The effect of clemastine and hydroxyzine on cutaneous histamine response in man.

Histamine-induced cutaneous wheals were measured in five healthy volunteers 2, 4, 8 and 24 hours after per os administration of a single dose of clemastine 1 mg and hydroxyzine 25 mg. Clemastine produced a mean wheal suppression of 9%, 18% and 6%, while hydroxyzine produced a mean wheal suppression of 49%, 73%, 82% and 77%. This experiment demonstrates the potent and long-lasting anti-H1 effect of hydroxyzine.