A-Z Classification
Educate yourself about the types of medication and what they do.
  • Classification A-D
  • Classification E-L
  • Classification M-Z
  • Allergy Medication

  •  Contact Us
  • Suggestions
  • Complaints
  • Help
  • Feedback Form

  • Useful numbers
    This link will open a popup window with a print button. Click to close the window.

    the Allergy Site Navigator
    You are in >  Zyrtec
    For Home  >  Home

    Product Name :   Cetirizine / Zyrtec, Known as Zyrtec in the United States and Canada
    Product Type :   Cetirizine Hydrochloride
    Manufacturer :   Pfizer
    Packaging and Product :   Packets of 30 Zyrtec 10 mg tablets

    What is Zyrtec?
    Zyrtec tablets are an anti-allergy remedy containing the active ingredient Cetirizine Hydrochloride 10mg.
    The most common form of allergy is hayfever, a seasonal disorder occurring during Spring and Summer caused by airborne pollens.
    Typical symptoms include sneezing, runny nose and itchy watery eyes.
    Other allergies are caused by eating certain foods, through contact with certain drugs or chemicals, or those caused by house dust mites or animal fur.
    These reactions are caused by an allergic reaction between the allergen and certain cells in the body.
    This reaction triggers the release of a number of chemical substances which irritate the body.
    One of these chemicals is histamine.
    There are a number of medicines available for treating allergies, the most common being antihistamines. Some antihistamines also counteract the effects of other irritating chemical substances as well as those of histamine.
    These are called anti-allergics.
    Zyrtec is an anti-allergic used to treat hayfever and other allergic reactions.
    It is fast acting (10-20 minutes) non-sedating and lasts for 24 hours.
    For children under 12 years, twice daily dosage is recommended because the effect of Zyrtec does not last as long in children.

    Cetirizine or Zyrtec is a non-sedating antihistamine. It is a metabolite of hydroxyzine, an sedating antihistamine.

    How It Works:
    Cetirizine or Zyrtec blocks histamine - specifically histamine 1 - sites. By blocking these sites histamine is not released and the effects of histamine on the body are not seen - runny nose, sneezing, watery eyes.

    Side Effects:
    While Cetirizine or Zyrtec is classified as a non sedating antihistamine, it is able to cause some sedation, but much less than other antihistamines. As well, it can cause dry mouth.

    Cautions for People:
    Because Cetirizine or Zyrtec does have the potential to cause some sedation, it should be carefully used in situations where alertness is required - driving a car.

    Drug Interactions:
    Cetirizine or Zyrtec has an additive effect with alcohol and thus should not be used with alcohol.
    Cetirizine or Zyrtec does not interact with antibiotics such as erythromycin to cause heart beat irregularities.

    Before taking Zyrtec:
    Pregnant or breast feeding women should consult a doctor before taking ZYRTEC. People with known hypersensitivity to ZYRTEC should AVOID taking it.
    People with kidney problems should seek medical advice before taking ZYRTEC, a smaller dose may be necessary.

    Zyrtec Dosage:

    Single daily dose of one table (Certizine 10mg)

    Children over 6 years of age
    Single daily dose of one table (Certizine 10mg) although this may need to be broken up into 2 individual dosages of half a tablet

    Children 2 to 6 years of age
    A single daily dose of 5mg or half a tablet although this may need to be taken as 2 individual dosages of a quarter tablet each.

    After Taking Zyrtec:
    Occasionally some effects may occur, such as feeling drowsy, dry mouthed or fatigued.
    These are usually mild and tend to wear off as treatment continues. Drowsiness occurs rarely, but if your feel drowsy after taking Zyrtec, be cautious about driving or using machinery for 8 hours.
    In such cases it is better to take your Zyrtec before you go to bed at night. If you have any concerns consult your medical practitioner.


    Back to the top

    Visit TAS
  • TAS Main Site
  • TAS Organic Shop
  • Allergy Forum
  • TAS Representative

  • Drug Classifications
    Allergy sufferers are often prescribed a host of different medications without the benefit of a proper explanation.
    Find out from this comprehensive list what your medication is for and how it works. Be an informed patient and remember that it's your health on the line.

    You have the right to question and every right to be answered. If these lists arouse an interest there are a few links below, you might also fancy having a look at.

  • Drugscope.co.uk
  • Drug Info Zone
  • Pharmweb

  •  Knowledge Bank
    Contribute your own tips, experience and literature. This link will open a feedback form to allow you to enter the information and upload it to us. Please include source as we cannot publish unsubstantiated info and must acknowledge copyright where relevant.