The purpose of this protocol is to determine if an investigational drug is effective in treating nerve malfunction in diabetes.
Inclusion Criteria: * Patients must have type I or type II Diabetes Mellitus. * Have clinically diagnosed positive sensory symptoms such as numbness, lancinating pain, burning pain, aching pain, allodynia and prickling sensation that have been present not greater than 5 years but stable for 6 months. * Has a HbA1C less than or equal to 12%. Patients with HbA1C greater than 9% must be on insulin therapy. * Must be 18 years or older. * Be able to visit the doctor's office approximately 3 times over a maximum of a 6-week period to determine if you can continue in the study. Exclusion Criteria: * History of significant liver problems. * Have poor kidney function. * Drink an excess of alcohol or abuse drugs. * Have recently participated or currently participating in a Medical study in which you receive an experimental drug. * Are a woman and are pregnant or breastfeeding, intend to become pregnant within the next 2 years or a woman not using effective birth control.