Antihistamines work by physically blocking the H1 receptors, stopping histamine from reaching its target.This decreases your body's reaction to allergens and therefore helps to reduce the troublesome symptoms associated with allergy.Antihistamines are a group of medicines which act by blocking the action of the chemical called histamine in the body.
These effects are mainly caused by the older first-generation antihistamines which are described below.
Note: antihistamines should not be confused with H2 blockers which reduce the production of stomach acid.
While this is a helpful response, it also causes redness, swelling and itching.
Allergic reactions such as hay fever (seasonal allergic rhinitis) are caused by an oversensitivity or over-reaction of the immune system to a particular allergen.
The brain has several key areas which control vomiting.
It is thought that antihistamines block H1 receptors in the area of the brain which creates nausea in response to chemicals in the body.Your doctor or pharmacist will advise you on how to take your medication, including what dose and how often.Read the leaflet that comes with your particular brand for further information.Antihistamines are also used in the treatment of feeling sick (nausea) and being sick (vomiting).However, the exact way that they ease these symptoms is not fully understood.Generally, antihistamines have been classified into two groups: All antihistamines work pretty well to reduce symptoms of allergy.