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- What is cetirizine, and how does it work (mechanism of action)?
- What brand names are available for cetirizine?
- Is cetirizine available as a generic drug?
- Do I need a prescription for cetirizine?
- What are the side effects of cetirizine?
- What is the dosage for cetirizine?
- Which drugs or supplements interact with cetirizine?
- Is cetirizine safe to take if I'm pregnant or breastfeeding?
- What else should I know about cetirizine?
What is cetirizine, and how does it work (mechanism of action)?
Cetirizine is a non-sedating antihistamine that works by blocking histamine (H-1) receptors on cells. It is similar to the other second generation antihistamines loratadine (Claritin), fexofenadine (Allegra) and azelastine (Astelin). Histamine is a chemical that is responsible for many of the signs and symptoms of allergic reactions, for example, swelling of the lining of the nose, sneezing, and itchy eyes. Histamine is released from histamine-storing cells (mast cells) and then attaches to other cells that have receptors for histamine. The attachment of the histamine to the receptors causes the cells to be "activated," releasing other chemicals that produce the effects that we associate with allergy, for example, sneezing. Certirizine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of H1 receptor-containing cells by histamine. Unlike the first generation antihistamines, cetirizine and other second-generation antihistamines do not readily enter the brain from the blood, and, therefore, they cause less drowsiness. Cetirizine may cause more drowsiness than other second generation antihistamines. The FDA approved cetirizine in September 1996.
What are the side effects of cetirizine?
Side effects that have been reported with cetirizine include:
- sleepiness (occurs in 14% of patients),
- dry mouth,
- jitteriness, and
- sore throat.
Other important but rare side effects include:
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What is the dosage for cetirizine?
The recommended dose is 5 to 10 mg daily depending on the severity of symptoms.
Which drugs or supplements interact with cetirizine?
Theophylline (Theo-Dur, Respbid, Slo-Bid, Theo-24, Theolair, Uniphyl, Slo-Phyllin)reduces the breakdown of cetirizine by 16% and can increase blood levels of cetirizine. Drugs that cause drowsiness may add to drowsiness resulting from cetirizine.
Is cetirizine safe to take if I'm pregnant or breastfeeding?
Cetirizine has not been adequately evaluated in pregnant women. Available evidence suggests that risk to the developing fetus is low.
Cetirizine is excreted in human breast milk.
What else should I know about cetirizine?
What preparations of cetirizine are available?
Tablets: 5 and 10 mg. Tablets (Chewable or orally disintegrating): 10 mg. Syrup: 5 mg/5 ml.
How should I keep cetirizine stored?
Cetirizine should be stored in a dry place at 15 C to 30 C (59 F to 86 F).
Cetirizine (Zyrtec, Zyrtec Allergy, Zyrtec Hives) is a drug prescribed to treat seasonal or perennial allergies and hives. Side effects, drug interactions, dosing, and pregnancy safety information should be reviewed prior to taking this medication.
Multimedia: Slideshows, Images & Quizzes
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Hives (Urticaria & Angioedema)
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Chronic Rhinitis and Post-Nasal Drip (Symptoms, Treatment)
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Treatment & Diagnosis
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Medications & Supplements
- fexofenadine, Allegra, Allegra Allergy, Allegra Hives, Children's Allegra, Mucinex Allergy
- loratadine, Claritin, Claritin RediTabs, Alavert, Claritin Hives Relief, Children's Claritin
- loratadine and pseudoephedrine (Alavert Allergy & Sinus, Claritin-D, Claritin-D 24 hour)
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Prevention & Wellness
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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Top cetirizine Related Articles
Allergic CascadeThe allergic cascade refers to allergic reactions that happen in the body in response to allergens. A variety of immune cells and chemical messengers participate in the allergic cascade. Symptoms of the allergic cascade range from mild swelling and itching to full-blown anaphylactic shock. Allergen avoidance and medications are used to prevent or treat allergies.
AllergyAn allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. When these allergens come in contact with the body, it causes the immune system to develop an allergic reaction in people who are allergic to it. It is estimated that 50 million North Americans are affected by allergic conditions. The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Common allergic disorders include hay fever, asthma, allergic eyes, allergic eczema, hives, and allergic shock.
Allergy Treatment Begins At HomeAvoiding allergy triggers at home is one of the best ways to prevent allergy symptoms. Controlling temperature, humidity, and ventilation are a few ways to allergy-proof the home. Cleaning, vacuuming, and using HEPA air filters also helps control allergies.
Are Hives (Urticaria) ContagiousHives are not contagious are triggered by an allergic response to a substance. Symptoms and signs of hives include a raised, itchy red rash on the skin. An individual should seek medical care for hives if he or she develops dysphagia, wheezing, shortness of breath, or throat tightening.
