Morning and evening efficacy evaluation of rupatadine (10 and 20 mg), compared with cetirizine 10 mg in perennial allergic rhinitis: a randomized, double-blind, placebo-controlled trial

BACKGROUND A circadian rhythm of symptoms has been reported in allergic rhinitis (AR). Severity of all major symptoms of AR, including runny nose, sneezing, and nasal congestion, is typically at its peak in the morning. The objective of this study was to explore the efficacy of the antihistamine and platelet activating factor (PAF) antagonist rupatadine in the morning and evening and to evaluate whether rupatadine provides effective symptom relief throughout the 24-hour dosing interval. METHODS A total of 308 patients ≥18 years of age with PAR was randomly assigned to once-daily rupatadine 10 mg, rupatadine 20 mg, or cetirizine 10 mg for 4 weeks in a placebo-controlled, double-blind study. The main outcome was the morning/evening reflective total symptom score (5TSS) over the treatment period. Secondary endpoints included morning/evening reflective nasal total symptom score (4NTSS), individual symptoms, Pdmax1 as percentage of days with daily severest symptom score ≤1, and subject/investigator evaluation of therapeutic response. RESULTS All active groups were significantly more effective than placebo in improving morning and evening evaluations of 5TSS (P < 0.001) and 4NTSS (P < 0.001) at 2 or 4 weeks. At morning evaluation, there was a significant reduction from baseline for 5TSS with rupatadine 10 mg (-36.8%, P < 0.01) and 20 mg (-46.3%, P < 0.01) compared with placebo. Similarly, 4NTSS was reduced significantly more with rupatadine 10 mg (-34%, P < 0.05) and 20 mg (-41%, P < 0.01) compared with placebo. In the cetirizine 10 mg group, the reduction was -32.7% and -32.2% for 5TSS and 4NTSS, respectively, but this reduction was not significant compared with placebo. The percentage reduction was greater at evening than at morning evaluation. 5TSS reduction with rupatadine 10 mg (-40.7%, P < 0.05) and 20 mg (-49.9%, P < 0.01) and cetirizine 10 mg (-40.1%, P < 0.05) was significantly better than with placebo. 4NTSS values for active groups were also significantly improved versus placebo. When individual symptoms were assessed, statistically significant differences for rhinorrhea (P < 0.01), nasal itching (P < 0.01), and sneezing (P < 0.01) were shown in all active groups compared with placebo at morning and evening evaluations. Pdmax1 index was significantly improved for all active groups and the overall efficacy assessed by patients or investigators showed a significant improvement (P < 0.01) versus placebo at 2 and 4 weeks. The incidence of somnolence was significantly greater in all active groups versus placebo. CONCLUSION The sustained 24-hour action of rupatadine 10 mg provides an effective control of morning and evening symptoms in patients with PAR treated for up to 4 weeks.