Cetirizine is a generic medication for the drug Zyrtec:

Cetirizine medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.

Cetirizine 10 mg
Cetirizine 20 mg

General Information

Cetirizine, often misspelled as Cetrizine, is an antihistamine used to counteract or alleviate the body's reaction to certain allergens. Once a medication that could only be obtained through a doctor's prescription, Cetirizine can now be purchased as an over-the-counter medication at almost any pharmacy and is more commonly known as Zyrtec® and Reactine.

When a person is exposed to certain allergens, such as various pollens emitted by specific grasses and plants, or to animal dander, insect bites, dust mites, molds, metals, etc., the body releases histamines. Though there is always some histamine level in the human body, when an allergen is encountered the histamine level can and often does increase dramatically. Due to the higher histamine levels the body's reactions can include symptoms such as a runny nose, red, watery, itchy eyes, sneezing, coughing, and even rashes. In order to then combat the irritations caused by the newly elevated histamine levels, an antihistamine is taken. The antihistamine, such as Cetirizine, then only controls the symptoms, it does not cure the body from having a reoccurring reaction to the offending allergen.

How Does Cetirizine Work?

When the body encounters an allergen, histamines are released. A histamine is a chemical that seeks out and finds certain receptors on body cells that are located mainly in the nose and throat. The histamine then binds to those receptors causing the cells to leak fluids and swell up. An antihistamine such as Cetirizine then searches for the same receptors and provides them with a cover or a coating. This coating then prevents the histamine from being able to bind to the receptors and eliminates or reduces any irritation.

When/How is Cetirizine Taken/Used/Applied?

Cetirizine can be taken in several forms that include tablets, chewable tablets, and syrup. If you know in advance that you will be exposed to a known allergen, taking Cetirizine two to five hours before the exposure occurs can greatly reduce and even prevent the body's reaction to the allergen. If, however, you have already been exposed, take only the correct prescribed dose of medicine. You can then expect to experience some alleviating results in as little as fifteen to thirty minutes with full alleviation realized in about one to two hours.

Side Effects of Cetirizine

As with all medications, certain side effects can result from taking Cetirizine though the side effects reported for this medication tend to be rather mild. Among some of the basic side effects that may occur with this antihistamine include dizziness, drowsiness, headaches, diarrhea, dry mouth, insomnia, nosebleeds, and abdominal pain. In more serious cases difficulty in swallowing and breathing has occurred.

Other Brand Names

Cetirizine can be more commonly found under the brand names Zyrtec® and Reactine. The Zyrtec® medications also include:

  • Zyrtec-D
  • Zyrtec Chewable
  • Zyrtec Hives Relief
  • Zyrtec Syrup

Safety Information:

Before taking any new medications it is always extremely important that you speak with your doctor and your pharmacist about any other medications that you may be taking at that time as medications can adversely interact with each other causing severe harm. Even though Cetirizine (Zyrtec®) can be obtained over-the-counter, you should take the time to get advice from the local pharmacist. If you are pregnant or breast-feeding or if you have kidney or liver disease you should not take Cetirizine. Consult with you doctor for a proper medication to take. Cetirizine is also not recommended for children under the age of two.


When taking Cetirizine (Zyrtec), always follow the prescribed dosage on the package label. In general, the following is a list of dosage levels that should be observed:

Adults and Older Children: 5mg tablet - once daily for mild symptoms
10mg tablet - once daily for moderate symptoms

Adults 65 years of age and older: Consult with a physician for proper dose.

Children ages 2 through 5: 2.5mg chewable tablets - once daily
2.5ml syrup (1/2 teaspoon) - once daily

Visual Description:

Cetirizine (Zyrtec) tablets come in the shape of a rounded off rectangle. They are white and have a smooth light film coating on the surface to make swallowing easier. They can be found in 5mg and 10mg strengths.

The Cetirizine (Zyrtec) chewable tablets are round and also can be found in 5mg and 10mg strengths. They are purple in color with a grape flavoring making it more easily taken by children and those who have difficulty swallowing.

The Cetirizine (Zyrtec) syrup comes in both grape and banana flavoring. The syrup itself can be colorless in some instances to a rather very light shade of yellow in other. The syrup version is recommended for children five and under in age.