Can You Take Zyrtec And Singulair Together?
In our latest question and answer, the pharmacist discusses if Zyrtec and Singulair can safely be used together.
I was told by my doctor to use Zyrtec, and it's been helpful for allergies. I still need some help though and I was reading about Singulair. Is it safe to use that even though I'm already taking an antihistamine?
Nov 22, 2022- Zyrtec and Singulair can be safely taken together with no drug interaction between them.
- The two medications work through different mechanisms to reduce allergy symptoms and may be more effective when combined than either drug alone.
Answer
Yes, Zyrtec (cetirizine) and Singulair (montelukast) can safely be taken together. There is no drug interaction between them.
Both drugs work via different mechanisms and do not interfere with one another. In fact, several studies show that combining an antihistamine, like Zyrtec, and a leukotriene receptor antagonist (LTRA), like Singulair, can be more effective in treating allergy symptoms than either drug alone (although data is mixed in this regard).
What Do Studies Show?
As mentioned, you may get the most relief of your allergy symptoms if you combine drugs like Zyrtec and Singulair.
One study, which evaluated the combination of antihistamines and leukotriene antagonists, concluded the following:
The current evidence suggests that LTRAs [leukotriene receptor antagonists such as Singulair] + H1 [histamine-1 blockers, like Zyrtec] can increase the therapeutic efficacy against daytime and composite nasal symptoms, including rhinorrhea, sneezing, and itching...
Other studies have found somewhat conflicting results, but there is no interaction between the drugs, and they, at the very least, won't alter how the other works.
Zyrtec And Singulair Work In Different Ways
Zyrtec and Singulair work via different pathways to help treat allergy symptoms.
Zyrtec is a second-generation antihistamine, which blocks the H1 (histamine-1) receptor, preventing histamine from binding to it (which prevents the histamine-induced inflammatory response).
Singulair blocks the leukotriene D4 (LTD4) receptor. This, in turn, blocks the action of several different substances in the body that cause allergy symptoms.
Although Zyrtec and Singulair prevent the release of similar substances (e.g., mast cells, eosinophils), they do so differently.
Final Words
I hope you found this helpful!
I also hope you find your new therapy of Zyrtec and Singulair effective. I know how challenging it can be to find effective therapies to treat allergies.
Thanks for reaching out!
References & sources
- Pharmacotherapy for allergic rhinitis: a critical review of leukotriene receptor antagonists compared with other treatments — Science Direct
- Oral Antihistamines Alone vs in Combination with Leukotriene Receptor Antagonists for Allergic Rhinitis: A Meta-analysis — PubMed
- Role of leukotriene antagonists and antihistamines in the treatment of allergic rhinitis — PubMed
- Management of allergic rhinitis with leukotriene receptor antagonists versus selective H1-antihistamines: a meta-analysis of current evidence — Allergy, Asthma & Clinical Immunology
Glossary — Terms in This Answer
- Antihistamine
- A medication that blocks histamine, a chemical in the body that causes allergy symptoms like itching and sneezing.
- Leukotriene receptor antagonist
- A medication that blocks leukotriene receptors, which are involved in the body's allergic response.
- Drug interaction
- A situation where two medications affect each other's effectiveness or safety when taken together.
- Histamine-1 receptor
- A specific target site on cells where histamine attaches to trigger allergy symptoms.
- Leukotriene D4 receptor
- A specific target site on cells where a chemical messenger called leukotriene D4 attaches to cause allergic inflammation.
- Therapeutic efficacy
- The ability of a treatment to produce the desired healing or symptom-relief effect.
- Mast cells
- Immune cells in the body that release histamine and other chemicals during an allergic reaction.
- Eosinophils
- A type of white blood cell that helps trigger allergic and inflammatory responses in the body.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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