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 ...

British pharmaceutical GSK announced in 2023 that it planned to stop producing its popular Zyrtec-D, an antihistamine and decongestant that contains pseudoephedrine, citing business reasons.

Anti-histamines combined with a decongestant are usually marked with a "D." Claritin-D, Allegra-D, and Zyrtec-D all contain a decongestant called pseudoephedrine, the same active ingredient that ...