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Cetirizine vs Loratadine for Effective Hay Fever Relief

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The main differences between Cetirizine and Loratadine are how quickly they work and the type of side effects that you may experience.
Cetirizine tablets tend to work slightly faster than Loratadine, but are more likely to make you feel sleepy. Both medications are taken daily, relieving symptoms for 24 hours, and are proven to be safe and effective in treating hay fever and allergy symptoms.
This detailed overview explains the key differences between Cetirizine and Loratadine so you can confidently manage your symptoms at home.

 

Key Facts & Findings

  • Cetirizine (Zyrtec) works in as little as 20 minutes, but may make you feel drowsier than Loratadine. 
  • Loratadine (Claritin) is considered one of the least sedating antihistamines, ideal if you need to stay alert throughout the day. 
  • If you’re prone to stronger allergy symptoms, Cetirizine may be a better choice.  
  • Always check your suitability before taking cetirizine or loratadine, particularly if you are pregnant, have liver issues, or drink alcohol.  

Cetirizine vs Loratadine: An Overview

 

Factor Cetirizine Loratadine
Time it takes to work 20 - 60 minutes 1 - 3 hours
How long it lasts for 24 hours 24 hours
Drowsiness risk Low Low
Adult dosage 1 tablet daily 1 tablet daily
Most common side effects Diarrhoea, dry mouth, drowsiness, fatigue Headache, drowsiness, trouble sleeping, increase in appetite, nausea
Can it be used long-term? Unlikely to cause harm long-term Unlikely to cause harm long-term
Does it interact with other medicines? Yes Yes

 

Cetirizine vs Loratadine: How Effective are They?

Cetirizine

  • Works fast – relief in around 20 to 60 minutes 
  • Treats hay fever symptoms, such as sneezing, watery eyes, runny nose and itching.   
  • Can also be used for itchy skin conditions caused by allergic reactions, including hives and eczema

Loratadine

  • Effectively blocks histamine for around 24 hours  
  • Safe to use long-term with no known side effects  
  • Calms itchy skin from eczema, insect bites and heat rash 

Cetirizine vs Loratadine Dosage Amounts

Cetirizine

NHS guidelines state the usual dosage for adults is 10 mg once daily, with a maximum of 10mg per day, and a lower dose for children based on age.  

It's important to remember to stick to the correct dosage because exceeding this can lead to increased sedation, headaches, dry mouth, and even more severe effects like heart issues or confusion.  

If cetirizine does not relieve your symptoms after a couple of days, or if you experience severe side effects, speak to your doctor. They may suggest adjusting your dosage, trying a different antihistamine, or exploring other treatment options if necessary. 

Loratadine

Loratadine 10mg is taken once a day as recommended on the NICE guidelines. This dosage is for most adults and children over 6 years old.  

If you take more than the recommended dosage, side effects including heart palpitations, dry mouth and drowsiness can occur. You should avoid drinking alcohol too because this can increase the sedative effects.  

Side effects shouldn’t last for more than a few days, however it's best to speak to your doctor for advice if they do.

Do Cetirizine and Loratadine Have Similar Side Effects?

Cetirizine 

One in ten people experience some drowsiness and sleepiness after taking Cetirizine. It's a very common side effect that usually subsides once the medication is out of your system.  

There are additional side effects to be aware of too, such as: 

  • Dry mouth 
  • Nausea 
  • Headaches 
  • Dizziness 
  • Diarrhoea 

Serious side effects are rare when taking cetirizine. 

Loratadine

Like cetirizine, feeling sleepy is the most common side effect of Loratadine. You may also experience: 

  • Headaches 
  • Sleep problems 
  • Drowsiness 
  • An increase in appetite 

These side effects are usually mild. It's worth making a note of any that you experience so that if they do not stop after a few days, you can inform your doctor or pharmacist. You can also report side effects using the MHRA yellow card system. 

Cetirizine vs Loratadine: Long-Term Use and Potential Interactions

Cetirizine

When taken at the recommended dosage, Cetirizine is considered safe to use long-term, particularly for chronic conditions like allergic rhinitis or chronic urticaria (hives). 

Long-term use requires more consistent monitoring to ensure that you’re still using the correct treatment for your symptoms.  

