Cetirizine: Indications, Administration, Side Effects, Precautions, Warnings and Interactions

It is an antihistamine medication that relieves the symptoms of allergies.


It is used to treat hay fever, allergic conjunctivitis (red and itchy eyes), eczema and urticaria . It is also used for reactions to insect bites and stings and for some food allergies .

Cetirizine is known as a non-numbing antihistamine . It is much less likely to make you sleepy than other antihistamines.

If you have symptoms throughout the year or seasonal allergies such as hay fever, your doctor may recommend Cetirizine. Because it can help relieve these allergy symptoms, but it does not prevent them.

This medicine blocks the effects of histamine. When it comes in contact with allergens, your body produces a chemical called histamine.

Histamine causes most symptoms related to allergic reactions.

Cetirizine is an allergy medication that can be bought without a prescription at a pharmacy. The medicine comes in capsules, tablets and a syrup. It is usually taken only once a day and starts to work quickly.

Cetirizine helps relieve mild to moderate allergy symptoms, such as:

  • Sneezing
  • Runny nose.
  • Itchy or watery eyes.
  • Itching in the throat or nose.

These reactions can occur after touching or inhaling allergens such as plant pollen, mold or pet dander. Allergies usually affect the nose, sinuses, throat and other areas of your upper respiratory system.

Cetirizine also helps relieve hives. They are itchy skin rashes. Hives often occur with food allergies or medications.

Administration and dosage

If you or your child has been prescribed Cetirizine, follow your doctor’s instructions about how and when to take it. If you bought Cetirizine at a pharmacy or store, follow the instructions that come with the package.

It comes in the form of tablets and capsules (10 mg) and as a liquid medicine (labeled as 5 mg / ml or 1 mg / 1 ml).

The usual dose in adults is 10 mg once a day.

Note: Doses are usually lower for people with kidney problems.

For children, the doctor will use weight or age to calculate the correct dose. If you bought Cetirizine for a child, follow the package instructions.

Depending on their age, children can take Cetirizine twice a day. In this case, try to space the doses with a separation of 10 to 12 hours.

It is usual to take this drug once a day. Children sometimes take it twice a day.

Cetirizine is classified as a non-sleepy antihistamine , but some people still feel that it makes them sleepy.

Adults and children 2 years and older can take the syrup, which is fruity. But adults and children 6 years and older should take the capsules and tablets.

The usual dose for adults under 65 and children over 6 is a dose of 10 milligrams (mg) per day. You should not take more than 10 mg in 24 hours.

Your doctor may recommend a dose of 5 mg once or twice a day if your allergies are mild.

How to take it?

It is correct to take Cetirizine with or without food.

Always take Cetirizine tablets or capsules with a drink of water, milk or juice. Tráguese whole. Do not chew them.

Cetirizine liquid may be easier for children to take than tablets or capsules. The liquid medication will come with a syringe or plastic spoon to help you measure the correct dose.

If you do not have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon since it will not give the correct amount.

When to take it?

You may only need to take Cetirizine the day you have symptoms, for example, if you were exposed to a trigger like an animal’s hair.

Or you may need to take it regularly to prevent symptoms, such as stopping hay fever during the spring and summer.

Ask your doctor about the dose for people who:

  1. They are 2 to 6 years old.
  2. They are over 65 years old.
  3. They have liver or kidney disease.

Side effects

Cetirizine is a new and second generation antihistamine. Unlike first-generation antihistamines, Cetirizine is less likely to cause side effects such as dangerous drowsiness, dry mouth, blurred vision, and overheating.

Common side effects:

Common side effects of Cetirizine occur in more than 1 in 100 people. Talk to your doctor or pharmacist if these side effects bother you or do not go away:

  • Stomachache.
  • Sore throat.
  • Headache.
  • Dizziness
  • Diarrhea.
  • Dry mouth.
  • Discomfort.
  • Stomach ache.
  • Feeling sleepy and tired
  • Feel dizzy.
  • Itching or rash
  • Tingling in the hands and feet.
  • Feeling agitated

Children are more likely to have diarrhea or nose symptoms similar to those of the cold than adults.