Chronic rhinitis and post-nasal drip symptoms include an itchy, runny nose, sneezing, itchy ears, eyes, and throat. Seasonal allergic rhinitis (also called hay fever) usually is caused by pollen in the air. Perennial allergic rhinitis is a type of chronic rhinitis and is a year-round problem, often caused by indoor allergens, such as dust, animal dander, and pollens that may exist at the time. Treatment of chronic rhinitis and post nasal drip are dependent upon the type of rhinitis condition.
Drugs: What You Should Know About Your DrugsImportant information about your drugs should be reviewed prior to taking any prescription drug. Side effects, drug interactions, warnings and precauctions, dosage, what the drug is used for, what to do if you miss a dose, how the drug is to be stored, and generic vs. brand names.
Eye AllergyEye allergy (or allergic eye disease) are typically associated with hay fever and atopic dermatitis. Medications and cosmetics may cause eye allergies. Allergic eye conditions include allergic conjunctivitis, conjunctivitis with atopic dermatitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. Dry eye, tear-duct obstruction, and conjunctivitis due to infection are frequently confused with eye allergies. Eye allergies may be treated with topical antihistamines, decongestants, topical mast-cell stabilizers, topical anti-inflammatory drugs, systemic medications, and allergy shots.
fexofenadineFexofenadine (Allegra, Allegra Allergy, Children's Allegra, Allergy 24-HR, Mucinex Allergy) is a medication prescribed for the treatment of allergy and hives. Side effects, drug interactions, and pregnancy safety should be reviewed prior to taking this medication.
fexofenadine and pseudoephedrinefexofenadine and pseudoephedrine (Allegra-D) is a medication prescribed for the temporary relief of sneezing, runny nose, and nasal stuffiness from the common cold. Allegra-D is also prescribed for the relief of the symptoms of allergic conditions such as hay fever. Allegra-D may also be prescribed for the use in bronchitis, sore throat, and sinusitis. Side effects, drug interactions, and pregnancy safety should be reviewed prior to taking this medication.
Hay FeverHay fever (allergic rhinitis) is an irritation of the nose caused by pollen and is associated with the following allergic symptoms: nasal congestion, runny nose, sneezing, eye and nose itching, and tearing eyes. Avoidance of known allergens is the recommended treatment, but if this is not possible, antihistamines, decongestants, and nasal sprays may help alleviate symptoms.
HivesHives, also called urticaria, is a raised, itchy area of skin that is usually a sign of an allergic reaction. The allergy may be to food or medications, but usually the cause of the allergy (the allergen) is unknown.
How to Stop Coughing
Coughing is a reflex that helps a person clear their airways of irritants. There are many causes of an excessive or severe cough including irritants like cigarette and secondhand smoke, pollution, air fresheners, medications like beta blockers and ACE inhibitors, the common cold, GERD, lung cancer, and heart disease.
Natural and home remedies to help cure and soothe a cough include stay hydrated, gargle saltwater, use cough drops or lozenges, use herbs and supplements like ginger, mint, licorice, and slippery elm, and don't smoke.
Over-the-counter products (OTC)to cure and soothe a cough include cough suppressants and expectorants, and anti-reflux drugs.
Prescription drugs that help cure a cough include narcotic medications, antibiotics, inhaled steroids, and anti-reflux drugs like proton pump inhibitors or PPIs, for example, omeprazole (Prilosec), rabeprazole (Aciphex), and pantoprazole (Protonix).
Indoor AllergensIndoor allergens are substances that can cause an allergic reaction in some people. Common sources of indoor allergens include dust mites, cockroaches, molds, pets, and plants. Avoiding indoor allergens is one way to reduce allergy and asthma symptoms.
loratadineLoratadine (Claritin, Claritin RediTabs, Alavert, Claritin Hives Relief, Children's Claritin, and others) is drug prescribed for the treatment of the symptoms of non-nasal and nasal seasonal allergic rhinitis and hives (urticaria or allergic skin rash). Drug interactions, dosing, and side effects are discussed in the information.
loratadine and pseudoephedrineLoratadine and pseudoephedrine (Alavert Allergy & Sinus, Claritin-D, Claritin-D 24 hour, and many others) is a combination of two drugs used to temporarliy relieve a runny nose, sneezing, and nasal stuffiness from a common cold. It also is used to relive nasal and non-nasal symptoms of a variety of allergic conditions like seasonal allergic rhinitis. Side effects, drug interactions, dosing and storage, and pregnancy safety should be reviewed prior to taking this medication.
Urticaria PictureThis is a close-up view of wheals with white-to-light-pink color centrally and peripheral erythema. See a picture of Urticaria and learn more about the health topic.