

Alternative Medicine in Chronic Migraine 2014: What Clinicians Need to Know

Hormone Abnormalities in Uncontrolled Chronic Pain Patients: Use of Hormone Profiles

Interpreting Negative Urine Drug Test Results

Case Challenge: Chronic Opioid Use Causing Adrenal Insufficiency

Editor's Memo: Toxic Insurance Plans

Guest Editor's Memo: The Forgotten Patients: Those Who Benefit From Opioid Treatment

Ask the Expert: Multiple Benzo Prescriptions

Ask the Expert: Burning Foot Syndrome

July 2014

By Forest Tennant, MD, DrPH, Joseph Shurman, MD, Jennifer P. Schneider, MD, PhD, Kern A. Olson, PhD and Gary W. Jay, MD

Eight months ago, a patient developed diabetic neuropathy. He is now complaining of a severe burning sensation, pain, and numbness in both lower limbs. He currently is taking pregabalin (Lyrica) at 150 mg bid and duloxetine at 60 mg bid. His glucose level is normal (last HbA1C was 7.2%), and all blood reports were normal. What would you recommend for additional treatment?

This is a most timely subject, as I believe burning feet are being seen, at least in my clinic, far more commonly now than in the past. Historically, burning foot syndrome has been associated with diabetes; however, I now see patients with burning feet who have cardiovascular disease, lumbar spine degeneration, viral infections, and who have had surgery.

I attempt to treat this condition with the standard pharmacologic agents of the day, including antidepressants, anti-inflammatories, and neuropathic agents. I will prescribe opioids, if necessary. I have found gabapentin to be the best neuropathic agent. My favorite topical creams and ointments include lidocaine and compounded versions of morphine, diazepam, and carisoprodol. For non-pharmaceutical options, I particularly like the new electromagnetic therapies that can be used at home. Patients now can obtain small, hand-held infrared, radio wave, and laser instruments to complement their pharmacologic treatments and exercises.

Forest Tennant, MD, DrPH

I assume the patient has been seen by a neurologist and endocrinologist, and has excellent control over his diabetes. Instead of pregabalin, I would prescribe gabapentin/enacarbil (Horizant) off label at the highest recommended dose of 600 mg bid. In my experience with the extended-release formula, I can prescribe a lower dose of the medication and get a similar effect as that of high-dose pregabalin but with less side effects (weight gain and edema), which can be a problem for patients with diabetes.¹ I would continue the patient on duloxetine, as prescribed.

Other clinicians might consider dorsal column stimulation. However, a recent article in The Wall Street Journal, raised several issues regarding the treatment.² The FDA database contains 58 unique reports of paralysis associated with spinal cord stimulators (SCS) in 2013, compared with 48 reported incidences of paralysis in 2012. Researchers at Duke University found that nearly 1 patient in every 100 who received a SCS experienced some degree of spinal cord or spinal nerve root damage.³ This study involved records of more than 12,300 SCS patients. In addition, the complication rates can be between 25% and 35%. Therefore, in this particular patient, I would not recommend dorsal column stimulation; however, I am aware that others would.

As a last resort in patients with intractable neuropathic pain, I would prescribe extended- and immediate-release opioids. In some of these cases, patients need high doses of opioids. Historically, we did not prescribe opioids for neuropathic pain, but the evidence for this has changed because of recently published articles supporting their use. Obviously, if opioids are prescribed, urine drug screens should be conducted as opioid risk tools, and, if there is a concern, a baseline consultation with an addictionologist should be conducted. I also recommend psychotherapy support because the risk of suicide in this type of patient is 2 to 3 times higher than the general public.4 Other options include warm water therapy with physical therapy, a trial of transcutaneous electrical nerve stimulation (TENS), topical gels, lidocaine (Lidoderm) patches, and a podiatry consult.

Joseph Shurman, MD

I’d say that the first step is to improve the patient’s diabetes because a hemoglobin A1C level of 7.2 is higher than we would like to see. The patient is taking good medications at reasonable doses for treating neuropathies (pregabalin and duloxetine). I’d also recommend a trial of lidocaine patches on the burning areas. The patches should be cut to cover the burning area; use a maximum of 3 patches and apply for 12 hours per day.

Jennifer Schneider, MD, PhD

Since I am a pain psychologist, I would recommend old-fashioned methods and common sense. I have had some luck with the following procedure: while watching TV, have the patient soak his feet in cool water. If he can tolerate this, have him add a couple of golf balls and massage the bottom of his feet; this should promote circulation.

If you want to consider a surgical option, SCS is an option. Though it is not widely used in the US, it is in Europe, where practitioners appreciate the fact that the treatment can open up the small vessels in the feet and offer symptom relief. I would recommend both modalities.

Kern A. Olson, PhD

The goal of treatment is appropriate pharmacotherapy. First, pregabalin at 150 mg every 12 hours may not be nearly strong enough. As an alternative, you can prescribe gabapentin up to 1,800 mg (600 mg tid) for patients with neuropathies. If this regimen is not effective, you can consider the need to go higher—possibly to 3,600 mg if the patient can tolerate it.

Because pregabalin is an alpha-2-delta calcium channel agonist, the second choice is to add a sodium channel blocker, such as carbamazepine (Tegretol). But check the patient’s blood work first to rule out hematologic abnormalities at baseline. Duloxetine should be continued.

Finally, the last choice (or addition) is an opioid to help “close the delta” between initial and final pain level (pain level after appropriate anticonvulsant medications have be optimized and you have the duloxetine optimized at 60 mg).

Gary W. Jay, MD

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References

Calkins A, Shurman J. Peripheral edema and weight gain in adult patient with painful diabetic peripheral neuropathy receiving gabapentin, enacarbil or pregabalin enrolled in a randomized Phase 2 trial. Presented at American Academy of Neurology, 66th Annual Meeting, Philadelphia, PA: April 26-May 3, 2014.
Walker J. When spine implants cause paralysis, who is to blame? Wall Street Journal. April 16, 2014.
Babu R, Hazzard MA, Huang KT, et al. Outcomes of percutaneous and paddle lead implantation for spinal cord stimulation: a comparative analysis of complications, reoperation rates, and healthcare costs. Neuromodulation. 2013;16(5):418-427.
Horizant package insert. http://www.horizant.com/docs/Horizant_PrescribingInformation.pdf.

Last updated on: May 19, 2015