Can You Take Zyrtec And Pepcid Together?
In our latest question and answer, the pharmacist discusses whether or not Zyrtec can be safely taken with Pepcid.
Is it safe to take Zyrtec and famotidine together? I understand they help reduce allergic reactions. I have been having allergic reactions that I'm told are not actual allergies.
Nov 01, 2022- There is no known drug interaction between Zyrtec and Pepcid, and they are considered safe to take together.
- Both drugs block histamine but affect different receptors, and combining them may actually work better than using either drug alone for certain conditions.
Answer
There is no known drug interaction between Zyrtec (cetirizine) and Pepcid (famotidine). They are considered safe to take together.
Even though both of these drugs work by blocking histamine, they affect different histamine receptors, and can have a synergistic effect when used together.
How Does Zyrtec Work?
Zyrtec is a second-generation antihistamine, also known as an H1-blocker.
It works by binding to histamine H1-receptors. This prevents histamine from binding to these receptors, which would cause the release of a number of natural substances in the body that cause well known allergy symptoms (e.g., itching, runny nose, sneezing, redness, hives etc...).
Second-generation antihistamines are, in general, longer lasting, and cause less sedation, than first-generation antihistamines (like Benadryl).
How Does Pepcid Work?
Pepcid (famotidine) is an H2-blocker. So, like Zyrtec, it blocks histamine receptors, just a different type.
Pepcid binding to H2 receptors blocks histamine from binding, which reduces stomach acid secretion.
Combined Use Of H1 & H2-Receptor Blockers
As mentioned above, it is safe to combine Zyrtec and Pepcid.
In fact, several studies have shown that combining drugs that work on these different receptors can be very effective for certain conditions.
For example, one study concluded the following:
This study indicates that combined H1 and H2 antihistamine therapy is statistically more effective than H1 antihistamines alone in controlling the symptoms of chronic urticaria [itching].
Several other studies have found similar results.
It sounds like, in your situation, taking Zyrtec and Pepcid may work better than either drug alone to help drug the symptoms you are experiencing from your allergic reaction.
Final Words
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References & sources
- Dual-histamine receptor blockade with cetirizine - famotidine reduces pulmonary symptoms in COVID-19 patients — PubMed
- Combined H1 and H2 antihistamine therapy in chronic urticaria — PubMed
- Evaluation of combined H1- and H2-receptor blocking agents in the treatment of seasonal allergic rhinitis — PubMed
- Treatment of chronic idiopathic urticaria with combined H1 and H2 blockers — PubMed
Glossary — Terms in This Answer
- Antihistamine
- A medication that blocks histamine, a chemical in the body that causes allergy symptoms like itching and sneezing.
- H1-blocker
- A type of antihistamine that blocks histamine from attaching to H1-receptors on cells, preventing allergy symptoms.
- H2-blocker
- A medication that blocks histamine from attaching to H2-receptors, which reduces the amount of stomach acid produced.
- Histamine receptors
- Specific binding sites on cells where histamine attaches to trigger various effects in the body.
- Synergistic effect
- When two medications work together to produce a stronger combined effect than either would produce alone.
- Second-generation antihistamine
- A newer type of allergy medication that lasts longer and causes less drowsiness than older antihistamines.
- Chronic urticaria
- A long-lasting condition causing persistent itching and raised welts on the skin due to allergic reaction.
- Drug interaction
- A reaction that occurs when two medications affect each other's effectiveness or safety when taken together.
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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