Efficacy and tolerability of loratadine versus fexofenadine in the treatment of seasonal allergic rhinitis: A double-blind comparison with crossover treatment of nonresponders

Background: Nonsedating antihistamines are well-established treatment for s easonal allergic rhinitis (SAR), but patients do not always respond to the first antihistamine prescribed, Objective., This double-blind, double-dummy, randomized, 2-phase, multicenr er study was designed primarily to compare the therapeutic responses to lor atadine and fexofenadine in patients who failed initial therapy with the ot her drug. Methods: Male and female patients aged 12 to 60 years received loratadine 1 0 mg once daily (n = 331) or fexofenadine 60 mg twice daily (n = 328) for 1 4 days (phase 1); nonresponders tie, those who had <25% reduction in the su m of 5 SAR symptoms rated by the investigator on a 4-point scale) subsequen tly received the alternate medication for 14 days (phase 2). The investigat or's rating of relief (complete, marked, moderate, or slight relief of symp toms or treatment failure) at the end of phase 2 was the primary efficacy m easure: changes in total symptom severity (TSS) assessed by the investigato r (4-point scale) and the patient (11-point visual analog scale) were secon dary measures. Results: Mean decreases in TSS were significantly greater with loratadine t han with fexofenadine for the 659 patients who completed phase 1 (-12.7 vs -10.2, respectively; P = 0.019; patient assessment) and for the 389 patient s who responded to initial therapy (-6.6 vs -6.1, respectively; P = 0.037; investigator assessment). Of the 389 patients who responded to initial ther apy, 61.0% had received loratadine and 57.0% had received fexofenadine. Mor e nonreponders to initial therapy had moderate, marked, or complete relief of symptoms after switching to loratadine than after switching to fexofenad ine (62.4% vs 51.2%, respectively; P = 0.005) and treatment failure in 10.6 % vs 21.7%, respectively (P = 0.011), Conclusion: Overall, loratadine provided significantly better therapeutic r esponse than fexofenadine in patients who failed to respond to initial ther apy with the other drug.