Diabetes can lead to nerve damage that causes pain or numbness or tingling in the legs or arms, but a new drug in development looks like a promising treatment.

The drug, epalrestat, delays the progression of diabetic peripheral neuropathy, as the condition is called, and ameliorates its symptoms, according to a report in the journal Diabetes Care.

Epalrestat is an aldose reductase inhibitor, a class of compounds that have been developed to suppress a pathway thought to be involved in diabetic neuropathy, the authors explain, but most of these drugs have shown a weak benefit or unacceptable side effects.

Dr. Nigishi Hotta from Chubu Rosai Hospital, Nagoya, Japan and colleagues studied the efficacy and long-term safety of epalrestat in nearly 600 patients with mild diabetic neuropathy. The subjects were randomly assigned to the drug or to an inactive “placebo” for 3 years.

At follow-up, the epalrestat group showed no significant deterioration in nerve conduction velocity or vibration perception threshold, the team reports, whereas the placebo group experienced significant deterioration in both measures.

After 3 years, the epalrestat group had significantly less numbness of the upper and lower extremities, hypersensitivity, and cramping than did the control group, the researchers note, though there were no significant differences in extremity pain.

There were no severe adverse events, the team reports, and no adverse events were directly attributed to the long-term administration of epalrestat.

The researchers noted that the benefits of long-term treatment with epalrestat are particularly evident in patients with good blood sugar control.

SOURCE: Diabetes Care, July 2006.