Key takeaways
Zyrtec-D (cetirizine/pseudoephedrine) and Sudafed (pseudoephedrine) are both used to relieve nasal and sinus congestion, but they have some key differences. Zyrtec-D is a combination of an antihistamine (cetirizine) and a decongestant (pseudoephedrine), making it effective for treating both allergy symptoms and congestion. In contrast, Sudafed contains only pseudoephedrine, which is solely a decongestant. Zyrtec-D is typically taken every 12 hours, while Sudafed comes in various formulations that can be taken every 4 to 6 hours or in extended-release forms every 12 or 24 hours. Both medications can cause trouble sleeping if taken too close to bedtime and can raise blood pressure, but Zyrtec-D is more likely to cause daytime drowsiness due to the antihistamine component. Additionally, Zyrtec-D and Sudafed must both be bought at the pharmacy counter and require a photo ID to be purchased. In some states, Zyrtec-D is also considered a controlled substance.
