Fexofenadine hydrochloride, 180 mg, exhibits equivalent efficacy to cetirizine, 10 mg, with less drowsiness in patients with moderate-to-severe seasonal allergic rhinitis

Background: Previous studies have shown that fexofenadine and cetirizine effectively relieve symptoms of seasonal allergic rhinitis (SAR). Objective: To compare the effects of fexofenadine hydrochloride, 180 mg, and cetirizine, 10 mg, on symptoms, drowsiness, and motivation in patients with moderate-to-severe SAR. Methods: In this 2-week multicenter, double-blind, randomized study, 495 subjects with moderate-to-severe SAR received once-daily fexofenadine hydrochloride, 180 mg, or cetirizine, 10 mg, without regard to food intake. Daily 12-hour reflective (AM, Pm) and instantaneous (AM) individual symptoms and total symptom score (TSS) were evaluated. Drowsiness and motivation were recorded daily using visual analog scale at 7 AM, 10 AM, and 3 Pm. Results: Between-treatment differences in reduction from baseline in AM instantaneous and 24-hour reflective TSS were -0.18 [95% confidence interval (CI), -0.55 to 0.20) and -0.22 (95% CI, -0.59 to 0.15), respectively. Since CIs for reduction in TSS between treatments fell within a 0.7 margin (defined a priori), treatments were considered statistically equivalent. Patients receiving fexofenadine experienced significantly less overall drowsiness vs baseline than those receiving cetirizine [-2.33 (95% CI, -3.80 to 0.86) vs 0.37 (95% CI, 1.10 to 1.84), P =.0110]. There was a trend toward greater improvements in overall motivation with fexofenadine compared with cetirizine [-2.36 (95% CI, -3.83 to 0.90) vs -0.30 (95% CI, - 1.76 to 1.17), P =.0504]. Conclusions: Once-daily fexofenadine hydrochloride, 180 mg, given for 2 weeks caused statistically and clinically equivalent improvement in symptoms and significantly less drowsiness va baseline, compared with cetirizine, 10 mg, in patients with moderate-to-severe SAR.