Cetirizine

What is Cetirizine?

Cetirizine is an antihistamine which treats symptoms caused by allergies. It is used to treat hayfever, insect bites or stings, allergic conjunctivitis, eczema and hives. Cetirizine is a medicine that is taken as a tablet or liquid to help resolve an allergic reaction.

How does Cetirizine work?

Cetirizine is an antihistamine that stops the action of histamine. Histamine is a chemical produced by your body when you come into contact with something you are allergic to. Histamine triggers symptoms we collectively call an “allergic reaction”, for example, a blocked or runny nose, sneezing, itchy eyes or skin.

How long does Cetirizine take to work?

Cetirizine should start to work within an hour after taking it.

How to take Cetirizine?

Always follow the instructions given by your doctor on how to take Cetirizine. Swallow tablets whole with water or juice. If you are using the liquid version, use the provided measuring spoon to measure the correct dose. For hay fever, you may need to take Cetirizine every day to prevent symptoms from occurring. Otherwise, you can take Cetirizine when you need it, for example, when you have an allergic reaction.

Cetirizine dosage

Cetirizine is available as 10 mg tablets. A 5 mg per 5 ml dose is available in liquid form, which can be used by adults and children over six years old.

Cetirizine side effects

Common side effects that are associated with taking Cetrizine are: 

• Drowsiness
• Headaches
• Nausea
• Stomach pain
• Dry mouth
• Blocked or runny nose (similar to having a cold)
• Agitation
• A tingling feeling in your hands and feet
• Diarrhoea 
• A rash or itchy skin 

If you experience any severe side effects, or the symptoms of an allergic reaction (e.g. hives, itching, breathing difficulties, swelling), you should seek immediate emergency medical attention.

Contraindications

Cetirizine can usually be taken by adults and children over the age of six years old. However, you shouldn’t take Cetirizine if:

• You are allergic to cetirizine or have experienced an allergic reaction to similar medicines to cetirizine in the past
• You are allergic to peanuts, soya, E218 or E216
• You have an intolerance to lactose or sorbitol
• You have kidney or liver failure
• You suffer from epilepsy or seizures 
• You have difficulty urinating 
• You have a scheduled allergy test, as Cetirizine can interfere with the results

Drug interactions

Inform your doctor or pharmacist if you are taking any other medicines before you start Cetirizine. The following medicines may interact with Cetirizine:

• Midodrine - which is taken for high blood pressure
• Ritonavir - which is an antiretroviral treatment for HIV
• Other medicines that have a drowsy effect or cause urination problems, including herbal remedies

Is Cetirizine non-drowsy?

Cetirizine can make you feel tired or sleepy. Some people may experience drowsiness as a side effect of Cetirizine. Therefore, you should avoid driving or operating machinery whilst taking Cetirizine if it makes you sleepy. You should speak to your doctor about alternative treatments.

Cetirizine and alcohol

Avoid drinking alcohol while taking Cetirizine as it can increase your chances of becoming drowsy, sleepy and feeling tired.

Cetirizine and pregnancy

Speak to your doctor if you are pregnant or planning a pregnancy before using Cetirizine.

Can I drive after taking Cetirizine?

Cetirizine can make some people feel sleepy or tired. Tiredness may affect your reflexes when driving. You should avoid driving while taking Cetirizine or wait and see how Cetirizine affects you before driving.

Will Cetirizine affect my fertility?

Antihistamine medicines such as Cetirizine are unlikely to affect your fertility. If you are trying to get pregnant, then consult your doctor before taking Cetirizine.

Will Cetirizine interfere with my contraception?

Your contraception is unlikely to be affected by Cetirizine. This includes all methods of hormonal contraception. However, you should always inform your doctor of any other medicines you take before taking Cetirizine.

Can I take Cetirizine with pain killers?

You can take Cetirizine alongside some painkillers. If you are taking painkillers, you should check with your doctor before taking cetirizine. Some painkillers cause constipation, and Cetirizine can cause dehydration which can make constipation worse. Check with a pharmacist to find a painkiller that’s suitable to take alongside Cetirizine.

How to cope with Cetirizine side effects?

Avoiding excess alcohol and drinking enough water can help to manage headaches and a dry mouth. Sit still or lie down if you experience dizziness and avoid driving or operating machinery until this passes. If Cetirizine makes you sleepy, then take it at night before bed.

How to avoid hay fever?

The effects of hay fever can be reduced by taking some simple precautions. You could try staying indoors on days that have a high pollen count. You could also try walking on freshly cut grass. Wear wraparound sunglasses to protect your eyes from pollen. Get into the habit of washing and changing your clothes after being outside. Avoid having freshly cut flowers inside your home and keep the windows closed.

Prescription vs over the counter Cetirizine

Cetrizine is available on prescription, and you can purchase it over the counter in a pharmacy. If you choose to get it on prescription, then your doctor can recommend the most suitable dose for your symptoms. Prescriptions are particularly important for children as your doctor needs to calculate the right dose for them to take.

Cetirizine vs other antihistamines

Cetirizine may be preferred to other traditional antihistamines as it is less likely to cause drowsiness or sleepiness. Loratadine is another antihistamine medicine that is less likely to make you feel sleepy. Fexofenadine is an antihistamine that can be used if Cetirizine or Loratadine is not effective. However, Fexofenadine must be prescribed by a doctor.

Can I take Cetirizine with other antihistamines?

You should always take Cetirizine as instructed by your doctor or pharmacist. They may suggest you take more than one type of antihistamine to keep your symptoms under control. You should only do this if your doctor has prescribed it.

Are there any other uses for Cetirizine?

Cetirizine can also be used to relieve eczema, allergic conjunctivitis, hives and insect bites or stings.

Is long term use of Cetirizine safe?

You should only take Cetirizine when you have symptoms. If you are planning to use Cetirizine all the time or want to use it long term, then speak to your doctor so that they can assess your symptoms. They will suggest the most appropriate treatment.

Can Cetirizine be used for any other allergies?

Cetirizine is mainly used to treat hay fever. But if you suffer from eczema, allergic conjunctivitis or hives, Cetirizine can provide relief. Cetirizine can also treat itching and swelling caused by an insect bite or sting.

Can Cetirizine be used for a cold?

Cetirizine is for treating the symptoms produced by an allergy. Even if these are similar to the symptoms of a cold, this medicine is not suitable for treating the cold virus.

Will Cetirizine help me sleep?

Cetirizine can make you feel sleepy, but this doesn’t happen with everyone. However, if your symptoms prevent you from falling asleep, such as a blocked nose, then Cetirizine may help relieve this and allow you to breathe easier.

Is Cetirizine addictive?

Cetirizine is not known to be addictive. 

Active ingredients

Cetirizine hydrochloride is the active ingredient in this antihistamine treatment.

Inactive ingredients

The other ingredients in Cetirizine are: lactose, microcrystalline cellulose, maize starch, colloidal anhydrous silica, magnesium stearate, talc, hypromellose, titanium dioxide (E171), macrogol4000 and sodium citrate.

Please note: Different brands of generic Cetirizine may contain different inactive ingredients. Please check the patient information leaflet provided for details.

Which ingredients can cause an allergic reaction?

Unless you have a known sensitivity to the active or inactive ingredients, a severe allergic reaction to this medication is rare and uncommon. Here are some symptoms you should look out for: rash, facial swelling, dizziness, chest tightness, and trouble breathing. It is important to seek immediate medical attention if you notice any of these symptoms after taking the medication as it is an emergency and can be life-threatening.