Compare Zyrtec-D vs. Allegra-D

Zyrtec-D (cetirizine/pseudoephedrine) and Allegra-D (fexofenadine/pseudoephedrine) are both over-the-counter medications used to treat seasonal allergies and congestion. They both contain pseudoephedrine, a decongestant that can cause trouble sleeping if taken too close to bedtime. They each contain different antihistamine components less likely to cause drowsiness than other antihistamines. Zyrtec-D contains cetirizine, which can still cause some sleepiness and dry mouth. Allegra-D contains fexofenadine, which may cause headaches or nausea. Zyrtec-D should be taken every 12 hours, while Allegra-D is available in both 12-hour and 24-hour formulations. Additionally, Allegra-D should be taken on an empty stomach and not with fruit juices, which can affect its absorption. Both medications require a photo ID for purchase due to the pseudoephedrine component and have restrictions on the amount you can buy. If you have high blood pressure, heart problems, or other specific health conditions, ask your prescriber or pharmacist before using either medication.