Common uses
Zyrtec (CETIRIZINE) is an antihistamine used to treat both seasonal and perennial allergy symptoms such as watery eyes, runny nose (rhinitis), itching eyes, and sneezing. Cetirizine is also used to treat hives.

Before using
Additional monitoring of your dose or condition may be needed if you are taking other medicines that cause drowsiness such as medicine for sleep (e.g., sedatives), tranquilizers, anti-anxiety medicines (e.g., diazepam), narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., phenothiazines such as chlorpromazine, or tricyclics such as amitriptyline), anti-seizure medicines (e.g., carbamazepine), muscle relaxants, or other antihistamines that cause drowsiness (e.g., diphenhydramine).

Do not start or stop any medicine without doctor or pharmacist approval. Inform your doctor of any other medical conditions, allergies, pregnancy, or breast-feeding. Do not take this medicine if you have an allergy to the medicine hydroxyzine. Additional monitoring of your dose may be needed if you have a history of kidney disease, or liver disease. Contact your doctor or pharmacist if you have any questions or concerns about taking this medicine.

Directions
Follow the directions for using this medicine provided by your doctor. This medicine is usually taken by mouth once daily. This medicine may be taken on an empty stomach or with food. Store this medicine at room temperature between 68 and 77 degrees f (20 to 25 degrees c) in a tightly-closed container, away from heat, moisture, and light.

Brief storage between 59 and 86 degrees f (15 and 30 degrees c) is acceptable. If you miss a dose of this medicine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Cautions
This medicine may cause drowsiness. Do not drive, operate machinery, or do anything else that could be dangerous until you know how you react to this medicine. Using this medicine alone, with other medicines, or with alcohol may lessen your ability to drive or to perform other potentially dangerous tasks.

Limit alcoholic beverages while taking this medicine. Do not increase your dose or take more of this medicine than prescribed without checking with your doctor. Before you begin taking any new medicine, either prescription or over-the-counter (e.g., cough-and-cold products), check with your doctor or pharmacist about their safe use. These medicines may also contain ingredients which can cause drowsiness. This medicine may interfere with allergy test results. Check with your doctor for instruction on how long you will need to stop taking this medicine prior to those tests.

caution is advised when using this medicine in the elderly because they may be more sensitive to the effects of this medicine, especially the drowsiness effect. For women: if you plan on becoming pregnant, discuss with your doctor the benefits and the risks of using this medicine during pregnancy. This medicine is excreted in breast milk. Do not breast-feed while taking this medicine.

Possible side effects
Side effects, that may go away during treatment, include drowsiness, fatigue, or dry mouth. In children, stomach pain or vomiting may occur. If they continue or are bothersome, check with your doctor. Contact your doctor immediately if you experience yellowing of eyes or skin, dark urine, or persistent fatigue. An allergic reaction to this medicine is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include rash, itching, swelling, dizziness, or trouble breathing. If you notice other effects not listed above, contact your doctor, nurse, or pharmacist.

If you take too much
If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include severe drowsiness. In children symptoms may include restlessness and irritability at first followed by drowsiness.

Additional information
Carry an identification card at all times that says you are taking this medicine. If your symptoms do not improve or if they become worse, contact your doctor. Do not share this medicine with others for whom it was not prescribed.

Do not use this medicine for other health conditions. Keep this medicine out of the reach of children and pets. If using this medicine for an extended period of time, obtain refills before your supply runs out.

Drug interactions
Drug interactions can result in unwanted side effects or prevent a medicine from doing its job. Some medicines or medical conditions may interact with this medicine. Inform your doctor or pharmacist of all prescription and over-the-counter medicine that you are taking.