Medically reviewed by Daniel More, MD Common side effects of Zyrtec (cetirizine) can include drowsiness, fatigue, dry mouth, ...

Xyzal (levocetirizine) and Zyrtec (cetirizine) are antihistamines taken to relieve allergy symptoms such as sneezing, runny nose, itchy eyes, and hives. Although Xyzal and Zyrtec work similarly ...