Comparative efficacy and safety of a once-daily loratadine-pseudoephedrine combination versus its components alone and placebo in the management of seasonal allergic rhinitis

Background: The treatment of symptoms of seasonal allergic rhinitis often requires the use of a decongestant to improve nasal congestion, along with an antihistamine to adequately control other nasal, as well as nonnasal symptoms. Methods: In this double-blind, placebo-controlled, multicenter study, 874 patients with moderate to severe symptoms of seasonal allergic rhinitis were treated with one of the following: SCH 434 QD (a combination of 10 mg of loratadine in the coating and 240 mg of pseudoephedrine sulfate in an extended-release core) once daily, 10 mg of loratadine once daily, 120 mg of pseudoephedrine sulfate every 12 hours, or placebo for 2 weeks. Results: SCH 434 QD was consistently superior to placebo in controlling the symptoms of seasonal allergic rhinitis. Composite symptom scores (total, total nasal, and total nonnasal) were reduced significantly in patients treated with SCH 434 QD as compared with placebo (p < 0.01). When compared with its individual components, reductions in mean symptom scores were consistently greater, numerically, in patients treated with SCH 434 QD than in patients who were treated with either loratadine or pseudoephedrine alone. SCH 434 QD was superior to pseudoephedrine in reducing nonnasal symptoms at all time points (p < 0.01), and superior to loratadine in relieving nasal stuffiness at end point (p < 0.01). In the physicians' evaluation of therapeutic response, the SCH 434 QD group had the greatest number of patients with a good or excellent response at end point (58%). All treatments were generally well tolerated with no serious or unusual adverse events. Insomnia and nervousness, adverse events commonly associated with pseudoephedrine, were noted in a significantly greater number of patients treated with SCH 434 QD or pseudoephedrine (p ≤ 0.04) as compared with those treated with loratadine or placebo. Conclusions: The results of the study demonstrate that SCH 434 QD is more effective than placebo or either of its components alone in the treatment of seasonal allergic rhinitis. (J ALLERGY CLIN IMMUNOL 1995;96:139-47.)