Ok ladies so my dr prescribed me Diclegis today for horrible nausea. Can't even get out of bed without throwing up. So I am starting it tonight.  I normally take Zyrtec every night for horrible allergies and I'm wondering if that would be a problem since they are both antihistamines. Anyone ever taken both? I'm just worried if I stop the Zyrtec my allergies will go nuts since I am allergic to damn near everything.