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Uses|Precautions & Warnings|Side Effects|Interactions|Dosage


Zyrtec® (cetirizine) is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

Zyrtec® is used to temporarily relieve the symptoms of:

  • Hay fever
  • Allergic rhinitis
  • Skin allergies
  • Rashes
  • Sneezing
  • Runny nose
  • Itchy, watery eyes

How should I take Zyrtec®?

Zyrtec® comes as a tablet, a chewable tablet, an extended-release tablet, and a syrup (liquid) to take by mouth. It is usually taken once a day with or without food. Take Zyrtec® at around the same time every day. Follow the directions on your package label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take Zyrtec® exactly as directed. Do not take more or less of it or take it more often than directed on the package label or as recommended by your doctor.

Do not use Zyrtec® to treat hives that are bruised or blistered, that are an unusual color, or that do not itch. Call your doctor if you have these types of hives.

Stop taking Zyrtec® and call your doctor if your hives do not improve during the first 3 days of your treatment or if your hives last longer than 6 weeks. If you do not know the cause of your hives, call your doctor.

How do I store Zyrtec®?

Zyrtec® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Zyrtec® in the bathroom or the freezer. There may be different brands of Zyrtec® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Zyrtec® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & Warnings

Before using this drug, tell your doctor if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of the active or inactive ingredients of Zyrtec® or other medications.
  • You have any other illnesses, disorders, or medical conditions.

Zyrtec® may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.

Alcohol can add to the drowsiness caused by this medication. Avoid drinking alcoholic beverages while taking this medication.

Is it safe during pregnancy or breastfeeding?

Zyrtec® is a pregnancy risk category B, according to the US Food and Drug Administration (FDA).

There are no adequate studies in women for determining risk when using Zyrtec® during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Zyrtec®.

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side Effects

All drugs have the potential to elicit side effects even with normal use. Many side effects are dose-related and will resolve when it is adjusted or at the end of therapy.

Potential side effects while using Zyrtec® include:

  • Headache
  • Pharyngitis
  • Abdominal pain
  • Coughing
  • Drowsiness
  • Diarrhea
  • Nosebleeds
  • Bronchospasm
  • Nausea
  • Vomiting

You may experience some, none, or other side effects not mentioned above. If you experience serious adverse reactions, you must stop taking the drug immediately. If you have any concerns about a side effect or it becomes bothersome, consult your doctor or pharmacist.


Zyrtec® may interact with other medications. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist.

Known drugs that interact with medication include:

  • Theophylline
  • Sedatives
  • Other antihistamines
  • Alcohol-containing medications

Does food or alcohol interact with Zyrtec®?

There are no known food interactions with Zyrtec®. Do not take Zyrtec® with alcohol as it may potentiate the effects of drowsiness and CNS depression.

Inform your doctor or pharmacist if you have any concerns regarding food-drug interactions.

What health conditions may interact with Zyrtec®?

Zyrtec® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

This drug should be taken with caution if you have any of the following conditions or risk factors:

  • Kidney disease
  • Liver disease


The information provided is not a substitute for any medical advice. You should ALWAYS consult your doctor or pharmacist before using Zyrtec®.

What is the dose of Zyrtec® for an adult?

The recommended initial dose of Zyrtec® is 5 or 10 mg per day in adults and children 12 years and older, depending on symptom severity.

Zyrtec® is given as a single daily dose, with or without food. The time of administration may be varied to suit individual patient needs.

What is the dose of Zyrtec® for a child?

Children 6 to 12 years:

Give 5 or 10 mg (1 or 2 teaspoons) once daily depending on symptom severity. The time of administration may be varied to suit individual patient needs.

2 to 5 years old:

Give 2.5 mg (½ teaspoon) once daily. The dosage can be increased to a maximum dose of 5 mg per day given as 1 teaspoon (5 mg) once daily, or as ½ teaspoon (2.5 mg) given every 12 hours.

6 months to <2 years:

Give 2.5 mg (½ teaspoon) once daily. The dose can be increased to a maximum dose of 5 mg per day, given as ½ teaspoonful (2.5 mg) every 12 hours.

How is Zyrtec® available?

Zyrtec® is available in the following dosage forms and strengths:

  • Tablet 5 mg, 10mg
  • Syrup 5 mg/5 mL

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Zyrtec®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.


https://www.accessdata.fda.gov/drugsatfda_docs/label/2002/19835s15,%2020346s8lbl.pdf, Accessed Sept 10, 2020


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Written by Stephanie Nicole Nera, RPh, PharmD Updated Dec 03, 2020