Zyrtec - Hydrochlorothiazide Interaction Details

Answer

Hi and thank you for your great question. I always appreciate it when our readers reach out and ask to double-check that their prescription medications are safe with their OTC drugs.

The good news is that there are no known drug interactions between these two medications in question (Zyrtec and hydrochlorothiazide). They are considered safe to take together. In fact, hydrochlorothiazide is safe with all of the other second-generation antihistamines, including Claritin, Xyzal, and Allegra.

I do want to point out that a small percentage (around 10%) of individuals feel drowsy on Zyrtec. This is a side effect that can sometimes happen with hydrochlorothiazide as well, especially when you first start it, so please be aware of that.

What Is Zyrtec?

Cetirizine (or by the brand Zyrtec) is a “second generation” antihistamine.

It works by binding to histamine receptors in the body so that histamine can’t bind to them. This helps to reduce the symptoms typically caused by allergies such as a runny nose, watery eyes and sneezing. It is generally well tolerated and lasts about 24 hours although, as mentioned, it can cause drowsiness.

What Is Hydrochlorothiazide?

Hydrochlorothiazide, or HCTZ, is a 'thiazide' diuretic medication that’s commonly used to treat high blood pressure and swelling due to fluid buildup. It’s a very inexpensive and a common first-line therapy to treat high blood pressure and related cardiac conditions.  

Final Words

Thanks for reaching out to us and I hope this helps.