Zyrtec Uses, Dosage & Side Effects - Drugs.com (2024)

Generic name: cetirizine [se-TIR-a-zeen]
Drug class: Antihistamines

Medically reviewed by Sophia Entringer, PharmD. Last updated on Aug 22, 2023.

What is Zyrtec?

Zyrtec is used in adults and children 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).

Zyrtec 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.


Before using Zyrtec tell your doctor about all your medical conditions or allergies, all medicines you use, and if you are pregnant or breastfeeding.

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 cetirizine.

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 or similar medicines such as: levocetirizine or hydroxyzine.

Ask a doctor or pharmacist before using Zyrtec if you have any health problems.

To make sure Zyrtec is safe for you, tell your doctor if you have ever had:

  • recently used alcohol, sedatives, or tranquilizers; or

  • liver or kidney disease.

Tell your doctor if you are pregnant or breastfeeding.

Zyrtec pregnancy and breastfeeding warnings (more detail)

How should I use Zyrtec?

Take Zyrtece xactly as directed. Follow all directions on your prescription label and read all medication guides or instruction sheets.

Zyrtec can be taken with or without food.

You must chew the chewable tablet before you swallow it.

Remove an orally disintegrating tablet from the blister pack with dry hands only when you are ready to take the medicine. Take this medicine immediately after opening the blister pack. Allow the orally disintegrating tablet to dissolve in your mouth without chewing.

Measure liquid medicine with the supplied measuring device (not a kitchen spoon).

Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using exactly as directed on the label, or as prescribed by your doctor.

Call your doctor if your symptoms do not improve, or if they get worse.

Store at room temperature away from moisture, heat, and light.

Dosing information

Usual Adult Dose for Allergic Rhinitis:

5 to 10 mg orally once a day
-Maximum dose: 10 mg/day.

Usual Adult Dose for Urticaria:

5 to 10 mg orally once a day
-Maximum dose: 10 mg/day.

Usual Geriatric Dose for Allergic Rhinitis:

5 to 10 mg orally once a day
-Maximum dose: 10 mg/day.

Usual Geriatric Dose for Urticaria:

5 to 10 mg orally once a day
-Maximum dose: 10 mg/day

-Some experts recommend: Patients over 65 years of age should start with 5 mg orally once a day.

-Relief of symptoms associated with perennial allergic rhinitis due to allergens (e.g., sneezing, rhinorrhea, postnasal discharge, nasal pruritus, ocular pruritus, tearing)
-Treatment of uncomplicated skin manifestations of chronic idiopathic urticaria

American Academy of Otolaryngology (AAO) and Head and Neck Surgery Foundation (HNSF) recommendations:
66 to 76 years: 5 to 10 mg orally per day
77 years and older: 5 mg orally per day
Duration of therapy: 6 months or longer

-Intranasal antihistamines may be used concomitantly for patients with episodic, perennial, and/or seasonal allergic rhinitis.

Use: Treatment of allergic rhinitis and sneezing and itching

Usual Pediatric Dose for Allergic Rhinitis:

6 months to 2 years:
-Initial dose: 2.5 mg orally once a day
-Maintenance dose: 2.5 mg orally once to 2 times a day
-Maximum dose: 5 mg/day

2 to 5 years:
-Initial dose: 2.5 mg orally once a day
-Maintenance dose: 2.5 mg orally 2 times a day OR 5 mg orally once a day
-Maximum dose: 5 mg/day

6 years and older: 5 to 10 mg orally once a day
-Maximum dose: 10 mg/day.

Usual Pediatric Dose for Urticaria:

6 months to 2 years:
-Initial dose: 2.5 mg orally once a day
-Maintenance dose: 2.5 mg orally once to 2 times a day
-Maximum dose: 5 mg/day

2 to 5 years:
-Initial dose: 2.5 mg orally once a day
-Maintenance dose: 2.5 mg orally 2 times a day OR 5 mg orally once a day
-Maximum dose: 5 mg/day

6 years and older: 5 to 10 mg orally once a day
-Maximum dose: 10 mg/day.

