Claritin Vs. Singulair: What Is The Difference?

In our latest question and answer, the pharmacist discusses the difference between Claritin (loratadine) and Singulair (montelukast).

Jan 18, 2018

Joanne asked

What is the difference between Singulair and Claritin?


Claritin (loratadine) and Singulair (montelukast) are both medications that can be used to treat allergic rhinitis (i.e. seasonal allergies). However, there are several differences between these medications that will be discussed below.

Claritin Vs. Singulair Overview
Although both Claritin and Singulair can be used for allergic rhinitis, there are differences in the other indications that these medications have been FDA approved. The primary use for Claritin is for treatment of allergy symptoms including itching, runny nose, sneezing, and hives. Claritin has also been used off-label for exercise-induced breathing issues.

Singulair has been approved for the treatment of allergies as well, but Singulair can also be used asthma and for prevention of exercise-induced breathing issues.

The mechanism of these medications is different as well. Claritin is a part of a medication class known as antihistamines. Specifically, Claritin is a second-generation antihistamine. Other second-generation antihistamines include Allegra (fexofenadine) and Zyrtec (cetirizine). Antihistamines bind to histamine receptors that are found in the nose, lungs, eyes, and skin without activating the histamine response. Histamine creates an immune response to essentially attempt to remove the offensive allergen. Antihistamines are useful in preventing the immune cascade so common in people suffering from allergies. Claritin was first approved in 1993 as a prescription medication, but was later approved for over the counter use in 2002.

Singulair is a leukotriene receptor antagonist, meaning it blocks the activity of leukotrienes. Leukotrienes are released in response to allergens like pollen, dust, and pet dander. By blocking leukotriene, Singulair limits the pathway that causes asthma and allergy symptoms. Leukotriene is recommended in chronic asthma patients as an alternate to inhaled corticosteroids.  Singulair was first approved in 1998 for asthma in adults, but was later approved for children in 2000.

Another major difference between these two medications is the availability of each medication. Claritin is available via prescription and over-the-counter. Singulair is only available via prescription. Both medications are now available as generic medications.


All in all, the main difference between Singulair and Claritin is that Singulair can be used for asthma, whereas Claritin is only approved for use for allergy symptoms. These medications also have a different mechanism of action. Additionally, Singulair is only available via prescription.


Sources: Claritin and Singulair package inserts

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