Hydroxyzine
Hydroxyzine is a first-generation histamine H1-receptor antagonist of the dephenylmethane and piperazine classes that exhibits sedative, anxiolytic, and antiemetic properties. It was first developed in 1955, and has since remained a relatively common treatment for allergic conditions such as pruritus, urticaria, dermatoses, and histamine-mediated pruritus. The active metabolite of hydroxyzine, [cetirizine], is also available as an active ingredient in allergic medications, and is responsible for much of its hydroxyzine's antihistaminic effect. Hydroxyzine is also used for generalized anxiety disorder, tension caused by psychoneurosis, and other conditions with manifestations of anxiety.