The U.S. Food and Drug Administration has approved Eli Lilly's Cymbalta, a balanced and potent serotonin and norepinephrine reuptake inhibitor. Cymbalta is the first and only FDA-approved treatment for pain caused by diabetic peripheral neuropathy.
Cymbalta comes in a capsule and can be taken once a day. The recommended daily dose for Cymbalta is 60 mg. Cymbalta has not been studied in children, and therefore Lilly discourages its use in those under 18. In addition to depression and pain caused by diabetic peripheral neuropathy, duloxetine hydrochloride, the active ingredient in Cymbalta, also has been approved in Europe for the treatment of moderate to severe stress urinary incontinence, another condition believed to respond to treatment that affects serotonin and norepinephrine levels.
Diabetic peripheral neuropathy is a problem associated with long standing diabetes or poor glucose control. Peripheral neuropathy is the most common complication of diabetes mellitus, affecting up to 62% of Americans with diabetes. Diabetic peripheral neuropathy can manifest in a variety of ways but is usually characterized by burning, tingling, and numbing sensations beginning in the feet, and later affecting the legs and/or hands.
The safety and effectiveness of Cymbalta were established in two randomized, controlled studies of approximately 1074 patients. Although the mechanism of action is unknown, patients treated with Cymbalta reported a greater decrease in pain compared to placebo. In these trials, 58 percent of patients treated with Cymbalta reported at least a 30 percent sustained reduction in pain. In comparison, 34 percent of patients treated with placebo reported this magnitude of sustained pain reduction.
The most commonly reported side effects were nausea, dry mouth, constipation, and diarrhea. In some cases, patients experienced dizziness and hot flashes.
Prescription Cymbalta is not for everyone. People who are allergic to duloxetine hydrochloride or the other ingredients in Cymbalta should not take it. If you have recently taken a type of antidepressant called a monoamine oxidase inhibitor (MAOI), are taking thioridazine or have uncontrolled narrow-angle glaucoma, you should not take Cymbalta. Talk with your doctor before taking Cymbalta if you have serious liver or kidney problems, glaucoma or consume large quantities of alcohol. Women who are pregnant should talk with their doctor before taking Cymbalta. Nursing while taking Cymbalta is not recommended.
In clinical studies of Cymbalta for pain caused by diabetic neuropathy, the most common side effects were nausea, sleepiness, dizziness, constipation, dry mouth, increased sweating, decreased appetite and fatigue. Most people were not bothered enough by side effects to stop taking Cymbalta. Your doctor may periodically check your blood pressure. Don't stop taking Cymbalta without talking to your doctor.
Cymbalta is also used to treat depression. Patients being treated with antidepressants should be observed closely for clinical worsening of depressive symptoms and suicidality. Patients and their families should watch for these as well as for anxiety, agitation, panic, difficulty sleeping, irritability, hostility, aggressiveness, impulsivity, restlessness, or overexcitement and hyperactivity. Call the doctor if any of these are severe or occur suddenly. Be especially observant when starting any antidepressant therapy and whenever there is a change in dose.