Some medications do cause interactions, which can affect your protection from hay fever symptoms and increase side effects. You should speak to your doctor if you take any of the following: 

  • Theophylline - for asthma or lung disease 
  • Cimetidine - for heartburn and ulcers 
  • Alcohol and CNS depressants - sedatives, tranquilizers, and some pain medications 

Loratadine

Loratadine tends to be well tolerated by most people when used for extended periods, but there is a possibility of rare side effects.  

It is not known to cause withdrawal or dependence symptoms. 

Some people, for example those with liver or kidney disease, may need to adjust their dosage and be monitored. Mild bouts of dry mouth and eyes, as well digestive discomfort can occur with long-term usage.

Price and Availability of Cetirizine and Loratadine

Cetirizine and Loratadine are the most affordable options when it comes to buying antihistamine tablets from Chemist Click. It is the same price for a one-month course of either treatment and will be delivered directly to your door. Cetirizine and Loratadine are readily available and easy to buy online or from your local high street pharmacy.  

Essential Safety Advice to Know Before Using Cetirizine or Loratadine

There is specific safety information that you should be aware of, whether you are taking antihistamines for the first time, or using them on a long-term basis to avoid and minimise your risk of adverse effects.  

There are also times when you need to share information about your health with your doctor. 

  • Pregnancy – both treatments are generally considered safe, but your doctor should be informed if you plan on taking cetirizine or loratadine  
  • Kidney or liver issues – these organs play an important role in filtering out this medication. You may need a lower dose if they are not functioning as they should.  
  • Alcohol – its best to avoid alcohol because you could feel increased sedative effects. 

You should always follow the medical advice and refer to the patient information leaflet. If you have any doubts, it's best not to take it and seek advice first.  

Cetirizine vs Loratadine: Which One is Best for You?

The best treatment is highly dependent on your specific needs including your symptoms, severity and lifestyle. It may be helpful to refer to the most common queries when it comes to choosing the best hay fever medication:  

  • Which antihistamine works the fastest? Cetirizine acts fast, delivering protection in as little as 20 minutes.  
  • Which antihistamines cause the least drowsiness? Both cetirizine and loratadine are non-drowsy, which means they are least likely to leave you feel sleepy. 
  • What antihistamine can I take every day? Most people can take antihistamines such as Cetirizine and Loratadine every day. The dosage is one a day, which protects against allergy symptoms for 24 hours.  
  • What is the most effective antihistamine for hay fever? Loratadine is good for daily use to treat hives and itchy skin, while Cetirizine is effective in targeting a runny or blocked nose, sneezing and sore, watery eyes.  

Manage Allergies and Hayfever with Confidence Using Award-Winning Online Phramacy Service from Chemist Click

It takes a few easy steps with Chemist Click to be on your way to alleviating bothersome hay fever symptoms thanks to our wide selection of antihistamine treatments and steroid sprays.  

Whether you’re looking for strong hay fever tablets such as Cetirizine (Zyrtec) and Fexofenadine Tablets or non-drowsy antihistamines such as Loratadine (Claritin), our team of in-house pharmacists are on hand to advise you on the best treatment for your symptoms.

FAQs

Can you Take Cetirizine and Loratadine in the Same Day?

No, this is not recommended because it can increase your risk of side effects such as drowsiness and fatigue. If you find one is not improving your hay fever symptoms, contact your doctor so they can assess your dosage and advise on the best treatment for your needs.  

Is Cetirizine the Strongest Antihistamine?

It is one of the stronger antihistamines for the treatment of hay fever and allergies, but there are stronger alternatives such as diphenhydramine (Benadryl). This is a first generation antihistamine which causes stronger sedative effects.

What is the Strongest Antihistamine?

Some of the strongest second-generation antihistamines for consistent, non-sedating relief are Cetirizine or Levocetirizine. Antihistamines such as Fexofenadine and Desloratadine are also strong but typically less effective than cetirizine for severe reactions. 

What is the Most Common Side Effect of Loratadine?

Drowsiness is the most common side effect of Loratadine affecting 1 in 100 people. 

Which is Better, Loratadine or Cetirizine?

This depends on your individual needs. Cetirizine may be better for you if you want an antihistamine that works fast, Loratadine may be better for you if you want to treat itchy skin and hives. 

Which is Better for Sleep, Cetirizine or Loratadine?

Cetirizine is more likely to cause drowsiness, but it is possible to experience this with either antihistamine.

Sources


Whilst all of our content is written and reviewed by healthcare professionals, it is not intended to be substituted for or used as medical advice. If you have any questions or concerns about your health, please speak to your doctor.

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