Efficacy of acrivastine with pseudoephedrine in treatment of allergic rhinitis due to ragweed.

BACKGROUND: Semprex-D capsules contain acrivastine 8 mg (a second generation H1-antagonist) plus pseudoephedrine HCl 60 mg and were developed to satisfy the needs of allergy suffers who prefer combination products designed to provide broader symptom relief. Approval of combination products by the US Food and Drug Administration requires demonstration that each component contributes to the overall effectiveness. OBJECTIVE: The objective of the study was to demonstrate that both acrivastine and pseudoephedrine share in the efficacy of the combination in relieving allergy symptoms in patients sensitive to ragweed pollen. METHODS: This was a double-blind, randomized, placebo-controlled, parallel groups, balanced design, multicenter (13 sites) study. Patients 12 years of age or older with skin test reactivity to ragweed were recruited. Patients who qualified for the study were dispensed either (1) acrivastine + pseudoephedrine, (2) acrivastine, (3) pseudoephedrine, or (4) placebo with instructions to take one capsule 4 times daily and to record allergy symptom scores in a symptom diary 3 times daily for 14 days. Assessments of health, global allergy symptoms, protocol compliance, adverse events, and vital signs were also documented. RESULTS: A total of 702 patients were enrolled in this study. Over the 2-week period, the combination of acrivastine + pseudophedrine was significantly more effective than acrivastine, pseudoephedrine, and placebo for relief of all symptoms (P range .01 to .001); pseudoephedrine for treating symptoms responsive to antihistamines (P = .003); and acrivastine for treating symptoms responsive to nasal decongestants (P < .001). Relatively small increases in adverse experience rates were observed for the combination relative to the placebo. CONCLUSIONS: These findings in a large clinical trial demonstrate that each component of the combination of acrivastine 8 mg plus pseudoephedrine HCl 60 mg contributes to the overall efficacy, thereby supporting the conclusion that the combination is rational, safe, and effective for the treatment of allergic rhinitis.