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Clinical nasal decongestant activity with oral antihistamines


Peter Howarth, Respiratory Cell & Molecular Biology Division, University of Medicine, Level D, Centre Block, Southampton General Hospital, Southampton, UK. E-mail:


Allergic rhinitis is an inflammatory condition with increasing prevalence in many developed countries. Although first-generation antihistamines have shown efficacy in the treatment of this disease, they are relatively ineffective for the treatment of nasal blockage. By contrast, studies with newer antihistamines, such as fexofenadine, cetrizine, mizolastine, desloratadine, and azelastine, have shown efficacy in reducing all symptoms of allergic rhinitis, including nasal congestion. This paper focuses on the clinical studies that have been carried out with some of the newer antihistamines and discusses the mechanisms by which they may exert their additional anti-allergic effects.