mechanism of action of antihistamines
allergic reactions, which has various manifestations, is the allergen under the influence of which the body begins to produce biologically active substances, the excess of which leads to allergic inflammation.These substances are many, but the most active is histamine, which is normally found in mast cells and is biologically neutral.After becoming active under the influence of an allergen, histamine causes the appearance of irritation and nuisance symptoms like skin rashes and itching, swelling and runny nose, conjunctivitis and redness of the sclera, bronchos
What are antihistamines
These drugs are divided into two groups.The first is commonly used for the relief of symptoms of allergic diphenhydramine, promethazine, suprastin, tavegil, diazolin and Phencarolum, also called old generation drugs.They all tend to have one common side effect - cause drowsiness.To a new generation of drugs include, for example, astemizole (gismanal) and Claritin (loratadine).The main difference between these two groups of antihistamines that the new generation of drugs have no sedative effect and should be taken once a day.However, the cost of these drugs is much higher than the "classical".
Other pharmacological properties of antihistamines
addition suppression and neutralization of histamine, these drugs have other pharmacological properties, which should be taken into account, if you buy them without a prescription.Thus, most of them have the ability to enhance the effect of other drugs so often as reinforcement analgesic effect is used, for example, such a combination as diphenhydramine and Analgin.These drugs also increase the effectiveness of drugs that have effects on the central nervous system, therefore co-administration may cause an overdose and have unpredictable consequences.
with acute respiratory diseases should not take allergy medications such as diphenhydramine, promethazine, or suprastin tavegil.They dried mucous membranes and make it more dense and viscous sputum produced as a light, giving her cough, which may increase the risk of pneumonia.There are other side effects of antihistamines, which are known only to specialists, so before taking this or that remedy, consult your doctor.
Tip 2: How to choose an antihistamine
correct choice of antihistamine allows permanently get rid of the unpleasant symptoms of allergies, prevent the occurrence of allergic reactions and to cope with a variety of allergy-related illnesses.Despite the huge variety of this type of products on the shelves of modern pharmacies and choose the most suitable and really good antihistamine is not so difficult.
The efficiency of first generation antihistamines in the presence of already developed distinct manifestations of allergies low.However, even this fact did not affect the popularity of their use.Antihistamines are the first generation are optional components of the set of complex drugs aimed at the treatment of colds and to strengthen the effectiveness of local anesthetic drugs. significant disadvantage of the first-generation antihistamines is that they have side effects such as drowsiness.
As an independent drug they used most often to eliminate the discomfort and pain of burns, insect bites, minor cuts and injuries.They are actively used to alleviate the condition of people exposed to motion sickness and seasickness.Using the first-generation antihistamines to prevent the emergence of occasional seasonal allergies, eliminate the development of the food and drug allergies, and eliminate the symptoms of urticaria, angioneurotic edema and anaphylactic shock.
most popular and effective first-generation antihistamines are considered "Suprastin", "Tavegil", "Diazolin" "Fenistil" and "Diphenhydramine".
Antihistamines second generation
second-generation antihistamines, such as "Ketotifen" and its analogs, are appointed doctors rarely and are most commonly used for the treatment of diseases such as asthma and atopic dermatitis.Most doctors try to replace the drugs in this group of the third generation antihistamines.
Antihistamines third generation
According to the experts and reviews of patients, antihistamines third generation deprived of many deficiencies existing first- and second-generation, so use them can be for the prevention of allergic reactions, as well as for long-term treatment of allergies. most important advantage of the third-generation antihistamines is considered to be their lack of side effects in the nervous system.
The most common third-generation antihistamines are used to treat asthma, and chronic contact dermatitis, hives, hay fever, and autoimmune diseases.Also, experts recommend the use of third-generation antihistamines people an important role in professional activities which play focus, clear thinking and quick reflexes.
most popular antihistamines in this group are: "Claritin", "Kestin," "Zyrtec", "Allergodil" "Telfast" and "Levobastin."