A new topical vasoconstrictor-based strategy for prevention of oral mucositis.

OBJECTIVE: In a new strategy, we sought to determine whether vasoconstriction and transient hypoxia of the mucosa during irradiation would prevent or suppress radiation-induced oral mucositis. STUDY DESIGN: Topical vasoconstrictor was applied once to the oral cavity; 20 minutes later hamsters or mice received 19 to 30 Gy to the mucosa. Oral mucositis was scored using functional assay, gross morphology, and histology of mucosal tissue over the next 12 to 16 days. RESULTS: A single application of phenylephrine (14 mM to 136 mM) 20 minutes before irradiation conferred highly significant (P < .001), dose-dependent suppression of weight loss, oral secretion, and histopathology of mucosa seen in mice treated with 0 mM phenylephrine + 19-Gy irradiation. Epinephrine, norepinephrine, and phenylephrine showed up to 100% radioprotective efficacy at concentrations that reflected their rank-ordered affinities for the alpha1-adrenergic receptor. CONCLUSIONS: Phenylephrine swish-and-spit application before radiotherapy, or multiple applications during chemotherapy, may provide a simple, cost-effective strategy for suppression of oral mucositis in patients undergoing radiotherapy, chemotherapy, or bone marrow transplant.