PURPOSE: In our previous report we described the clinical value of azelastine, an oral antiallergic agent, as an inhibitor of radiation dermatitis. Here we studied the effect of azelastine on normal skin and tumor size after irradiation in a mouse model. METHODS AND MATERIALS: The modifying effects of azelastine on both the degree of radiation dermatitis and antitumoral effect of radiation therapy were investigated in the normal skin as well as in SCC VII tumors of C3H/He mice. The right hind legs, with or without tumors, were irradiated with 20-60 Gy at 0.62 Gy/min. Azelastine was administered via the mouse chow, and acute skin reactions and tumor growth curves were compared between the azelastine and control groups. RESULTS: The acute skin reactions of the azelastine group were significantly less prominent than those of the control group (p < 0.01). At a dose of 40 Gy the dose modification factors were 1.19-1.25. The tumor growth curves of the azelastine and control groups were almost identical, indicating that the treatment response of irradiation was not affected by administration of azelastine. CONCLUSIONS: Application of azelastine reduces the degree of acute radiation dermatitis without affecting the antitumoral effect of radiation therapy.
PURPOSE: In our previous report we described the clinical value of azelastine, an oral antiallergic agent, as an inhibitor of radiation dermatitis. Here we studied the effect of azelastine on normal skin and tumor size after irradiation in a mouse model. METHODS AND MATERIALS: The modifying effects of azelastine on both the degree of radiation dermatitis and antitumoral effect of radiation therapy were investigated in the normal skin as well as in SCC VII tumors of C3H/He mice. The right hind legs, with or without tumors, were irradiated with 20-60 Gy at 0.62 Gy/min. Azelastine was administered via the mouse chow, and acute skin reactions and tumor growth curves were compared between the azelastine and control groups. RESULTS: The acute skin reactions of the azelastine group were significantly less prominent than those of the control group (p < 0.01). At a dose of 40 Gy the dose modification factors were 1.19-1.25. The tumor growth curves of the azelastine and control groups were almost identical, indicating that the treatment response of irradiation was not affected by administration of azelastine. CONCLUSIONS: Application of azelastine reduces the degree of acute radiation dermatitis without affecting the antitumoral effect of radiation therapy.