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Allergy tablets

Written by Healthwords's team of doctors and pharmacists based in UK | Updated: 21.02.2023 | 2 min read

Allergy tablets (also known as antihistamine tablets) are a group of medications that prevent the level of histamine from rising in our body and reduce the symptoms this can cause. Antihistamines can be used to treat a range of conditions, including allergic reactions, motion sickness, and insomnia.

Who should take allergy tablets?

If you are suffering from hay fever or allergic-type symptoms such as an itchy nose, itchy rash or bite on the skin, or redness and minor skin swelling, then an antihistamine may help relieve these symptoms for you.

Minor allergic reactions to products (washing detergent, creams, perfume) and food or plant reactions (stinging nettles) can be safely treated with over-the-counter antihistamines and should improve in hours to days. Make sure to avoid whatever caused the reaction in the future.

If you find that you are getting regular allergic reactions and do not know the reason why, you should discuss this with your doctor, and you may benefit from getting allergy testing.

Choosing an allergy tablet

Once-daily tablets are available to buy and contain loratadine, fexofenadine, levocetirizine, or cetirizine. They are similar in effectiveness, but you may find one works better than the other. They get to work within 1 to 3 hours, and they peak in effectiveness after 8 to 12 hours but last for at least 24 hours. At the recommended dose, they are unlikely to make you drowsy.

Drowsy allergy tablets

Older allergy tablets are more likely to cause drowsiness – this may be an advantage if symptoms are worse at night, but not if you need to operate heavy machinery or drive long distances. Those containing chlorpheniramine or diphenhydramine are older types. They work for a shorter amount of time, typically 4 to 6 hours, so you might need to take them several times a day or just when the pollen count is higher, typically early mornings and evenings. Despite this, some people think they work better for their particular symptoms – it's a question of trial and error on what works for you.

Prescription allergy tablets

All options discussed above are available to buy over-the-counter. You should speak with your doctor about other alternatives if they are ineffective.

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