Safety and efficacy of once-daily fexofenadine HCI in the treatment of autumn seasonal allergic rhinitis

Fexofenadine HCl (Allegra, Telfast) is approved in the US for twice-daily d osing in the treatment of seasonal allergic rhinitis (SAR). A once-daily do se (already available in some countries outside the US) can improve patient compliance and health outcomes. This multicenter, placebo-controlled 14-da y US study was conducted to compare the safety and effectiveness of once-da ily fexofenadine HCl with placebo in the treatment of patients with model-a te to severe autumnal SAR symptoms. After a 1-week placebo lead-in, patient s received 120 or 180 mg fexofenadine HCl or placebo at 8 A.M. Patients rec orded SAR symptom severity scores instantaneously (for the I hour before me dication; i.e., trough blood levels), and reflectively (for the previous 12 hours) at 8 A.M. and 8 P.M. The primary efficacy measure was change from b aseline in average instantaneous 8 A.M. total symptom score (TSS, the sum o f individual symptom scores excluding nasal congestion). In 861 intent-to-t reat patients both fexofenadine HCl doses provided significant (p less than or equal to 0.05) improvement in 8 A.M. instantaneous TSS compared with pl acebo. Similarly, both fexofenadine doses were superior to placebo far refl ective TSS assessments (p less than or equal to 0.0012). There were no stat istical differences in efficacy between the two fexofenadine doses, though the 180 mg dose showed a trend toward greater symptom relief Incidence of a dverse events was similar between fexofenadine and placebo groups (30.2% an d 30.0%, respectively), With headache the most frequently reported adverse event (8.9% and 7.5%, respectively). In conclusion, once-daily fexofenadine HCl, 120 or 180 mg, is safe and effective in the treatment of autumnal SAR .