Atarax is broadly classified as a tranquilizer. It is not chemically related to the phenothiazines, reserpine, or meprobamate. Hydroxyzine has been shown clinically to be a true rapid-acting ataraxic; it induces calming effects in anxious, tense psychoneurotic adults and also in hyperkinetic children without apparent impairment of mental alertness. It is not a cortical depressant, but its action may be due to suppression of its activity in certain key regions in the subcortical area of the central nervous system. Experimentally, hydroxyzine has been shown to have antispasmodic properties apparently mediated through interference with the mechanism that responds to spasmogenic agents such as serotonin, acetylcholine, and histamine. It also has antihistaminic effects and a possible antiemetic effect.