This is an investigational study. The study drug has been approved for attention-deficit hyperactivity disorder but is investigational as a treatment for cancer related fatigue. The study medication and physical exams will cost you nothing. You will be reimbursed with a fixed amount of money for each scheduled study visit. The payment will be in the form of a gift card for parking expenses and a gift card for gas expenses. The study doctor or study staff can tell you more about when you will be able to receive reimbursement. A total of 50 patients will take part in this study. All will be enrolled at The University of Texas (UT) MD Anderson.