Description:

Zyrtec

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

Medically reviewed by Sophia Entringer, PharmD. Last updated on Jun 2, 2022.

What is Zyrtec?

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.

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).

Warnings

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 levocetirizine.

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

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Zyrtec pregnancy and breastfeeding warnings (more detail)

How should I use Zyrtec?

Zyrtec is taken by mouth.

Use Zyrtec exactly as directed on the label, or as prescribed by your doctor.

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

You may take this medicine with or without food.

Do not swallow the Zyrtec orally disintegrating tablet whole. Allow the tablet 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 Zyrtec Syrup carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

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

Store at room temperature away from moisture and heat. Do not allow liquid medicine to freeze.

Dosing information

Usual Adult Dose for Allergic Rhinitis:

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.

Usual Adult 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.

Uses:
-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

Usual Pediatric Dose for Allergic Rhinitis:

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

Uses:
-Relief of symptoms associated with perennial allergic rhinitis due to allergens (e.g., sneezing, rhinorrhea, postnasal discharge, nasal pruritus, ocular pruritus, tearing) in patients 2 years and older
-Treatment of uncomplicated skin manifestations of chronic idiopathic urticaria in patients 6 months and older

Detailed Zyrtec dosage information

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take 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 extreme drowsiness, vision problems, agitation, feeling restless and then drowsy or tired, fast heartbeats, stomach pain, nausea, vomiting, trouble walking, or 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. Your reactions could be impaired.

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:

drowsiness, tiredness;
dizziness, feeling light-headed;
feeling hot, sweating;
numbness, tingling, burning pain;
decreased sense of taste;
headache;
upset stomach, nausea, constipation; or
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 your current medicines and any medicine you start or stop using.

Zyrtec drug interactions (more detail)

Where can I get more 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.

Popular FAQ

How long does it take for cetirizine to work?

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.

How long after taking cetirizine can I drink alcohol?

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.

Can you take Benadryl and cetirizine together?

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.

Does cetirizine make you drowsy?

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.

Can cetirizine raise blood pressure?

Cetirizine does not increase blood pressure and blood pressure is not listed as a side effect in the product information. But cetirizine can be found in combination with other medications, such as pseudoephedrine in products such as Zyrtec-D, and pseudoephedrine does increase blood pressure.

More FAQ

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Related treatment guides

Urticaria
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Further information

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

Medical Disclaimer

Drug name: Zyrtec