 Patients complete the Short-Form McGill Pain Questionnaire at baseline. Patients rate their pain according to questions from the Brief Pain Inventory on a scale of 0 no pain to 10 worst pain imaginable to best describe pain at its worst in the last 24 hours, pain at its least in the last 24 hours, pain on average, and pain right now; record the number and timing of breakthrough analgesic usage, the number of episodes of breakthrough pain, and the total daily dose of methadone hydrochloride; and complete nausea and sleep assessments once daily on days 1-14. 