It is best not to drink alcohol while taking Cetirizine, as it can make you feel sleepy.

Serious side effects:

It is rare to have a serious side effect with Cetirizine, but tell your doctor immediately if you have:

  • Bruising or bleeding that is more than normal.

Serious allergic reaction:

In rare cases, it is possible to have a severe allergic reaction to Cetirizine.

A severe allergic reaction is an emergency. Contact a doctor immediately if you think you or someone around you is having a severe allergic reaction.

The warning signs of a severe allergic reaction are:

  • Contract a skin rash that may include itching, redness, swelling, blistering or peeling skin.
  • Wheezing
  • Oppression in the chest or throat.
  • Have trouble breathing or talking.
  • Swelling of the mouth, face, lips, tongue or throat.

How to deal with side effects?

What to do with:

Feeling drowsy: try a different antihistamine without drowsiness. If this does not help, talk to your doctor.

Feeling sick: stick to simple meals and do not eat fatty or spicy foods.

Headache: take analgesics every day, such as acetaminophen or ibuprofen.

Dry mouth: chewing gum without sugar or sucking sugar free sweets.

Diarrhea: Drink plenty of water in small, frequent sips. It can also help to take oral rehydration solutions. You can buy them at a pharmacy or supermarket to avoid dehydration.

Precautions and warnings

In general, Cetirizine is a safe and effective medication, but certain warnings and precautions should be taken into account when taking it.

Be careful when using machinery:

Although Cetirizine does not usually cause drowsiness, some people respond differently when they take it, especially in the first doses.

Be careful not to drive your car or use machinery until you know for certain how your body will respond to Cetirizine.

Check the ingredients:

Try not to use Cetirizine if you have ever had an allergic reaction to it or any of its ingredients. Also, stay away if you are allergic to any antihistamine that contains hydroxyzine.

Do not use during pregnancy and lactation:

Talk to your doctor before taking Cetirizine if you are pregnant or plan to become pregnant. Generally, it is not recommended to take Cetirizine during pregnancy.

It is also not recommended if you are breastfeeding. This is because the medication passes into breast milk.

Talk to your doctor if:

  • Have a liver or kidney disease.

Your doctor can tell you that Cetirizine is not for you if you have any of these conditions:

  • Heart disease.
  • Thyroid disease
  • Diabetes.
  • Glaucoma.
  • High blood pressure
  • Enlarged prostate with urinary retention.

Cetirizine is an over-the-counter medication that can relieve the symptoms of mild to moderate allergy. Like any medication, especially over-the-counter medications, you should understand all the considerations before you start taking it.

Interactions with other medications

There may be interaction with the following medications and supplements:

  • Midodrine, a medicine used to treat low blood pressure.
  • Ritonavir, a medicine used to treat HIV infection.
  • Any medication that makes you feel sleepy, gives you a dry mouth or makes it hard to urinate. Taking Cetirizine could make these side effects worse.
  • Mix Cetirizine with herbal remedies and supplements. There may be a problem when taking some herbal remedies and supplements along with Cetirizine, especially those that cause drowsiness, dry mouth or make it difficult to urinate.

Tell your doctor or pharmacist if you are taking other medicines, including herbal remedies, vitamins or supplements.

Pregnancy and lactation:

You can take Cetirizine while you are pregnant. However, a similar antihistamine called Loratadine is usually used first because there is more information to say that it is safe.

It is not believed that Cetirizine is harmful during pregnancy, but as it has been studied to very few pregnant women, it is not possible to be sure.

Cetirizine and lactation:

It is generally safe to take Cetirizine if you are breastfeeding, as only a small amount enters breast milk.

However, talk to your doctor before taking Cetirizine if your baby is premature, has low birth weight or has other health problems.

Cetirizine does interact with other substances. For example, avoid consuming alcoholic beverages while taking Cetirizine. Doing it can be dangerous. Mixing this drug with alcohol can make you drowsy or less alert.

If you take any type of tranquilizer, sedative or sleep aid, be sure to consult your doctor before using Cetirizine.

Mixing it with medications that depress the central nervous system can amplify sedation. It can further damage your mental and nervous system functions.

