Acrivastine--an evaluation of initial and peak activity in human skin.

Twenty-four healthy volunteers were entered into a double-blind, crossover study conducted to establish the time of onset of action and the time to peak activity of acrivastine in suppressing the weal and flare responses to intradermally injected histamine. Volunteers received single doses of 8 mg acrivastine and placebo according to a fully randomized, balanced treatment plan. Acrivastine significantly (P less than 0.001) reduced both the weal and flare responses induced by histamine challenge 30 min after oral dosing, as compared with placebo. Peak inhibition of the flare response was seen at 90 min, and maximal suppression of the weal response occurred at 120 min after administration of acrivastine.