Fentanyl Buccal Tablet or Morphine for Exertional Dyspnea in Cancer Patients

PRIMARY OBJECTIVE: I. To compare the effect of prophylactic fentanyl buccal tablet (FBT), morphine sulfate, and placebo on the increase in the intensity of exertional dyspnea (0-10 point modified Borg scale) measured before versus at the end of a shuttle walk test (SWT). SECONDARY OBJECTIVES: I. To compare the effects of prophylactic FBT, morphine sulfate, and placebo on SWT distance and dyspnea unpleasantness, average daily dyspnea (intensity and unpleasantness, oxygen cost diagram), personalized daily activity (ability to complete activity), personalized dyspnea response, symptom burden (Edmonton Symptom Assessment System \[ESAS\]), quality of life (EuroQol-5 Dimension-5 Level \[EQ-5D-5L\]), and dyspnea severity and functional impairment based on the Patient Reported Outcomes Measurement Information System (PROMIS) dyspnea instruments. II. To explore the effects of prophylactic FBT, morphine sulfate, and placebo on neurocognitive function, addictive potential (Drug Effects Questionnaire), adverse effects (Common Terminology Criteria for Adverse Events \[CTCAE\], Patient-Reported Outcomes version of CTCAE \[PRO-CTCAE\]), and pattern of opioid use. OUTLINE: Patients are randomized to 1 of 3 groups. GROUP I: Patients complete shuttle walk test on days 1, 5, 8, 12, 15, and 19. Patients also receive FBT sublingually daily on days 6-19. GROUP II: Patients complete shuttle walk test on days 1, 5, 8, 12, 15, and 19. Patients also receive morphine orally (PO) daily on days 6-19. GROUP III: Patients complete shuttle walk test on days 1, 5, 8, 12, 15, and 19. Patients also receive placebo (sublingually or PO) daily on days 6-19.