Not less than 15 mL of the liquid should be used for each gargle or rinse and repeated three or four times a day, depending on the severity of the treated condition. The liquid should be kept in contact with the inflamed mucosa for at least 30 seconds and then expelled from the mouth. Administration should begin the day prior to commencement of radiation therapy and continue daily during the treatment period as well as after cessation of radiation applications until desired improvement is obtained. In acute sore throat, gargle with 15 mL every 1.5 to 3 hours. The solution should be expelled from the mouth after use.

Benzydamine significantly reduced the basal production of both prostaglandin E2 (PGE2) and 6-keto-PGF1 alpha, the stable breakdown product of prostaglandin I2 (PGI2), in unstimulated human gingival fibroblasts. When the cells were treated simultaneously with benzydamine and the cytokines IL-1beta or TNF-alpha, the agent benzydamine reduced (P < 0.05) the stimulatory effect of IL-1beta and TNF-alpha respectively, on PGE2 and PGI2 production in human gingival fibroblasts. Furthermore, benzydamine reduced (P < 0.05) both the basal level and the cytokine-induced 3H-arachidonic acid release in gingival fibroblasts. The addition of exogenous arachidonic acid to the cells resulted in enhanced PGE2 production, which was reduced (P < 0.05) in the presence of benzydamine.