In the new study, conducted between November 2014 and May 2016, Dr. Robert C. Miller, Professor of Radiation Oncology at Mayo Clinic, and his colleagues studied 275 patients who underwent definitive head and neck radiotherapy and had an oral mucositis pain score of 4 points or greater. The participants were followed up for a maximum of 28 days. The research team found that pain related to oral mucositis was reduced by 11.6 points after using doxepin mouthwash and by 11.7 points after using diphenhydramine-lidocaine-antacid mouthwash, within 4 hours of administration. There was a reduction of 8.7 points for placebo mouthwash. Both experimental rinses were also well-tolerated by patients.