A retrospective chart review of ketamine mouthwash use in 8 patients over a period of 4 years was conducted to determine safety and efficacy. Patients in this review received ketamine 20mg/5ml mouthwashes every 4 hours as needed. Seven of the 8 patients were post-hematopoietic stem cell transplant (post-HSCT) patients. Five patients had a documented improvement in mucositis pain and 4 patients experienced an adverse event. Adverse events consisted of mild confusion, nausea, vertigo, and hallucinations; however 2 of the 4 patients had reports of these symptoms prior to beginning ketamine mouthwashes but were still included in the analysis. Patients received an average of 17 doses over an average of 6 days. Reporting of pain scores were variable and difficult to quantify but the authors concluded that ketamine may provide a viable treatment option for mucositis pain. (9)