Effects of acrivastine, loratadine and cetirizine on histamine-induced wheal and flare responses

It is accepted that studies evaluating histamine-induced wheal and flare re actions in the skin represent a simple and reliable method for demonstratin g pharmacodynamic activity and pharmacokinetics of the H-1-receptor antagon ists, In this study, the effects of single oral doses of acrivastine (8 mg) , loratadine (10 mg) and cetirizine (10 mg) on the histamine-induced wheal and flare reactions were compared in 60 healthy volunteers, The wheal and f lare responses were produced by prick test using 1% histamine solution. Mea surements were performed before the ingestion of antihistamines (baseline v alues) and afterwards at 15, 30, 90, 240, 360 min and 24 h. The values obta ined for each antihistamine were compared with each other and with baseline values. Cetirizine was found to be superior to acrivastine and loratadine for the suppression of wheal and flare responses at 240, 360 min and 24 h ( P < 0.05) and acrivastine was superior to the other two antihistamines for the suppression of flare response at 30 min (P < 0.05). Our results indicat e that a single dose of cetirizine provides a more effective and long actin g suppression on wheal and flare reactions in urticaria when compared to ac rivastine and loratadine.