Seasonal rhinitis and azelastine: long- or short-term treatment?

Abstract

Azelastine is a topical antihistamine, clinically demonstrated to be effective in allergic rhinitis. We evaluated the clinical efficacy and the antiallergic activity of azelastine nasal spray, administered 0.56 mg per day, 0.28 mg per day, or on demand over a 3-month period during natural allergen exposure, in a double-blind, placebo-controlled fashion. Thirty patients, sensitized to grass or Parietaria pollen, were allocated to three treatment groups: those receiving the standard dosage (0.14 mg/nostril two times a day), half the dosage (0.07 mg/nostril two times a day), or placebo daily for 3 months. All patients were allowed to take additional doses of azelastine when needed. Evaluation parameters were as follows: clinical symptoms recorded on a diary card, number of additional, on-demand azelastine puffs, nasal inflammatory cell count, intercellular adhesion molecule-1 expression on nasal epithelial cells, and pollen count. This study showed the following: (1) the half dose (0.28 mg/day) and the standard dose (0.56 mg/day) were equally effective in reducing clinical symptoms (p = NS), although the standard dosage required fewer additional puffs during times of peak pollen counts (p < 0.05); (2) both dosages were able to reduce the allergic inflammation (p < 0.05 vs placebo); and (3) on-demand use achieved acceptable clinical control but did not significantly reduce allergic inflammation. Continuous treatment was more effective than on-demand use as assessed by both clinical evaluation and antiinflammatory action.