What exactly causes the weight gain when taking atarax (hydroxyzine)? How does it happen? What can be done to eliminate it the weight gain?

Atarax (hydroxyzine) Since it is a centrally acting antihistamine with sedation properties, it tends to be the slight slowing down of metabolism at nighttime (when metabolism tends to pick up) as well as Atarax (hydroxyzine) does tend to cause some nocturnal eating, which also contributes.