A Placebo Controlled, Randomized, Double Blind Trial of Milnacipran for the Treatment of Idiopathic Neuropathy Pain

A Placebo Controlled, Randomized, Double Blind Trial of Milnacipran for the Treatment of Idiopathic Neuropathy Pain

This is an 11-week randomized, double-blind, placebo-controlled trial of Milnacipran 100 mg/d in patients with idiopathic neuropathic pain. Milnacipran, a dual norepinephrine and serotonin reuptake inhibitor has been a safe and beneficial treatment for patients with fibromyalgia and may be useful to treat patients with painful peripheral neuropathy.

The primary outcome will be assessed by the change in daily averaged weekly 0-10 pain intensity score, from baseline to week 9, by intention to treat analysis. The same analysis will be used on several secondary measures including daily averaged weekly 0-10 pain intensity score the sleep interference scale and the Rand-36 quality of life scale.

Milnacipran helps serotonin and noradrenaline work more effectively on the central nervous system. Serotonin and noradrenaline are molecules made by the brain that affect how your body responds to pain. Milnacipran, a dual norepinephrine and serotonin reuptake inhibitor has been a safe and beneficial treatment for patients with fibromyalgia and may be useful to treat patients with painful peripheral neuropathy. Many clinical trials for neuropathy pain are done in patients with diabetic neuropathy. Idiopathic neuropathy however, is a common cause of neuropathy and accounts for 25% of all neuropathies, and over 50% of small fiber neuropathies. The information in this study will provide information on whether milnacipran also provide benefit as a medication for neuropathic pain.

Inclusion Criteria:

• Male and female patients age 18 to 80 years
• Patients with signs and symptoms of a peripheral neuropathy, with either abnormal nerve conductions or abnormal epidermal nerve fiber density with neuropathic pain.
• Pain will have been present for at least 6 months
• Patients may be on other medications for neuropathic pain (eg, antiepileptic medications, opiates or non steroidal antiinflammatories); however they must be on a stable dose for 4 weeks prior to, with no plan to change during the study
• All patients must have had a normal fasting glucose or B12, thyroid stimulating hormone, and serum protein electrophoresis, since the onset of their symptoms.

Exclusion Criteria:

• Other cause of neuropathy (eg, diabetic neuropathy, toxic neuropathy, HIV neuropathy, celiac neuropathy, inherited neuropathy)
• Unstable angina
• Use of another serotonin and norepinephrine reuptake inhibitors (eg, duloxetine, venlafaxine), tricyclic antidepressants, monoamine oxidase inhibitors (MAOI) or selective serotonin reuptake inhibitors
• Myocardial infarction stroke or life threatening arrhythmia within the last 6 months
• HIV infection
• Hepatic or renal failure
• Pregnancy
• narrow angle glaucoma
• History of epilepsy or a seizure