Promising Choice for Diabetic Neuropathy Pain

RESEARCH IDENTIFIES PROMISING CHOICE FOR MANAGING PAIN OF DIABETIC NEUROPATHY UW researcher says drug is first effective option in more than a decade

MADISON -- A new study led by researchers from the University of Wisconsin Medical School has found that a medication now used for controlling seizures is also effective against the pain of diabetic neuropathy -- and produces fewer and less serious side effects than currently available treatments.

Gabapentin, an anti-convulsant available in the U.S. for four years, not only significantly reduced pain from chronic neuropathy (due to damaged nerves) but also reduced sleep disturbances, improved mood and enhanced patientsπ quality of life.

The findings are reported in the Dec. 3 edition of the Journal of the American Medical Association.

Neuropathy, or nerve damage, is the most common complication of diabetes: up to 45 percent of diabetic patients develop neuropathy in the course of the disease. While some patients report a numbness or tingling sensation, others experience neuropathic pain as a very distressing ≥pins and needles≤ sensation or one similar to receiving a series of electric shocks. Diabetic neuropathy pain most often affects the feet and ankles and to a lesser extent the legs above the knees and the arms. Poor control of blood sugar leads to nerve damage, which in turn may prompt the development of neuropathy.

≥This is the first study in more than 10 years to show thereπs another promising agent for treatment of nerve pain from diabetes,≤ said principal investigator Dr. Miroslav Backonja, associate professor of neurology at University of Wisconsin Medical School and a pain specialist at UW Hospital and Clinics. ≥Gabapentin is a very -more-

page 2 welcome addition to our options for pain control. It is well-tolerated by most patients and stands apart from other drugs in that it doesnπt interfere with other medications.≤ In the study, 165 diabetic patients at 20 medical centers were randomly assigned to either an experimental group, which received gabapentin, or the control group, which received a placebo. All of the patients had a one- to five-year history of pain attributed to diabetic neuropathy. The study was double-blind, meaning neither the patients nor the researchers knew who was taking which agent.

At the end of the eight-week study period, patients turned in daily diaries they had kept to monitor pain and sleep interference and also completed an assessment of their overall well-being. Researchers independently completed their own clinical assessment of change.

Approximately 60 percent of the patients on gabapentin reported at least moderate improvement in their pain, while only 33 percent of placebo patients did. In addition, the medication proved to be well-tolerated; two-thirds of the gabapentin patients were able to take the highest dosage tested in the study. The most common side effects were dizziness and sleepiness, although they typically were of mild or moderate intensity. Backonja and his colleagues also found in the study that patients may get pain relief at dosages less than the maximum (3600 mg) tested, and clinicians are advised to adjust dosages based on their observations of individual patients.

Backonja said gabapentinπs ≥metabolic simplicity≤ -- meaning it does not interact with or compete with other substances -- is important for diabetics, who frequently take several medicines. Gabapentin can be used alone or with other drugs to control pain.

About three percent of Wisconsin residents have diabetes, according to the state Division of Health. The Centers for Disease Control estimates that 15.7 million Americans have the disease; only 10 million have been diagnosed. Its incidence is increasing.

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