Medically reviewed by Lindsay Cook, PharmD Xyzal (levocetirizine) and Zyrtec (cetirizine) are antihistamines taken to relieve ...

However, the key difference between the medications is that, in addition to cetirizine, Zyrtec-D contains an additional ingredient, pseudoephedrine, a nasal decongestant. Cetirizine is an over-the ...

Claritin-D, Allegra-D, and Zyrtec-D all contain a decongestant called pseudoephedrine, the same active ingredient that powers Sudafed. It makes your nose feel less stopped up by narrowing the ...