Roughly 9 percent of the U.S. population — about 29 million Americans — lives with diabetes, with 8 million among them unaware of their condition [source: ADA]. Diabetes — untreated or poorly managed diabetes, in particular — increases a person's risk of developing heart disease or suffering a stroke and can cause damage to the eyes and kidneys. Diabetes is also the most common cause of peripheral neuropathy in the U.S.; an estimated 60 to 70 percent of diabetics will develop diabetic peripheral neuropathy during their lifetime [source: APMA].
Diabetic peripheral neuropathy is the result of nerve damage caused by chronically high blood sugar. It often begins with tingling, burning and stabbing sensations in fingertips and toes or in the extremities, and progresses into chronic pain, loss of sensation and, in severe instances, amputation.
Duloxetine (Cymbalta) was originally approved to treat depression, but the selective serotonin-noradrenaline reuptake inhibitor (SNRI), it turns out, also effectively reduces the neuropathic pain associated with diabetic peripheral neuropathy. That's chronic pain that affects the patient's mood, sleep and general functioning. The FDA approved duloxetine as a treatment for neuropathic pain in 2005 [source: Chouinard]. Tricyclic antidepressants (TCAs) have proven to be effective in treating neuropathic pain, too, and although they're considered an off-label treatment, these antidepressants are prescribed as first-line approach to treating chronic neuropathic pain.