A Clinical Study in Subjects With Neuropathic Pain From PHN Who Have Had an Inadequate Response to Gabapentin Treatment

Exclusion Criteria

• •Other chronic pain conditions not associated with PHN. However, the subject will not be excluded if:
• •The pain is located at a different region of the body; and
• •The pain intensity is not greater than the pain intensity of the PHN; and
• •The subject can assess PHN pain independently of other pain
• •Is unable to discontinue prohibited medications or non-drug therapies or procedures throughout the duration of the study
• •Hepatic impairment defined as ALT or AST \> 2x upper limit of normal (ULN), or alkaline phosphatase or bilirubin \> 1.5x ULN
• •Chronic hepatitis B or C
• •Impaired renal function defined as creatinine clearance \<60 mL/min or requiring hemodialysis
• •Corrected QT (QTc) interval ≥ 450 msec or QTc interval ≥480 msec for patients with Bundle Branch Block
• •Uncontrolled hypertension at screen (sitting systolic \>160 mmHg and/or sitting diastolic \>90 mmHg)
• •Current diagnosis of active epilepsy or any active seizure disorder requiring chronic therapy with antiepileptic drugs
• •Medical condition or disorder that would interfere with the action, absorption, distribution, metabolism, or excretion of GEn, or, in the investigator's judgment
• •Is considered to be clinically significant and may pose a safety concern, or,
• •Could interfere with the accurate assessment of safety or efficacy, or,
• •Could potentially affect a subject's safety or study outcome
• •Current or chronic history of liver disease (including acute viral hepatitis), or known hepatic or biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones).
• •Meets criteria defined by the DSM-IV-TR for a major depressive episode or for active significant psychiatric disorders within last year
• •Depression in remission, with or without antidepressant treatment, may participate, unless stable antidepressant regimen is a prohibited medication
• •Antidepressant medication may not be changed or discontinued to meet entry criteria and must be stable for at least three months prior to enrollment
• •History of clinically significant drug or alcohol abuse (DSM-IV-TR) or is unable to refrain from substance abuse throughout the study. Benzodiazepines or atypical benzodiazepines as hypnotic sleep agents permitted.
• •Currently participating in another clinical study in which the subject is, or will be exposed to an investigational or non-investigational drug or device
• •Has participated in a clinical study and was exposed to investigational or non-investigational drug or device:
• •Within preceding month for studies unrelated to PHN, or
• •Within preceding six months for studies related to PHN
• •Treated previously with GEn
• •History of allergic or medically significant adverse reaction to investigational products (including gabapentin) or their excipients, acetaminophen or related compounds