Duloxetine, the active ingredient in the antidepressant Cymbalta, appears to be a safe and effective treatment for pain caused by diabetic peripheral neuropathy, according to a report in the journal Neurology.

In diabetics, peripheral neuropathy occurs when the communication network that transmits information back and forth from the peripheral nervous system to the central nervous system is damaged, resulting in a variety of symptoms including pain, numbness and tingling sensations.

Duloxetine, a selective serotonin and norepinephrine reuptake inhibitor, appears to help patients with neuropathy by blocking pain signals to the brain.

To investigate how duloxetine's effectiveness, Dr. Joachim Wernicke of Eli Lily and Company evaluated 334 non-depressed patients with diabetic peripheral neuropathic pain who were randomly assigned to 60 mg duloxetine once or twice daily, or a placebo.

The researchers found that 53 percent of patients in the twice-daily duloxetine group and 43 percent of patients in the once-daily duloxetine group had a 50 percent reduction in the 24-hour average pain response, compared to 27 percent of patients taking a placebo.

The benefits of duloxetine in reducing the 24-hour average pain severity score also became apparent during the first week of treatment, the researchers said.

All secondary measures of pain, such as night pain and the severity of the worst pain, were significantly improved with duloxetine compared with the placebo. The benefits with once- versus twice-daily duloxetine appeared to be comparable.

The researchers concluded that the trial results support the use of once daily duloxetine for patients with diabetic peripheral neuropathic pain,while twice-daily dosing may provide additional benefits in some patients.