There is a possibility of pharmacological interaction between Cetirizine and Theophylline. Theophylline is a drug that some people take with asthma and other lung problems.

However, the interaction is probably related to the dose. It was only reported with daily doses of theophylline of 400 mg or more. In these cases, Cetirizine took longer to leave the body.

There may be an interaction between Cetirizine and any of the following:

  • Abiraterone acetate.
  • Acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine).
  • Aclidinio.
  • Alcohol.
  • Amphetamines (dextroamphetamine, lisdexamphetamine).
  • Other antihistamines (diphenhydramine, chlorpheniramine, hydroxyzine).
  • Antipsychotics (chlorpromazine, clozapine, haloperidol, olanzapine , quetiapine, risperidone ).
  • Aripiprazole.
  • Atorvastatin.
  • Atropine.
  • Azelastina.
  • Antifungals “azoles” (fluconazole, ketoconazole, voriconazole).
  • Baclofeno.
  • Barbiturates (butalbital, pentobarbital, phenobarbital).
  • Benzodiazepinas (lorazepam, diazepam)
  • Belladona.
  • Benztropina.
  • Betahistina.
  • Brimonidina.
  • Buprenorphine
  • Buspirona.
  • Carvedilol.
  • Chloral hydrate.
  • Cyclosporine.
  • Dexamethasone .
  • Dipyridamole.
  • Disopyramide.
  • Doxorubicin .
  • Dronedarona.
  • Droperidol.
  • Efavirenz.
  • Flavoxate.
  • Grape juice.
  • Glucagon.
  • Glycopyrrolate.
  • Ipratropio.
  • Ketotifen.
  • Magnesium sulphate.
  • Mefloquina.
  • Muscle relaxants (baclofen, cyclobenzaprine, metocarbamol, orphenadrine).
  • Narcotic pain medications (codeine, fentanyl, oxycodone, morphine).
  • Potassium chloride.
  • Prazosin.
  • Progesterone.
  • Propranolol.
  • Quinidina.
  • Quinine
  • Reserpina.
  • Rifampin.
  • Ropinirol.
  • Grass of San Juan.
  • Scopolamine .
  • Secretina.
  • Medications for seizures (clobazam, ethosuximide, felbamate, levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide).
  • Selective serotonin reuptake inhibitors (citalopram, duloxetine, fluoxetine, paroxetine, sertraline).
  • Helpers to sleep ( zopiclona ).
  • Sodium oxybate
  • Diuretics Thiazide (water pills such as hydrochlorothiazide, indapamide, metolazone).
  • Tiotropio.
  • Tolterodina.
  • Tramadol.
  • Tricyclic antidepressants ( amitriptyline , clomipramine, desipramine, trimipramine).
  • Tyrosine kinase inhibitors (dabrafenib, imatinib, nilotinib, sunitinib).

Common considerations and questions

Who can and can not take Cetirizine?

Adults and children 6 years of age and older can take Cetirizine tablets and fluids that you buy at pharmacies and supermarkets.

Children older than 2 years can also take liquid Cetirizine for hay fever and skin allergies.

Cetirizine can also be taken under medical supervision by children older than 1 year.

Do not take this drug if:

  • You have had an allergic reaction to Cetirizine or any other medication in the past.
  • If you have an allergy to peanuts or soy.
  • If you have an allergy to food additives, such as E218 or E216.
  • Has an intolerance to, or can not absorb, some sugars such as lactose or sorbitol.
  • If you have liver or kidney failure.
  • You have epilepsy or another health problem that puts you at risk for attacks.
  • He has a disease that makes him more vulnerable to holding urine.

What happens if I forget to take the medication?

Take your missed dose as soon as you remember it, unless it is almost time for your next dose. Do not take a double dose to make up for it forgotten.

If you forget to give a dose to a child who is taking Cetirizine twice a day, you can give the dose if it is within 4 hours after the date they should have taken it.

If you remember more than 4 hours later, do not give the forgotten dose. Instead, wait until the next dose and continue as normal.

What happens if I take too much?

Cetirizine is generally very safe. It is unlikely that drinking too much will be harmful to you or your child.

