This trial was conducted at about 50 sites in Europe and has been clinically completed. Patients had symptoms of painful diabetic neuropathy for 6 months up to 5 years with an optimized diabetic control and at least moderate pain. Patients were not eligible with other chronic pain or any other medical or psychiatric condition, that would have jeopardized or compromised the patient's ability to participate in the trial. After a 2-week run-in phase patients were randomly assigned to one of three treatment arms. All patients who had completed the 6-week titration phase to reach their target dose entered a 12-week maintenance phase. At the end of the maintenance phase, subjects were offered the option of entering the open-label, follow-on trial. The change in pain was measured daily as well as interference of pain with sleep and general activity.

Inclusion Criteria:

• Painful distal diabetic neuropathy

Exclusion Criteria:

• Symptoms of painful distal diabetic neuropathy for less than six months or greater than 5 years