Zirtek allergy relief tablets contain the active ingredient cetirizine, which is a type of medicine called a non-sedating antihistamine. Cetirizine works by preventing the actions of histamine.
Pharmacist - M.B.A. (Public Health) D.I.C.
How does Zirtek work? Zirtek allergy relief…
How does Zirtek work?
- Zirtek allergy relief tablets contain the active ingredient cetirizine, which is a type of medicine called a non-sedating antihistamine. (NB: cetirizine is also available without a brand name, ie as the generic medicine.) Zirtek works by preventing the actions of histamine.
- Histamine is a substance produced by the body as part of its defence mechanisms. It is stored in cells called mast cells, in almost all tissues of the body. When the body reacts to a foreign substance (known as an allergen, eg flower pollen), the mast cells are stimulated by the allergen and release their stores of histamine.
- The released histamine then binds to its receptors (H1 receptors), causing a chain reaction that results in allergic symptoms. It causes an increase in blood flow to the area of the allergy, and the release of other chemicals that add to the allergic response.
- All this results in the symptoms of an allergic reaction. In hayfever, histamine causes inflammation of the nose, eyes, skin or airways and results in itchy watery eyes, a runny nose, sneezing and nasal congestion.
- Zirtek works by blocking histamine H1 receptors. It does not prevent the actual release of histamine from mast cells, but prevents it binding to its receptors. This in turn prevents the release of other allergy chemicals and reduces the blood supply to the area, providing relief from the typical symptoms of hayfever.
- Zirtek can also be used to relieve the symptoms of a condition called chronic idiopathic urticaria. This is a chronic itchy rash, similar to nettle rash, but with no apparent cause. Blocking the actions of histamine relieves the itching and reduces the rash associated with this condition.
- Zirtek is called a non-sedating antihistamine as it does not enter the brain, and is therefore unlikely to cause drowsiness. However, some people may experience some slight drowsiness.
What is Zirtek used for?
- Hayfever (seasonal allergic rhinitis) in adults and children aged six years and over.
- Inflammation of the nasal lining due to allergies that occur thoughout the year (perennial allergic rhinitis) in adults and children aged six years and over.
- Ongoing itchy rash with no known cause (chronic idiopathic urticaria) in adults and children aged six years and over.
How do I take Zirtek?
- Adults and adolescents over 12 years of age should take one tablet once a day.
- Children aged from 6 to 12 years should be given half a tablet twice a day.
- The tablets should be swallowed with a drink. They can be taken either with or without food.
- If symptoms persist despite treatment, seek medical advice from your doctor or pharmacist.
Use with caution in
- People with decreased kidney function. You may need a lower dose of this medicine if you have kidney problems. Ask your doctor or pharmacist for advice.
Not to be used in
- Children under six years of age. (Liquid forms of Zirtek are available from pharmacies for younger children).
- People with severe kidney failure requiring dialysis.
- As the tablets contain lactose they should not be taken by people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.
- This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
- If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
- Dry mouth.
- Stomach or intestinal discomfort.
- Pins and needles sensations.
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How to store Zirtek
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
If you have any more questions please ask your Pharmacist.
Remember to keep all medicines out of reach of children
Please Note: We have made every effort to ensure that the content of this information sheet is correct at time of publish, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.