• The primary objective is to determine the reduction in pain score by ketamine mouthwash compared to placebo in head and neck cancer patients with refractory mucositis.
• The secondary objectives are to describe the duration of analgesia and adverse effects associated with ketamine and placebo.

We would like to determine the effectiveness of ketamine mouthwash in providing pain relief to subjects with head and neck cancer suffering from mucositis, a common adverse event of radiation therapy and chemoradiation therapy. Ketamine is a schedule III controlled substance that is generally used to provide anesthesia for short diagnostic and surgical procedures.

Ten subjects will be randomized to two treatment arms. Group A will receive ketamine on Monday, placebo on Wednesday, and ketamine on Friday. Group B will receive placebo on Monday, ketamine on Wednesday, and placebo on Friday. Each subject will swish the study drug or placebo for 2 minutes and spit it out. The use of non-maintenance mucositis medications such as DLM solution will not be allowed during the clinic visit. Subjects may resume non-maintenance mucositis medications at home.

Subjects will be asked to document adverse effects and pain scores at 30, 45, and 60 minutes after study medication. The Richmond Agitation and Sedation Scale (RASS) will be used to determine a subject's sedation level, if necessary. Treatment will last for up to 6 weeks unless an illness or an event occurs that prevents continuation, intolerance to the agent, adverse events, resolution of mucositis pain, or the decision to withdraw from the study.

Inclusion Criteria:

• Subjects diagnosed with head and neck tumors (any histology) receiving ongoing chemoradiation or radiation therapy
• Subjects with mucositis pain refractory to topical management, defined as any self-reported pain score of > 2 in the 24 hours prior to enrollment despite use of topical agents as prescribed
• Age ≥ 18 years
• Ability to understand and willingness to consent and to sign consent form

Exclusion Criteria:

• Active substance abuse at time of registration (alcohol, drugs, non-prescription use of controlled substances)
• Subjects with history of allergic reactions to ketamine
• Persistent oral bleeding: > 15 mL (estimated) per day
• Pregnancy or breast feeding

Adverse events were collected for the duration of the study, which is up to 6 weeks in total. For reporting purposes, if the adverse event occurred immediately after taking Ketamine or Placebo, the event is associated with that respective group.