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Zyrtec

Generic Name: cetirizine (se TIR a zeen)
Brand Names: All Day Allergy, All Day Allergy Children's, Indoor/Outdoor Allergy Relief, Zyrtec

Medically reviewed on Mar 2, 2017

What is Zyrtec?

See also: Xolair

Zyrtec (cetirizine) is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Zyrtec is used to treat cold or allergy symptoms such as sneezing, itching, watery eyes, or runny nose.

Zyrtec is also used to treat itching and swelling caused by chronic urticaria (hives).

Important information

Zyrtec may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Drinking alcohol can increase certain side effects of Zyrtec.

Tell your doctor if you regularly use other medicines that make you sleepy (such as other cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to sleepiness caused by Zyrtec. Call your doctor if your symptoms do not improve, if they get worse, or if you also have a fever.

Before taking this medicine

You should not use Zyrtec if you are allergic to cetirizine.

Ask a doctor or pharmacist if it is safe for you to take this medicine if you have any medical conditions.

It is not known whether Zyrtec will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.

It is not known whether cetirizine passes into breast milk or if it could harm a nursing baby. Ask a doctor before using this medicine if you are breast-feeding a baby.

How should I take Zyrtec?

Use Zyrtec exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Older adults may need to take a lower than normal dose. Follow your doctor's instructions.

You may take Zyrtec with or without food.

The chewable tablet must be chewed before you swallow it.

Do not swallow the dissolving tablet whole. Allow it to dissolve in your mouth without chewing. Swallow several times as the tablet dissolves. If desired, you may drink liquid to help swallow the dissolved tablet.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Call your doctor if your symptoms do not improve, if they get worse, or if you also have a fever.

Store Zyrtec at room temperature away from moisture and heat. Do not allow the liquid form of this medicine to freeze.

Zyrtec dosing information

Usual Adult Dose for Allergic Rhinitis:

5 to 10 mg orally or chewed once a day

Usual Adult Dose for Urticaria:

5 to 10 mg orally or chewed once a day

Usual Pediatric Dose for Allergic Rhinitis:

6 months to 2 years: 2.5 mg orally once a day, 12 months and older may be increased to 2.5 mg orally twice a day.

2 to 5 years: 2.5 mg orally once a day, may be increased to 5 mg/day in 1 to 2 divided doses.

6 years or older: 5 to 10 mg orally or chewed once a day.

Usual Pediatric Dose for Urticaria:

6 months to 2 years: 2.5 mg orally once a day, 12 months and older may be increased to 2.5 mg orally twice a day.

2 to 5 years: 2.5 mg orally once a day, may be increased to 5 mg/day in 1 to 2 divided doses.

6 years or older: 5 to 10 mg orally or chewed once a day.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include feeling restless or nervous, and then feeling drowsy.

What should I avoid while taking Zyrtec?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid drinking alcohol while taking Zyrtec.

Zyrtec side effects

Get emergency medical help if you have signs of an allergic reaction to Zyrtec: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop taking this medicine and call your doctor at once if you have:

  • fast, pounding, or uneven heartbeat;

  • weakness, tremors (uncontrolled shaking), or sleep problems (insomnia);

  • severe restless feeling, hyperactivity;

  • confusion;

  • problems with vision; or

  • little or no urination.

Common Zyrtec side effects may include:

  • dizziness, drowsiness;

  • dry mouth;

  • nausea, constipation; or

  • tired feeling.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Zyrtec?

Taking Zyrtec with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking a sleeping pill, narcotic medication, muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with cetirizine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Zyrtec only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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