About desloratadinesecond generation long-acting tricyclic h1 antagonist, antihistamine.mechanism of action of desloratadinesthis second generation antihistamine has a selective peripheral h1-antagonist action.desloratadine competes with free histamine for binding at h1-receptors in the gi tract, uterus, large blood vessels, and bronchial smooth muscle. this inhibit the action of histamine, which subsequently leads to temporary relief of the negative symptoms brought by histaminessindications for desloratadines1. hay fever s2. watery eyes s3. runny nose s4. itching eyes s5. sneezing s6. hives s7. decongestant sstypical dosage for desloratadinessadult (general dose)- 5mg/day schildren (>12yrs)-same as adult