Effectiveness and safety of fexofenadine, a new nonsedating H1-receptor antagonist, in the treatment of fall allergies.

Fexofenadine HCl is a new, nonsedating H1-receptor antagonist approved for treatment of seasonal allergic rhinitis (SAR). In a double-blind, randomized, placebo-controlled, multicenter trial, 588 patients with fall SAR rated the severity of their symptoms using a scoring system at a screening visit and during a 3-day placebo lead-in period. Patients who did not respond to placebo and met symptom severity criteria were randomized to receive placebo or fexofenadine HCl at 40, 60, or 120 mg bid at 7:00 a.m. and 7:00 p.m. for 14 days. Patients continued to rate the severity of their symptoms immediately before receiving each dose (at trough). A total of 545 patients were included in an intent-to-treat analysis. The change from baseline in the primary efficacy variable (average daily 7:00 p.m. reflective symptom scores) was significantly greater in patients receiving all dosages of fexofenadine HCl than placebo (p < 0.01). All active dosages produced significant decreases (p < 0.05) in secondary end points: 7:00 a.m. reflective symptom scoring; 7:00 a.m. and 7:00 p.m. scoring 1-hour before dose; and bedtime scoring 1-3 hours after the 7:00 p.m. dose. All dosages of fexofenadine HCl were well tolerated, and no effect on QTc was observed. In conclusion, fexofenadine HCl is safe and effective in the treatment of fall SAR, with 60 mg bid being the optimal therapeutic dosage.