Explanation

Cetirizine hydrochloride (also called Benadryl®, Piriteze® and Zirtek®) is a medicine used for treating an itchy, runny or blocked nose caused by hay fever and other allergies.

How does it work?

Cetirizine hydrochloride is a type of medicine called an anti-histamine. It works by blocking histamine - the chemical that causes the symptoms of allergies in your body.

What does it look like?

Cetirizine hydrochloride comes as a white tablet that you swallow with water or as a clear syrup that smells like banana.

When and how do I have to take it?

You should take your cetirizine hydrochloride either once a day in the morning or twice a day - once in the morning and once in the evening. It is important that you take your medicine exactly how your doctor has told you to.

But what if I don't feel like taking it?

Taking your cetirizine hydrochloride will help control the symptoms of your hay fever and allergies. If you don't take it, your symptoms may come back or get worse.

What should I do if I forget to take it?

If you forget to use your cetirizine hydrochloride, don't worry. Just take it as soon as you remember if it's not much later than you would normally take it. If it's close to the time you would take your next dose, then forget your missed dose and take the next dose as usual. BUT if you are taking the tablets you must wait at least 24 hours before taking another dose. If you are taking the syrup then continue taking your cetirizine hydrochloride as you have been told to.

Don't take twice as much to make up for the dose you missed. Remember the three Ds: Don't Double Dose!

What if I take too much?

It can be very dangerous if you take too much cetirizine hydrochloride. If you do take more than you have been told to make sure you tell your doctor or the adult looking after you, or go to the hospital and tell the doctors or nurses there. Take your medicine with you so they know what you have taken.

The things you might notice if you have taken too much are:

feeling very sleepy or falling unconscious

feeling very excited

headaches

shaking that you can't control

seeing or hearing things that aren't really there

seizures

feeling or being sick

What are the most likely side effects I might get?

Cetirizine hydrochloride can sometimes cause mild side effects while you are taking it. You might have some side effects, or you might not have any at all.

The most likely side effects are:

feeling sleepy

a headache

feeling dizzy

getting a dry mouth

having a sore stomach

Because you can get an extra dry mouth while you are taking cetirizine hydrochloride, you are more likely to get cavities. So, it's really important that you look after your teeth and remember to brush them every morning and every night.

If your side effects are bothering you, or your notice any others not listed here, tell your doctor or an adult who looks after you.

Are there any other side effects you haven't mentioned?

In some people, cetirizine hydrochloride can cause an allergic reaction, although this is unlikely. If you notice a rash on your skin, swelling in your face or mouth, or you have trouble breathing, stop taking it and tell your doctor or an adult looking after you straight away.

It is very unlikely but cetirizine hydrochloride can cause seizures. If you notice this or any other side effects, tell your doctor or an adult who looks after you about it straight away.

Is it safe for me to take cetirizine hydrochloride?

Before you start taking cetirizine hydrochloride, tell your doctor about any medical problems that you know you have, or have had in the past.

If you have ever had an allergic reaction to cetirizine hydrochloride before it could be dangerous if you start taking it. Tell your doctor so that he or she can choose another medicine to treat your hay fever.

It is especially important to tell your doctor if you have or have ever had liver or kidney problems. It may not be safe for you to take cetirizine hydrochloride if you have.

Is it okay for me to take cetirizine hydrochloride if I am already taking other medicines?

You should tell your doctor about any other medicines that you are taking, or have taken recently, including herbal medicines.

It is especially important for you to tell your doctor if you are taking CNS depressant medicines which are usually used to treat anxiety or sleeping problems.

What if I have other questions?

If you have any other questions, you can ask your doctor, or chat to other people about cetirizine hydrochloride in the Medikidz forums and virtual world, Mediland.