The anti-allergic effect of the beta 2-adrenergic agent fenoterol in the nose

Beta-adrenergic agents have a direct relaxing effect on bronchial smooth muscle. In vitro investigations of a number of sensitized preparations have demonstrated an inhibition of the antigen-induced histamine release. Grass pollen allergic patients were pretreated in the laboratory, out of the season, with different dosages of intranasal fenoterol before an allergen challenge and hay-fever patients treated with fenoterol during the season in a clinical trial. The laboratory studies demonstrated a moderate and significant (p less than 0.01) inhibitory effect on the immediate allergen-induced symptoms, suggesting an action on mediator release from mast cells. Fenoterol had only a slight, although significant (p less than 0.05), effect on nasal symptoms in the clinical study. In conclusion, fenoterol seems to have an anti-allergic effect, when applied to the airway mucosa, but the effect on allergic rhinitis does not seem sufficient to justify the introduction of fenoterol as a nasal spray.