Desloratadine.

Desloratadine is the orally active major metabolite of the nonsedating H1-antihistamine loratadine. The drug had no adverse cardiovascular effects in various animal models or when administered at 9 times the recommended adult dosage for 10 days in volunteers. Therapeutic dosages had no effects on wakefulness or psychomotor performance in healthy volunteers. No clinically significant interactions have been reported between desloratadine and drugs that inhibit the cytochrome P450 system, nor does the drug potentiate the adverse psychomotor effects of alcohol. Oral desloratadine 5 mg once daily for up to 4 weeks in patients with seasonal allergic rhinitis (SAR) significantly reduced nasal (including congestion) and non-nasal symptoms and improved health-related quality of life compared with placebo. Similar beneficial effects were observed in patients with SAR and coexisting asthma (in whom asthma symptoms and use of beta2-agonists were reduced). Desloratadine 5 mg once daily for 6 weeks significantly improved pruritus and reduced the number of hives compared with placebo in patients with chronic idiopathic urticaria (CIU). Sleep and daytime performance also improved. Desloratadine was well tolerated in clinical trials and had an adverse event profile similar to that of placebo in patients with SAR (with or without asthma) or CIU.