Fexofenadine Effective for Seasonal Allergic Rhinitis

Laurie Barclay, MD

September 10, 2003

Sept. 10, 2003 — Fexofenadine and cetirizine are equally effective in seasonal allergic rhinitis (SAR) but fexofenadine is less sedating, according to the results of a randomized, double-blind trial presented on Sept. 10 at the World Allergy Organization Conference in Vancouver, British Columbia, Canada.

"I think it is already well established that fexofenadine has an excellent safety profile," presenter G. Edward Stewart II, MD, from the University of South Florida in Tampa and Allergy & Asthma Care of Florida in Ocala, told Medscape. "This study provides further evidence to support the safety of fexofenadine, and further demonstrates that fexofenadine can provide a high level of efficacy."

In this multicenter study, 495 patients with moderate to severe SAR were randomized to treatment with fexofenadine HCl 180 mg once daily or cetirizine 10 mg once daily for 14 days. The primary efficacy outcome was SAR symptom severity, scored on a five-point scale instantaneously (for the previous one hour) before dosing each day and reflectively (for the previous 12 hours) twice daily.

Reductions from baseline in the 24-hour reflective total symptom score (TSS; average of two daily scores) for fexofenadine and cetirizine were considered to be clinically and statistically equivalent, because confidence intervals (CIs) fell within a 0.7 margin as determined a priori. Reductions were -1.34 ± 0.18 vs. -1.56 ± 0.19 at week 1; -1.84 ± 0.21 vs. -2.09 ± 0.22 at week 2; and -1.56 ± 0.18 vs. -1.78 ± 0.19 overall. Between-treatment difference was -0.22 (95% CI, -0.59 to 0.15).

On a visual analog scale, fexofenadine caused significantly less drowsiness than cetirizine (-2.33 [95% CI, -3.80 to 0.86] vs. 0.37 [95% CI, -1.10 to 1.84]; P = .011). Fexofenadine also showed a trend toward greater improvement in overall motivation to continue treatment (-2.36 [95% CI, -3.83 to 0.90] vs. -0.30 [95% CI, -1.76 to 1.17]; P = .050).

"In patients with moderate to severe SAR, fexofenadine has efficacy equivalent to cetirizine, but with less drowsiness," the authors write.

Aventis supported this study and employs three of its authors. Dr. Stewart is on the speakers' bureau for Aventis, Schering-Plough, Pfizer, UCB, GlaxoSmithKline, Abbott, and AstraZeneca, and he has participated in research projects funded by Aventis, Schering-Plough, Pfizer, GlaxoSmithKline, AstraZeneca, Genentech, Novartis, Boehringer-Ingelheim, Janssen, Abbott, Eli Lilly, G.D. Searle, Miles, Roberts, Merck, and others.

WAOC 2003: Abstract O-15-5. Presented Sept. 10, 2003.

Reviewed by Gary D. Vogin, MD