Doxepin Hydrochloride in Treating Esophageal Pain in Patients With Thoracic Cancer Receiving Radiation Therapy to the Thorax With or Without Chemotherapy

Inclusion Criteria: * Histological confirmation of thoracic malignancies including non-small cell lung cancer (NSCLC), small lung cancer (SCLC), esophageal cancer, hypopharyngeal and laryngeal cancers (for which esophagitis symptoms can be relieved by doxepin swallow), lymphoma, thyroid, thymoma, thymic carcinoma, mesothelioma, sarcoma, and spinal, pulmonary or pleural-based metastases * Planned RT (with or without chemotherapy) to a dose of \>= 20 Gray (Gy) using 1.60 Gy per daily fraction; if radiation is given twice daily, a cumulative planned dose of \>= 15 Gy using at least 1.25 Gy per fraction is required; hypofractionated and stereotactic body radiation therapy regimen are allowed * At least 5 cm of the esophagus must be planned to receive radiotherapy, with a minimum dose of at least 10 Gy * \>= 3 esophageal pain, either at rest or during swallowing, felt to be related to esophagitis for which the patient wants relief, as measured by asking the following question * ?On a scale of 0 to 10 (0 = no pain; 10 = worst pain), what number best describes your chest pain\* (right now) due to your radiation treatment?? * Radiation can cause inflammation in your esophagus which can feel like a chest pain, either at rest or during swallowing * Able to swallow the study medication * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1, or 2 * Negative pregnancy test done =\< 28 days prior to registration, for women of childbearing potential only * Ability to complete questionnaire(s) by themselves or with assistance * Provide informed written consent * Willingness to complete evaluation and questionnaires per protocol at the participating institution for follow-up (during the active monitoring phase of the study) Exclusion Criteria: * Known allergy to doxepin, tricyclic antidepressants, or any known component of the drug formulation * Histologic proof of and getting treatment for esophageal, stomach, spinal cord, thyroid, breast, and head and neck cancers and vertebral metastases * Use of a tricyclic antidepressant or monoamine oxidase inhibitor within the 2 weeks prior to registration * The presence or strong clinical suspicion of a tracheoesophageal fistula, or known esophageal invasion by cancer * Current untreated or unresolved esophageal candidiasis or herpes simplex virus (HSV) infection * Current untreated narrow angle glaucoma * Current untreated urinary retention =\< 6 weeks prior to registration * Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens * Any of the following * Pregnant women * Nursing women * Current use of doxepin or doxepin rinse as a swallow preparation