 Clinicians frequently prescribe an oral H1 antihistamine for allergic rhinitis patients with residual symptoms after taking an intranasal steroid. Surprisingly, the only studies investigating this combination of drugs have failed to show added efficacy of the H1 receptor over the intranasal steroids alone. Adding montelukast, a leukotriene receptor antagonist, to an intranasal steroid has not been studied in a placebo controlled fashion. Wilson and colleagues, in an open study of patients with chronic rhinosinusitis, showed a benefit of adding montelukast. 