Allergic reaction, namely allergic reaction, refers to the tissue damage or physiological function disorder caused by the stimulation of antigenic substances. It is an immunopathological damage process. The drugs for preventing and treating allergic diseases caused by various antigenic substances (such as bacteria, viruses, parasites, pollen, etc.) are anti allergic drugs, also known as anti allergic drugs. According to different action mechanisms, they can be divided into the following categories:
Antihistamines. Histamine H1 receptor antagonists, such as diphenhydramine, promethazine and Chlorphenamine, are commonly used in clinic. They are the most widely used nonspecific abnormal antiallergic drugs. They can compete with histamine for histamine H1 receptor on effector cells, so that histamine can not bind to H1 receptor, so as to inhibit its allergic reaction.
Allergic reaction medium release inhibitor. It can stabilize mast cell membrane, prevent the release of histamine and other allergic reaction media, and produce anti allergic effects, such as sodium cromoglycate, ketotifen, etc.
Histamine desensitizer. For example, histamine H1 receptor agonist betahistine, low-dose histamine diluent, dust mite injection, etc. shall be injected repeatedly to improve the tolerance to histamine.
Leukotriene receptor antagonist. Such as monroest and zarust, which are mainly used for respiratory allergies.
Drugs that inhibit antigen antibody response, such as adrenal glucocorticoid, immunosuppressant, etc.
Drugs to improve or control allergic symptoms, including smooth muscle antispasmodics, such as salbutamol; Including drugs to reduce edema caused by allergy, such as calcium gluconate.
Since histamine H1 receptor antagonists account for the vast majority in clinical use, histamine H1 receptor antagonists are mainly introduced below.
Scope of application
Histamine H1 receptor antagonists are mainly used in skin and mucosal allergic diseases, such as urticaria, allergic rhinitis and skin pruritus and edema caused by insect bites; It has antipruritic effect on pruritus caused by serum disease, drug rash and contact dermatitis; The curative effect on allergic bronchial asthma is poor; It has no effect on anaphylactic shock.
The main adverse reactions of histamine H1 receptor antagonists are headache and drowsiness caused by pivot inhibition, dry mouth, blurred vision, dysuria and constipation caused by anticholinergic effect.
matters needing attention
Newborns and preterm infants are sensitive to the anticholinergic effect of histamine H1 receptor antagonists and should not be used; Antihistamines can inhibit the skin test reaction of allergenic substances. Therefore, all antihistamines should be stopped several days before the skin test to avoid affecting the skin test results. Antiallergic drugs have side effects.
It is not suitable to take a certain antiallergic drug in large doses for a long time. Otherwise, it is not only easy to cause drug failure, but also various adverse reactions and even toxic and side effects in serious cases. If you need to take other Western medicine while taking anti allergy drugs, you must consult a doctor.
(Note: the above contents are only for introduction. The use of drugs must be carried out under the guidance of doctors in regular hospitals.)