Antihistamines are those drugs that block the H1 histamine receptors and not the other histamine receptors like H2, H3 and H4. These drugs act by block the histamine-induced responses in allergic reactions.
It is the most widely used allergy medicine for most of the common allergic diseases.
They're usually divided into two main groups: They also come in several different forms – including tablets, capsules, liquids, syrups, creams, lotions, gels, eye drops and nasal sprays.
There's not much evidence to suggest any particular antihistamine is better than any other at relieving allergy symptoms.
Many people find the worst symptom of their eczema is severe itching.
Often you will find that the itchiness of your skin is reduced when you use regular moisturisers to keep the skin soothed and hydrated, and control the inflammation with topical corticosteroids or other newer medicines.Although the sedative effect of antihistamines are sometimes desired, like in a patient with allergic rhinitis who is having difficulty sleeping, generally the use of these drugs should be limited in a person who is driving or operating heavy machinery.Some of the first generation antihistamines also block other receptors like cholinergic (muscarinic) receptors and alpha adrenergic receptors.Most antihistamines can be bought from pharmacies and shops, but some are only available on prescription.This page covers: Types of antihistamines How to take them Side effects Taking them with other medicines, food or alcohol Who can take them – including pregnancy advice How they work There are many types of antihistamine.Antihistamines are medicines often used to relieve symptoms of allergies, such as hay fever, hives, conjunctivitis and reactions to insect bites or stings.