Background: The efficacy, onset and duration of action and safety of cetirizine 10 mg o.d., fexofenadine 120 mg o.d., and placebo were compared in this investigator-blinded, crossover study involving the use of the Vienna Challenge Chamber.
Methods: 40 volunteers with seasonal allergic rhinitis were exposed to a controlled grass pollen concentration for 6 h on 2 consecutive days. Subjective symptoms and objective measurements were recorded during the allergen exposure periods.
Results: Both active medications were significantly more effective than placebo and had a comparable onset of action in alleviating the symptoms of seasonal allergic rhinitis. The efficacy of both active drugs was comparable for the first 4 h after administration of the drugs on day 1 and day 2. However from 22 to 24 h after the first dose cetirizine was significantly superior to fexofenadine for the major symptom complex score and for sneezing. Concerning the total symptom complex score at day 2 fexofenadine could not reach superiority to placebo. No serious adverse events were reported.
Conclusions: Cetirizine and fexofenadine were significantly better than placebo, also in reducing the symptom of nasal congestion. However cetirizine appears to have a longer duration of action than fexofenadine.
Copyright 2001 S. Karger AG, Basel