Cetirizine is an antihistamine used to relieve allergy symptoms such as watery eyes, runny nose, itching eyes/nose, sneezing, hives, and itching. It works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. Cetirizine does not prevent hives or prevent/treat a serious allergic reaction (such as anaphylaxis). Therefore, if your doctor has prescribed epinephrine to treat allergic reactions, always carry your epinephrine injector with you. Do not use cetirizine in place of your epinephrine.
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.
Side Effects of Cetirizine
Get emergency medical help if you have any of these signs of an allergic reaction: 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 sleeping problems.
- Severe restless feeling, hyperactivity.
- Problems with vision.
- Urinating less than usual or not at all.
Less serious side effects:
- Dizziness, drowsiness;
- Tired feeling;
- Dry mouth;
- Sore throat, cough;
- Nausea, constipation; or