Cetirizine

Cetirizine is one of the three everyday non-drowsy antihistamines, alongside loratadine and fexofenadine. All three do much the same job; people simply respond differently, and it is entirely normal for one to work for you when another does not.

What it is used for

Hay fever and other allergic rhinitis, allergic conjunctivitis, hives (urticaria), and itching from allergic reactions and some skin conditions. It also helps allergic reactions to insect bites and stings.

It does not help a blocked nose much — that responds far better to a steroid nasal spray. If congestion is your main problem, an antihistamine alone will disappoint you.

How to take it

Adults and children over 12 usually take 10mg once daily. Doses for younger children are lower and depend on age — follow the label or ask us.

It can be taken with or without food, at any time of day. Many people prefer the evening, since a small proportion feel slightly drowsy on it.

In hay fever season, taking it daily through the season works better than taking it only on bad days. Starting a couple of weeks before your usual trigger season helps further.

Drowsiness and side effects

Cetirizine is described as non-drowsy, and for most people it is — but it causes drowsiness slightly more often than loratadine or fexofenadine. If you feel sleepy on it, do not drive or use machinery, and consider switching.

Other common effects: dry mouth, headache, nausea, and occasionally stomach ache. These are usually mild.

Avoid alcohol while taking it if you notice any drowsiness.

Who should take care

• People with kidney problems may need a lower dose
• Anyone with epilepsy should check first
• Anyone with difficulty passing urine or an enlarged prostate should ask before use

Cetirizine can be used in pregnancy and while breastfeeding where an antihistamine is needed, though loratadine is often preferred in pregnancy — ask us. Stop antihistamines for a few days before allergy skin-prick testing, as they can mask results.

Frequently asked questions