Controlled Comparison of the Efficacy and Safety of Cetirizine 10 mg o.d. and Fexofenadine 120 mg o.d. in Reducing Symptoms of Seasonal Allergic Rhinitis

Abstract

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.

Allergic Rhinitis and its Impact on Asthma (ARIA) 2008*

“…Pollen exposure in the environmental exposure unit is an effective, reproducible, safe and suitable method for single-center clinical studies (1320)(1321)(1322)(1323). These exposure units are mostly used to assess the efficacy of antiallergic treatments.…”

The Clinical Use of Cetirizine in the Treatment of Allergic Rhinitis

“…Several well-controlled trials have compared the efficacy of cetirizine with placebo and/or other H 1 antihistamines in adults and children with SAR and PAR/PER [43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80]. The majority of these trials have been conducted as double-blind, randomized, placebo-controlled, parallel-group studies in large groups of patients recruited from a single or multiple centres.…”

“…severe/very severe symptoms). Although most of the studies in SAR patients were generally conducted during specified pollen seasons, some studies investigated the effects of therapy in specially built exposure chambers, which allowed investigation of controlled pollen allergen-induced symptoms in the absence of naturally occurring confounding factors such as variable airborne pollen levels, multiple pollen/non-pollen airborne allergens, air pollutants, and variable geographic/climatic conditions [59,60,61,62,63,64]. …”

“…The efficacy of therapeutic doses of cetirizine has been compared in several studies with that of therapeutic doses of other commonly employed and newer preparations of SGAHs in adolescent/adult patients with SAR [55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72] and adolescent/adult and paediatric patients with PAR/PER [73,74,75,76,77,78,79,80]. The majority of these studies have compared the effects of the various antihistamines directly with that of cetirizine and/or placebo on the reduction of symptom severity scores, using different composites of the individual symptom scores as the main efficacy measure.…”

“…Similarly, comparison between single doses of fexofenadine 180 mg and cetirizine 10 mg in SAR patients ‘primed' with pollen in the environment exposure unit have demonstrated cetirizine 10 mg to be significantly superior to fexofenadine 180 mg and placebo in reducing the symptoms of AR over the entire course of study period following administration of the initial dose [62,63]. In contrast, other studies have not been able to demonstrate any significant differences between fexofenadine 120 mg or fexofenadine 180 mg and cetirizine 10 mg in the treatment of AR symptoms in patients exposed to pollen under experimental [64] or natural seasonal [65,66] conditions, although all active treatments were significantly more effective than placebo. Similarly, several studies investigating the less commonly employed or newer preparations of H 1 antihistamines in the treatment of symptoms in sensitized and symptomatic SAR patients during the grass/tree pollen season have not been able to show significant differences between therapeutic doses of cetirizine and mizolastine [67], emedastine [68], rupatadine [69], bilastine [70] or azelastine [71], although all active treatments were significantly effective in reducing specific total symptom severity scores from baseline or when compared with placebo.…”