If you take an extra dose by mistake, you can get some of the common side effects. If this happens or if you are worried, contact your doctor.

How does Cetirizine work?

Cetirizine is a medicine called antihistamine.

When you come into contact with something that you are allergic to, such as pollen, animal or fur hair, house dust or insect bites, your body produces a chemical called histamine.

Usually, histamine is a useful substance, but in an allergic reaction it causes unpleasant symptoms that include itching, watery eyes, runny or blocked nose, sneezing and skin rashes.

Cetirizine blocks the effects of histamine and reduces the symptoms mentioned.

When will I feel better?

You should start to feel better in an hour.

How long should I take Cetirizine?

You may only need to take it for a short time or as a single dose. For example, if you have a reaction to an insect bite, you may only need to take Cetirizine for a day or 2.

Is it safe to take Cetirizine for a long time?

You may need to take Cetirizine for a longer time if you take it to prevent symptoms, for example, to stop hay fever when the pollen level is high.

It is unlikely that Cetirizina will harm you if you take it for a long time. However, it is better to take Cetirizine only for as long as you need it.

Can I drink alcohol with Cetirizine?

It is best not to drink alcohol while taking Cetirizine, as it can make you feel sleepy.

Is there any food or drink I should avoid?

You can eat and drink normally while taking Cetirizine.

Can I drive or ride a bicycle when I take the medication?

This drug is classified as a non-numbed antihistamine, but it is still possible to feel sleepy after taking it.

If this happens to you, do not drive a car or ride a bicycle until you feel better.

What is the difference between Cetirizine and other antihistamines?

Cetirizine is known as a non-numbing antihistamine. This is because it is less likely to make you feel sleepy than others, called sedating antihistamines such as Piriton (chlorpheniramine).

Most people prefer to take a non-sleepy antihistamine instead of a sedative. An exception is when you want the medication to numb you, for example, if you have itchy skin that keeps you awake.

Can I take it with analgesics?

Yes, you can take Cetirizine together with paracetamol or ibuprofen.

Can I take Cetirizine with other treatments for hay fever?

Yes, it is okay to take Cetirizine along with other treatments for hay fever, for example nasal sprays with steroids (such as Beconase, Rhinacort Aqua and Flixonase Nasules) or eye drops.

Can I take Cetirizine in higher doses than in the package?

Your doctor may suggest that you or your child take a higher dose (up to 4 times the usual dose) in case of severe rash or angioedema (swelling under the skin).

However, taking high doses of Cetirizine is not suitable for everyone. Talk to your doctor if you think this drug is not working for you.

Will it affect my fertility?

There is no evidence that Cetirizine affects male or female fertility.

Will it affect my contraception?

Cetirizine does not affect any type of contraception, including the contraceptive pill and the morning after pill.

Can lifestyle changes alleviate hay fever?

It will help if you do not spend too much time outside if the pollen count is high.

Tips for when you are outside:

  1. Do not cut grass or walk on grass.
  2. Wear wraparound sunglasses to prevent pollen from entering your eyes.
  3. Put Vaseline around your nostrils to help catch the pollen.
  4. Shower and change clothes after being outside to wash pollen.

Tips for when you are inside:

  1. Keep windows and doors closed as much as possible.
  2. Vacuum regularly and sprinkle with a damp cloth.
  3. Do not keep fresh flowers in the house.

How does this medication work? What will he do for me?

Cetirizine belongs to the class of drugs called second generation antihistamines, specifically the class known as histamine receptor antagonists.

For adults and children 2 years of age and older, it is used to relieve symptoms associated with seasonal allergies, including sneezing, itchy nose and throat, stuffy and runny nose, and tearing, redness, or itchy eyes

It is also used to relieve symptoms associated with allergic skin conditions (such as: chronic idiopathic urticaria and itchy skin).

For adults and children over 12 years of age, it is also used to relieve symptoms associated with allergies throughout the year.

Cetirizine works by blocking the actions of one of the body’s natural chemicals known as histamine. Histamine is responsible for many of the symptoms caused by allergies.

Usually begins to relieve allergy symptoms in 20 minutes and lasts 24 hours.