The methods disclosed herein relate to the treatment of histamine H-4—related pruritus, by administering a histamine H-4 receptor inverse agonist that selectively accumulates at the biophases of the disorders, specifically RS-norketotifen or a pharmaceutically acceptable salt thereof. Potentiated antipruritic activity by simultaneous inhibition of histamine H-1 receptors and histamine H-4 receptors are described.
