How do Antihistamines Work?

Published on May 23, 2022

Woman sneezes into tissue next to flowers

What are antihistamines?

Antihistamines are used by allergy sufferers to relieve allergy symptoms from seasonal and year-round allergies.

What types of antihistamines are there?

Two types of antihistamines are used for allergies. They are known as first-generation and second-generation antihistamines.

First-generation antihistamines

First-generation antihistamines commonly have drowsiness as a side effect that can affect your ability to operate machinery, drive your car and think clearly. Some adults may use these medicines over a short-term for the drowsiness effect under the advice of a doctor or pharmacist particularly where allergic symptoms such as runny or congested nose affect sleep.

Second-generation antihistamines

Second-generation antihistamines are less likely to cause drowsiness and are used primarily for their anti-allergy effects.

Can antihistamines cure my allergies?

Antihistamines can’t cure allergic conditions, but they can provide much-needed symptomatic relief from the symptoms of:

  1. Hayfever (allergic rhinitis) — This common allergic condition can cause sneezing, runny nose, inflammation of nose and eyes, and itching of eyes, nose and throat.
  2. Allergic skin conditions — Such as mild allergic eczema, rashes, hives (urticaria) and generalised itching.
  3. Allergic conjunctivitis — Inflammation of the eyes, red, itchy and watery eyes.
  4. Insect bites and stings — If there is an allergic reaction, symptoms of raised circular welts that may be itchy can appear.

How do antihistamines work?

As the name suggests, antihistamines work by stopping the effects of histamine. Histamine is a chemical substance released by the body’s immune system as a response to an allergen. In an allergic reaction, too much histamine is released, leading to symptoms such as a runny nose, itchy eyes and swelling.

How do I choose an antihistamine?

Your doctor or pharmacist may advise a particular antihistamine, depending on the type and cause of your allergy.

Where can I buy antihistamines?

Second-genaration antihistamines are available over the counter at your pharmacy without a prescription. Talk to your pharmacist to work out which antihistamine would be best for you.

What is Telfast?

Telfast is a second-generation antihistamine, which means it is less likely to cause drowsiness than first-generation antihistamines.

Telfast can help to manage the symptoms of hayfever allergies, year-round allergic rhinitis, and itchy skin rash or hives.

Telfast tablets are available in three different strengths, each with its own indications:

  • Telfast 60mg strength: Seasonal hayfever and year-round allergic rhinitis
  • Telfast 120mg strength: Seasonal hayfever allergies
  • Telfast 180mg strength: Seasonal hayfever allergies and itchy skin rash/hives

Always read the label and follow the directions for use.

How does Telfast 180mg work?

Telfast 180mg is the highest strength of Telfast available — it contains 180mg of the active ingredient fexofenadine hydrochloride (HCl).

Fexofenadine HCl acts quickly (within 1 hour) without causing drowsiness to help relieve the symptoms of hayfever allergies by blocking histamine receptors in the body.

Telfast 180mg can be taken daily for relief from seasonal hayfever allergy symptoms. As allergy symptoms often peak in the morning, fast-acting (within 1 hour) treatments such as Telfast 180mg can help provide relief from seasonal hayfever allergy when you need it most.

Why should I use Telfast 180mg for my allergy symptoms?

  1. Fast acting – Telfast 180mg works within an hour of taking it for fast much-needed relief from allergy symptoms.
  2. Non-drowsy – The active ingredient fexofenadine HCl is a second-generation antihistamine that does not cause drowsiness.
  3. 24 hour symptom relief – Telfast 180mg provides a convenient one-a-day tablet for 24-hour relief.
  4. Multi-symptom relief – Telfast 180mg provides relief from the multiple symptoms of seasonal allergic rhinitis and hives, including sneezing, runny nose, nasal congestion, itching and skin rashes.
  5. May be used every day – Telfast 180mg may be used every day to help provide relief from seasonal hayfever allergy.

Who should take Telfast 180mg?

Telfast 180mg is suitable for most hayfever allergy symptoms. Its 5-in-1 multi-benefit relief helps ease symptoms such as sneezing, itchy and runny nose and itchy throat. It is also suitable for those suffering from itchy skin rash or hives (urticaria) associated with allergies.

For hayfever allergy sufferers who want fast, non-drowsy and long-lasting relief, consider Telfast 180mg.

Who should not take Telfast 180mg?

Caution is required if you are pregnant or may become pregnant. If you are breastfeeding, check with your doctor or pharmacist before taking this medicine. Not recommended for children under the age of 12 years. For children under the age of 12 years, Telfast Oral Liquid can be used for the relief of itchy skin rash or hives from 6 months and hayfever allergies from 2 years.

Always read the label and follow the directions for use.

Learn about which Telfast product may be appropriate for you.


MAT-AU-2102100. Nov 2021.

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