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 dosing in the treatment of seasonal allergic rhinitis (SAR). A once-daily dose (already available in some countries outside the US) can improve patient compliance and health outcomes. This multicenter, placebo-controlled 14-day US study was conducted to compare the safety and effectiveness of once-daily fexofenadine HCl with placebo in the treatment of patients with model-ate to severe autumnal SAR symptoms. After a 1-week placebo lead-in, patients received 120 or 180 mg fexofenadine HCl or placebo at 8 A.M. Patients recorded SAR symptom severity scores instantaneously (for the I hour before medication; 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 baseline in average instantaneous 8 A.M. total symptom score (TSS, the sum of individual symptom scores excluding nasal congestion). In 861 intent-to-treat patients both fexofenadine HCl doses provided significant (p less than or equal to 0.05) improvement in 8 A.M. instantaneous TSS compared with placebo. Similarly, both fexofenadine doses were superior to placebo far reflective TSS assessments (p less than or equal to 0.0012). There were no statistical differences in efficacy between the two fexofenadine doses, though the 180 mg dose showed a trend toward greater symptom relief Incidence of adverse events was similar between fexofenadine and placebo groups (30.2% and 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.