A study has found minimal clinical benefit with doxepin or diphenhydramine-lidocaine-antacid mouthwash for the treatment of oral mucositis-related pain in patients receiving head and neck radiotherapy.
In the phase 3 trial, patients with an oral mucositis pain score of ≥4 points (scale 0-10) were randomised to doxepin mouthwash 25 mg/5 mL water (n=92), diphenhydramine-lidocaine-antacid (n=91) or placebo (n=92). The minimal clinically important difference was a 3.5-point reduction in pain score within four hours of a single dose.
Among 227 participants who completed treatment per protocol, mucositis pain during the first four hours decreased by 11.6 points in the doxepin mouthwash group, by 11.7 points in the diphenhydramine-lidocaine-antacid mouthwash group and by 8.7 points in the placebo group. The between-group difference was 2.9 points (95% CI 0.2-6.0; P=.02) for doxepin mouthwash vs placebo and 3.0 points (95% CI 0.1-5.9; P=.004) for diphenhydramine-lidocaine-antacid mouthwash vs placebo.
The authors concluded that both medicated mouthwashes significantly reduced oral mucositis pain during the first four hours after administration; however, the effect size was less than the minimal clinically important difference.
They say further research is needed to assess longer-term efficacy and safety for both mouthwashes.