Cetirizine is a second generation antihistamine that reduces the 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 an allergic reaction, itching and swelling caused by chronic urticaria (hives) and minimizes or eliminates the symptoms of perennial allergic rhinitis, seasonal allergic rhinitis, chronic idiopathic urticaria, allergic asthma, physical urticaria, and atopic dermatitis.

Cetirizine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert. Avoid drinking alcohol. It can increase some of the 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.

Take cetirizine exactly as directed on the label, or as prescribed by your doctor. Do not use it in larger amounts or for longer than recommended.

You may take cetirizine with or without food.

The chewable tablet must be chewed before you swallow it.

Oral doses: measure liquid medicine (oral solution) with a special dose-measuring spoon or cup, not a regular table spoon. 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 cetirizine at room temperature away from moisture and heat.

You should not use this medication if you are allergic to or had an adverse reaction to cetirizine.

Before taking cetirizine, tell your doctor about all of your medical conditions or if you have ever had kidney or liver disease.

Cetirizine is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Cetirizine can pass into breast milk and may harm a nursing baby. Do not use cetirizine without telling your doctor if you are breast-feeding a baby.

Cetirizine is indicated for chronic idiopathic urticaria in adults and children 6 months of age and older.

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

Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine or add extra doses to make up the missed dose.

Seek emergency medical attention if you think you have used too much of this medicine.

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

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.

Cetirizine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid drinking alcohol. It can increase some of the side effects of cetirizine.

Get emergency medical help if you have any serious adverse effects or any of these signs of an allergic reaction: chronic idiopathic urticaria (hives); difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using cetirizine and call your doctor at once if you have any of these serious side effects:

• 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 cetirizine 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. Tell your doctor about any unusual or bothersome side effect.

There may be other drugs that can interact with cetirizine. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.