Antiallergic activity of H-receptor antagonists assessed by nasal challenge

摘要: Most oral drugs used for the treatment of allergic rhinitis are classified as H1-receptor antagonists, and although they represent major sales throughout world, their mechanism action is still poorly known. In an attempt to understand better in vivo therapeutic effects these drugs, a double-blind, crossover study was carried out. The compared terfenadine loratadine, nonsedative on immediate response upper airways challenge with orchard-grass pollens 14 highly subjects. Increasing numbers pollen grains were insufflated into nostrils, subjects assessed by examining symptoms measuring release histamine prostaglandin D2 nasal secretions. Each drug administered week before challenge. This demonstrated clinical efficacy both comparison that control day, since observed significantly (p = 0.014) greater number grains. Only one patient had significant when treated loratadine versus 10 during day < 0.0023) six 0.01). Prostaglandin occurred higher allergen dose patients drugs. indicates some H1 antagonists also possess antiallergic activities.