Doxepin Hydrochloride in Treating Oral Mucositis Pain in Patients With Head and Neck Cancer Undergoing Radiation Therapy With or Without Chemotherapy

OUTLINE: This is a multicenter study. Patients are stratified according to gender, concurrent radiosensitizing chemotherapy (yes vs no), and age (\< 60 years vs ≥ 60 years). Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive doxepin hydrochloride oral rinse (swish, gargle, and spit)\* over 1 minute on day 1. Patients may crossover to arm II on day 2. * Arm II: Patients receive placebo oral rinse (swish, gargle, and spit)\* over 1 minute on day 1. Patients may crossover to arm I on day 2. The primary and secondary objectives are detailed below. Primary Objective: Determine whether doxepin oral rinse is effective in reducing OM-related pain in patients undergoing RT to the oral cavity, as measured by a patient-reported questionnaire at 5,15, 30, 60, 120 and 240 minutes Secondary Objectives: 1. Assess the adverse event profile of doxepin rinse using a patient-reported questionnaire at 5, 15, 30, 60, 120 and 240 minutes for domains of unpleasant taste, burning or stinging discomfort, and drowsiness. 2. Compare the incidence of using alternative analgesics before 4 hours, between the doxepin oral rinse and placebo arms. 3. Assess patient preference for continued therapy with oral rinse after initial test rinse or after the cross-over phase. NOTE: \* Patients are instructed to avoid taking medications for mucositis pain 60 minutes before and after study medication. After completing study therapy, patients have the option to receive doxepin hydrochloride oral rinse every 4 hours as needed during radiotherapy. Patients complete questionnaires at baseline, and at 5, 15, 30, 60, 120, and 240 minutes after study medication. Patients who choose to continue doxepin hydrochloride oral rinse also complete weekly questionnaires.