Cetirizine is a type of anti-histamine which is often used for hayfever, allergies and allergy related skin reactions. It is available to purchase over the counter from most pharmacies and is also available on prescription.

Cetirizine is used to treat the symptoms of hayfever and skin reactions associated to allergy (hives). It is particularly helpful to reduce the sensation of itching in the skin or eyes and also helps to reduce sneezing and runny nose associated with hayfever.

Antihistamines mainly work against chemicals in the body called histamines. These are produced in response to injury or inflammation of the cells in the body. In allergic conditions such as hayfever, these histamines are unnecessarily produced and give rise to symptoms such as sneezing and itchy eyes.

Antihistamines start to work in 30 minutes reaching maximum effect after 1-2 hours.

Your doctor will advise on the correct dose for you. The dose advised on the packaging of the cetirizine you can buy will usually be 10mg once a day for adults. Your doctor may prescribe a higher dose. Tablet and liquid forms are available.

As some people are more sensitive to the side effects it may be best to avoid operating heavy machinery or driving.

Avoid drinking alcohol when taking cetirizine.

Avoid taking cetirizine with alcohol as this can increase the likelihood of experiencing the side effects of tiredness and fatigue.

There is no evidence of harm from taking cetirizine during pregnancy, however the evidence is very limited so speak to a doctor before taking this, especially early in pregnancy.

Antihistamines are present in breast milk but they are not known to be harmful.

They are generally best avoided if breastfeeding but your doctor can discuss with you whether the benefits outweigh the risks.