- The patient has chronic pain of at least 3 months duration associated with any of the following conditions: cancer, diabetic peripheral neuropathy, postherpetic neuralgia, traumatic injury, complex regional pain syndrome, back pain, neck pain, fibromyalgia (patient has met diagnostic criteria), chronic pancreatitis, or osteoarthritis. Other chronic painful conditions may be evaluated for entry upon discussion with and written approval from the Cephalon medical expert.