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).
Zyrtec may also be used for purposes not listed in this medication guide.
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.
FDA pregnancy category B. Zyrtec 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 Zyrtec without telling your doctor if you are breast-feeding a baby.
Get emergency medical help if you have any of these signs of an allergic reaction to Zyrtec: 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;
- problems with vision; or
- urinating less than usual or not at all.
Less serious Zyrtec side effects may include:
- dizziness, drowsiness;
- tired feeling;
- dry mouth;
- sore throat, cough;
- nausea, constipation; or
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.