What kinds of antihistamines should be used to treat allergies?
There are 2 types of antihistamines available in Australia:
- First-generation (sedating) antihistamines often cause sleepiness. Examples of sedating antihistamines include Phenergan® and Polaramine®.
- Second-generation (less sedating or non-sedating) antihistamines that usually do not cause sleepiness. Examples include Claratyne®, Desonex®, Telfast® and Zyrtec®.
Antihistamines available in Australia
| Examples of less or non-sedating antihistamines Active ingredient and example brand | Examples of sedating antihistamines Active ingredient and example brand |
| Cetirizine (eg: Zyrtec®) | Dexchlorpheniramine (eg: Polaramine®) |
| Desloratadine (eg: Desonex®) | Promethazine (eg: Phenergan®) |
| Fexofenadine (eg: Telfast®) | |
| Loratadine (eg: Claratyne®) |
Antihistamines for allergic reactions
It is recommended that sedating antihistamines should not be used to treat allergic reactions. Sedating antihistamines can make people drowsy (sleepy) which makes it hard to know whether the person is drowsy because of the antihistamine or because of a drop in blood pressure due to a severe allergic reaction (anaphylaxis).
Less sedating or non-sedating antihistamines are recommended to manage signs and symptoms of mild to moderate allergic reactions, such as hives, welts or swelling of the face, lips, eyes, tingling of the mouth.
Antihistamines (sedating or non-sedating) DO NOT prevent or treat severe allergic reactions (anaphylaxis), which involves the following signs and symptoms: difficult or noisy breathing, swelling of tongue, swelling or tightness in throat, wheeze or persistent cough, difficulty talking or hoarse voice, persistent dizziness or collapse and pale and floppy (young children).
Anaphylaxis must be treated promptly with adrenaline (epinephrine) using an adrenaline device, such as an EpiPen® or Anapen®, following instructions on the ASCIA Action Plan for Anaphylaxis.
Age recommendations for type of antihistamine
First-generation sedating antihistamines – Since 1 September 2020, all over-the-counter first-generation sedating antihistamines have been required to carry the warning ‘Do not give to children under 2 years of age’. The Therapeutic Goods Administration (TGA) has updated its advice for promethazine hydrochloride, sold as Phenergan® and other generic brands in November 2024
A MEDICATION SAFETY ALERT states that promethazine hydrochloride (Phenergan®) should not be used in children under six years of age as it has been found to cause a range of side effects such as hyperactivity, aggression and hallucination.
Second generation less or non-sedating antihistamines – Some of the less or non-sedating antihistamines are registered for use in infants 6 months and older, whilst others can be used from 12 months of age.
Always read the label and talk with your pharmacist or doctor about the right antihistamine for you or your child.
Antihistamines are available in different forms: tablet, liquid or chewable tablet.
Tablet
- Designed to be swallowed
- Easy to carry and pack in medicine kits
For people who are unable to swallow a tablet due to their age, medical condition or a disability, antihistamines that come as a liquid or chewable tablet form could be considered. Both liquid and chewable antihistamines work effectively.
Chewable tablets
- Made to be chewed and don’t require water to swallow them
- Easy to carry and pack in medicine kits
- Available for children over 2 years of age
- Worth checking that your family member is able to chew the tablet before relying on it during an allergic reaction.
Liquid antihistamine
- Liquid is easy to swallow
- Taste varies depending on brand and flavour
- More difficult to carry as the bottle is bulky and there is a risk of leakage
You may wish to have the liquid at home and the chewable tablets when out and about if your child is old enough for the chewable tablets.
Ask your pharmacist or doctor about the best choice of antihistamine for you or your family member.
Antihistamines in schools and childcare – what should be written on the ASCIA Action Plan?
It is important that the antihistamine medicine that you give to childcare or school matches the antihistamine written on your child’s ASCIA Action Plan for Allergic Reactions or ASCIA Action Plan for Anaphylaxis.
Check that the following information matches:
- The name of the antihistamine.
- The dose (how much) of antihistamine that is to be given.
Remember that medications have two names – the generic name (also called the active ingredient) and the brand (trade) name. Both names are written on the packaging.
Some examples that may be used are shown in the table below:
| Generic name | Brand name examples |
| Cetirizine | Zyrtec, C-Zine |
| Loratadine | Claratyne, Lorastyne |
| Fexofenadine | Telfast, Fexo |
If the doctor or nurse practitioner only writes the brand name on the ASCIA Action Plan and the parent buys a different brand, childcare or school staff may not know that this is the same medication and may not give it.
It is best if the generic name is written on the ASCIA Action Plan by your doctor or nurse practitioner. This allows families to have choice of which brand of the generic antihistamine they want to buy. Please speak with your pharmacist if you are unsure about generic and brand names.
The form of antihistamine (tablet, chewable tablet, syrup or drops) is not required to be written on the ASCIA Action Plan. However, if the doctor or nurse practitioner has written the form of antihistamine, the medication you provide the school or childcare service should match.
Remember that if the medication doesn’t match the ASCIA Action Plan, staff may not give the antihistamine but should still follow the other instructions.
Antihistamines are used to treat mild to moderate allergic reactions only. The treatment for anaphylaxis is always to give an adrenaline device (such as EpiPen® or Anapen®) following the instructions on the ASCIA Action Plan.
For more information visit our Schools page or Childcare page.
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