Allegra D Vs. Claritin D

Allegra D and Claritin D are both used to treat allergic rhinitis, or hay fever symptoms with sinus congestion, according to 12. Both drugs use the combination of an antihistamine and decongestant to address the symptoms of sneezing, a runny nose, congestion, eye irritation and postnasal drip. Consult with an allergist to determine the best treatment approach.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.


Both drugs use the same decongestant drug, pseudoephedrine, to treat nasal congestion. Pseudoephedrine works by restricting blood flow to the sinus cavity, reducing inflammation. This drug can increase a person’s heart rate and make the user feel excited or irritable. Both drugs are available in 12 or 24 hour doses, according to 12. They both use an antihistamine that is classified as non-sedating.


Allegra D’s active antihistamine ingredient is fexofenadine, while Claritin D uses loratadine 12. Fexofenadine is not for everyone and should not be administered to children under 2 without a doctor’s recommendation, according to the National Library of Medicine. Allegra D is acquired by prescription only, while Claritin D is available over-the-counter 12. In some states Claritin D is kept behind the counter at pharmacies because of the pseudoephedrine component 1.


The function of both medications is two-fold. The function of fexofenadine and loratadine is to block the body’s ability to produce histamine, the hormone that causes allergy symptoms. Taking either of these medications will inhibit the mast cells in the body from over-producing histamine, according to 12. The decongestant ingredient is for the purpose of reducing nasal congestion so the user can breathe normally.

Side Effects

Claritin D side effects include:

  • dry mouth
  • nausea
  • constipation
  • loss of appetite
  • dizziness
  • ringing in the ears
  • blurred vision
  • restlessness
  • skin rash
  • fast heartbeat
  • easy bruising
  • mental confusion
  • according to 12


Claritin D is less expensive and time-consuming to obtain because it is available over-the-counter 1. Many generic medications are available with the same active ingredients as Claritin D. Allegra D is more expensive than Claritin D and has one generic counterpart currently available according to 12.