Antihistamines in severe/chronic rhinitis.

Abstract

Oral antihistamines generally represent the first line of treatment (after allergen avoidance) in mild seasonal allergic rhinitis (SAR), and in perennial allergic rhinitis (PAR) where symptoms are intermittent. They are safe, effective and easily administered. First-generation antihistamines experienced problems mainly with sedation and anticholinergic activity. Second-generation antihistamines are safer and have largely eliminated these effects, although a very small number of patients taking terfenadine or astemizole have developed a characteristic ventricular dysrhythmia, 'torsade de pointes'. Ebastine is a potent second-generation H1-blocker that compares well with others in the class. It demonstrates no interaction with alcohol, does not induce sedation and has no clinically relevant effect on QTc interval at up to five times the maximum recommended dose. Ebastine acts rapidly to relieve symptoms of allergic rhinitis (including stuffiness) and has a long duration of action, allowing once-daily dosing. Whilst comparable in efficacy to other second-generation antihistamines at 10 mg, ebastine also has the advantage of flexible dosing. Thus, the lower dose of 10 mg is effective for treatment of mild SAR or PAR, and the dose can be increased to 20 mg once daily for control of patients with severe or chronic symptoms.