Sedating side effects
They have a number of uses, but are most often used to treat allergies.If you are one of the many people who get hay fever each year, you will know all about antihistamines.If these receptors are affected, you may experience some of the side-effects associated with antihistamines.For example, dry mouth, blurred vision and retention of urine.
This means that the medicine can also block another type of receptor found on the surface of certain cells.For example: For other conditions, specific antihistamines may be used.For example, cyclizine and promethazine teoclate are used for feeling sick (nausea) and being sick (vomiting), not for hay fever.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.An allergen is a substance that is foreign to the body and which can cause an allergic reaction in certain people. In most people, the immune reaction to these foreign substances is normal and appropriate. For example, in people with hay fever, contact with pollen in the nose, throat and eyes triggers the mast cells there to release much more histamine than normal.This excessive release of histamine produces the associated symptoms of itching, swelling, runny eyes, etc.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.This sets off a chain reaction which causes blood vessels in the area to become slightly leaky.Specialised cells and chemicals, which defend your body, can now get access to the area.