comparison of loratadine and cetirizine in perennial allergic rhinitis

background: allergic rhinitis (ar) represents a global health problem, affecting 5-50% of the population worldwide and numerous classes of pharmacological agents are available for its treatment. two more popular of these drugs are loratadine and cetirizine. there are few direct comparator studies between these two drugs with inconsistent results. m aterials and methods: a randomized, double-blind study for comparison the therapeutic effects of loratadine and cetirizine was conducted in an otolaryngologic clinic of a general hospital. eighty patients with perennial allergic rhinitis were divided into two equal groups. one group received loratadine 10 mg daily for two weeks and the other group cetirizine 10 mg daily also for two weeks. alterations of the allergic rhinitis symptoms including rhinorrhea, sneezing, nasal itching and nasal obstruction were compared between the two groups. r es ults: severity of all four studied symptoms was reduced by both drugs. although cetirizine had a little more efficacy, their difference was not statistically significant (p>0.05). these two medications were most effective in reducing the sneezing and least effective on the nasal obstruction. c onclusion: loratadine and cetirizine can reduce symptoms of the perennialallergic rhinitis but their difference is not statistically significant.