Detailed Zyrtec dosage information

What happens if I miss a dose?

Zyrtec is used when needed. If you are on a dosing schedule, skip any missed dose. Do not use two doses at one time.

What happens if I overdose?

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

Overdose symptoms may include severe drowsiness, vision problems, agitation, fast heartbeats, stomach pain, nausea, vomiting, trouble walking, trouble swallowing or speaking.

What should I avoid while using Zyrtec?

Avoid driving or hazardous activity until you know how this medicine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Drinking alcohol with this medicine can cause side effects.

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.

Common Zyrtec side effects may include:

  • nausea, vomiting, diarrhea;

  • cough, drowsiness, tiredness;

  • headache, dizziness, feeling light-headed;

  • feeling hot, sweating;

  • numbness, tingling, burning pain;

  • altered sense of taste;

  • upset stomach, constipation; or

  • nosebleed, dry mouth, sore throat.

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.

Zyrtec side effects (more detail)

What other drugs will affect Zyrtec?

Using Zyrtec with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Other drugs may interact with cetirizine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Zyrtec drug interactions (more detail)

Popular FAQ

Cetirizine will start to work within one hour after you take it. It provides allergy relief for 24-hours. It relieves symptoms like sneezing, runny nose, itchy and watery eyes, and itchy nose or throat. If it makes you drowsy, you can take it at bedtime, or as directed by your doctor.

Benadryl should not be taken at the same time as cetirizine because it can increase side effects such as dizziness, drowsiness, and difficulty concentrating. Some people, especially the elderly or children, may also find their thinking, judgement, and coordination impaired. You should also not drink alcohol while taking either of these medications because it can make these side effects worse.

It is best to wait until cetirizine completely leaves your body before you drink alcohol, which may take up to 40 hours (almost 2 days). This is because alcohol can increase the nervous system side effects of cetirizine such as dizziness, drowsiness, and difficulty concentrating. Some people may also find it difficult to think or make good judgements. This calculation is based on the half-life of cetirizine, which is 8.3 hours, and experts say it takes 4 to 5 half-lives for a drug to fully leave your body which works out to 33 to 40 hours.

Cetirizine is classed as a non-drowsy (non-sedating) antihistamine, but it does make some people drowsy. In clinical trials, this side effect appeared to be related to the dose of cetirizine, with higher dosages increasing the risk of feeling drowsy. 1.9% of children aged 6 to 11 years experienced drowsiness with 5mg of cetirizine and 4.2% of children experienced drowsiness with 10mg of cetirizine. Up to 14.3% of adults may be affected by drowsiness with cetirizine.

More FAQ

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  • Can you take antihistamines when pregnant?
  • I took Zyrtec for 1 year but have now stopped. How long does it stay in the body?
  • Is Generic Zyrtec Available?

View more FAQ

More about Zyrtec (cetirizine)

  • Check interactions
  • Compare alternatives
  • Reviews (197)
  • Drug images
  • Latest FDA alerts (1)
  • Side effects
  • Dosage information
  • Patient tips
  • During pregnancy
  • Support group
  • Drug class: antihistamines
  • Breastfeeding

Patient resources

  • Zyrtec (Cetirizine Capsules and Tablets) patient information
  • Zyrtec (Cetirizine Chewable Tablets)
  • Zyrtec (Cetirizine Liquid)
  • Zyrtec (Cetirizine Orally Disintegrating Tablets)

Other brands


Professional resources

  • Zyrtec prescribing information
  • Zyrtec Tablets (FDA)
  • Cetirizine (AHFS Monograph)

Other brands

Aller-Tec, Quzyttir, All Day Allergy, All Day Allergy Children's, Aller-Tec Children's

Other formulations

  • Zyrtec-D
  • Zyrtec-D 12 Hour

Related treatment guides

  • Allergic Rhinitis
  • Urticaria
  • Allergies

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 circ*mstances.

Medical Disclaimer

Copyright 1996-2024 Cerner Multum, Inc. Version: 13.01.

Zyrtec Uses, Dosage & Side Effects - Drugs.com (2024)


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