Zyrtec Drug Warnings and Side Effects

Medically reviewed by

Updated on January 07, 2020

Zyrtec is an over-the-counter medication used to relieve symptoms of seasonal allergies such as itching, sneezing, and runny nose. Zyrtec is the brand name for the drug cetirizine. It is available for adults and children over 2 years old.

Active Ingredient

Cetirizine

Dosage and Directions

Adults and children ages 6 to 64:

One (10 mg) tablet every 24 hours
One to two 5 mg chewable tablets every 24 hours depending on the severity of symptoms

Children ages 2 to 6 years old and adults over age 65:

One half (2.5 mg) to one (5 mg) teaspoon every 24 hours depending on the severity of symptoms

Children under 2 years old:

Ask a doctor

Purpose

Zyrtec is used to relieve symptoms of seasonal allergies, hay fever, and hives which include:

Runny nose
Sneezing
Itchy eyes, nose or throat
Itchy rash (hives)

Side Effects

Although most people don't experience significant side effects with this medicine, some may occur. Possible side effects of Zyrtec include:

Drowsiness
Dry Mouth
Irritability
Loss of sleep
Sore throat
Stomach pain
Swelling

If any of these symptoms are severe or do not go away, contact your health care provider.

Certain side effects can be very serious. If you have any of the following after taking Zyrtec or cetirizine, seek medical advice immediately.

Symptoms of an allergic reaction such as hives, itching, skin rash, swelling of face, lips or tongue
Changes in vision or hearing
Fast heartbeat
High blood pressure
Infection
Trouble urinating or change in the amount of urine

Warnings

If you have hives and experience difficulty breathing, significant swelling of the tongue or lips, wheezing, difficulty speaking or swallowing, dizziness, drooling, vomiting or loss of consciousness, seek emergency medical attention immediately. These are signs of a potentially life-threatening allergic reaction known as anaphylaxis.

Ask a Doctor Before Using Zyrtec

If you have any of the following conditions, ask your health care provider before using Zyrtec:

You are allergic to Zyrtec, cetirizine, hydroxyzine, or any other medications.
You have liver disease.
You have kidney disease.
You are pregnant, plan to become pregnant or are breastfeeding.

Zyrtec is a great over the counter antihistamine and is generally very effective at relieving allergy symptoms. Some people try taking it for runny nose or congestion caused by colds and respiratory infections, but antihistamines typically don't work well against these illnesses.

If you have never taken Zyrtec or an antihistamine before, be aware that it could make you drowsy. Don't take it for the first time if you need to drive or work before you know how it will affect you.

This medicine is considered safe and effective for most people, but if you aren't sure or have questions about how it will work for you, talk to your health care provider before taking it.