Brand Names: All Day Allergy, All Day Allergy Children's, Indoor/Outdoor Allergy Relief, Zyrtec, ZyrTEC Children's Dye-Free Sugar-Free, ZyrTEC Children's Perfect Measure, ZyrTEC Dissolve, Zyrtec Hives, ZyrTEC Liquid Gels

Generic Name: cetirizine (Pronunciation: se TIR a zeen)

• What is cetirizine (Zyrtec)?
• What are the possible side effects of cetirizine?
• What is the most important information I should know about cetirizine?
• What should I discuss with my healthcare provider before taking cetirizine?
• How should I take cetirizine?
• What happens if I miss a dose?
• What happens if I overdose?
• What should I avoid while taking cetirizine?
• What other drugs will affect cetirizine?
• Where can I get more information?

What is cetirizine (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.

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

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

Cetirizine may also be used for purposes not listed in this medication guide.

Cetirizine 5 mg-MYL

round, white, imprinted with C35, M

Zyrtec 10 mg

rectangular, white, imprinted with ZYRTEC, 10

Zyrtec 5 mg

rectangular, white, imprinted with ZYRTEC, 5

What are the possible side effects of cetirizine?

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

Call your doctor at once if you have a serious side effect such as:

• fast, pounding, or uneven heartbeat;
• weakness, tremors (uncontrolled shaking), or sleep problems (insomnia);
• severe restless feeling, hyperactivity;
• confusion;
• problems with vision; or
• urinating less than usual or not at all.

Less serious side effects may include:

• dizziness, drowsiness;
• tired feeling;
• dry mouth;
• sore throat, cough;
• nausea, constipation; or
• headache.

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.

Read the Zyrtec (cetirizine) Side Effects Center for a complete guide to possible side effects »

What is the most important information I should know about cetirizine?

This medication 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 cetirizine.

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