Allergy

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used for shaking (tremor) and muscle stiffness caused by Parkinson's disease. It may also be used for side effects of certain psychiatric drugs such as involuntary movements and muscle stiffness (such as EPS). It works by blocking acetylcholine (see also Uses section).

If you are taking the over-the-counter product to self-treat, read all directions on the product package before taking this medication. If you have any questions, consult your pharmacist. If your doctor has prescribed this medication, take it as directed, usually once daily.

If you are using the chewable tablets, chew each tablet well and swallow. If you are using the rapidly-dissolving tablet, allow the tablet to dissolve on the tongue and then swallow, with or without water. If you are using the liquid form of this medication, measure the dose carefully using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

The dosage is based on your age, medical condition, and response to treatment. Do not increase your dose or take this medication more often than directed.

Tell your doctor if your allergy symptoms do not get better, if your hives do not improve after 3 days of treatment, or if your hives last more than 6 weeks. Get medical help right away if your condition gets worse or if you think you have a serious medical problem (such as a very serious allergic reaction/anaphylaxis).

Drowsiness, tiredness, and dry mouth may occur. Stomach pain may also occur, especially in children. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

If your doctor has prescribed this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: difficulty urinating, weakness.

Rarely, severe itching may occur after stopping the long-term use of this medication (taking the medication for a few months to years). Talk to your doctor about the risks and benefits of this medication, especially if you are using it regularly for a long time. Tell your doctor right away if itching occurs after stopping the medication.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking cetirizine, tell your doctor or pharmacist if you are allergic to it; or to hydroxyzine; or to levocetirizine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: difficulty urinating (such as due to an enlarged prostate), kidney disease, liver disease.

If you are using this medication to treat hives, tell your doctor right away if you have any of these other symptoms because they may be signs of a more serious condition: hives that are an unusual color, hives that look bruised or blistered, hives that do not itch.

This drug may make you drowsy. Alcohol or marijuana (cannabis) can make you more drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Liquid products may contain sugar. Caution is advised if you have diabetes. Ask your doctor or pharmacist about using this product safely.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or other antihistamines (such as chlorpheniramine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

Do not use with any other antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray) because increased side effects may occur.

Cetirizine is very similar to hydroxyzine and levocetirizine. Do not use these medications while using cetirizine.

This medication may interfere with certain lab tests (such as allergy skin testing), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

Keep all medical and lab appointments.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: severe drowsiness. In children, mental/mood changes (such as restlessness, irritability) may occur before drowsiness.