EFFECT OF SYSTEMIC CORTICOID AND ANTIHISTAMINE ALONE OR IN COMBINATION ON ELEMENTS OF THE RESPONSE TO A 2 DOSE NASAL ALLERGEN CHALLENGE

This study examined the effects of low dose systemic corticoid (methyl prednisolone, MP), standard dose antihistamine (terfenadine, TF) or th e combination on response to out-of-season acute allergen challenge. W e feel that a single dose challenge delivered to the nose may represen t real disease imperfectly and in this study used two doses given 1 ho ur apart, hoping to approximate better the circumstances of natural al lergen stimulation. The study used clinical endpoints only: measured n asal airway resistance (NAR), sneeze count, and weight of blown nasal secretions. Subjects showed similar NAR, sneezing, and secretion respo nse to both challenges. With placebo treatment, NAR rose after the fir st allergen provocation and returned to baseline about 30 minutes late r. Antihistamine pretreatment appeared to delay but did not prevent th is rise; low dose corticoid partially inhibited it, and the combinatio n totally ablated the response. All active treatments suppressed sneez ing and secretion better than placebo. Combination corticoid/antihista mine treatment showed no greater effect on sneeze/secretion than did a ntihistamine alone; this differs from our findings in separate studies comparing analogous drug combinations in naturally-acquired ragweed h ayfever.