Due to the increase in the incidence of
seasonal allergic reactions , the demand for
antiallergic drugs has also increased
. Until recently, second-generation
antihistamines were widely used. Compared with the previous group of medicines, these funds have some additional properties. In particular, they are effective in hay fever, bronchial asthma, dermatitis (atopic). However, they act only on peripheral histamine H1 receptors. Many of them have a cardiotoxic effect.
Recently, antihistamines of the third generation are more often used. The medicines used before them only reduced symptoms, without affecting in any way the sensitizing activity of allergens. In other words, with severe allergic reactions, their clinical effectiveness is low.
Modern medicines ( last generation antihistamines ) are distinguished by selectivity, do not pass through the blood-brain barrier. In this regard, these drugs do not have side effects associated with the activity of the central nervous system, and also do not adversely affect the function of the heart. Among the additional properties of drugs of significant clinical importance, the ability of medicines to reduce the phenomena of hyperreactivity of the bronchial system, the severity of bronchospasm (allergen-induced) should be highlighted.
The last generation
antihistamines are more appropriate for prolonged treatment of various manifestations of seasonal allergies, in the nature of which mediators of the late stages of inflammation are of no small importance. These include, in particular, prolonged rhinitis that can manifest itself throughout the year, seasonal rhinitis, conjunctivitis, which lasts more than two weeks,
chronic urticaria, dermatitis (atopic, contact allergic), as well as early atopic manifestations characteristic of children.
In the treatment of rhinitis, the most popular antihistamines of the latest generation are Acelastin, Loratadin, and Cetirizine.
The drugs "Cetirizine", "Zirtek" are also used for mild bronchial asthma. With the development of early atopic syndrome in young patients, these medications are considered basic. These latest generation antihistamines reduce the likely progression of atopic manifestations subsequently.
Medications "Claritin", "Loratadin" do not have a sedative effect. They do not differ in drug interactions that have significant clinical value. These antihistamines are allowed to be prescribed to patients of different ages.
Medications differ in pharmacokinetic properties. The most modern drugs have a long duration of action (up to two days). As a rule, they are taken once a day. It should be borne in mind that some third-generation antihistamines (for example, Astemizole and Terfenadine) have a pronounced cardiotoxic effect, causing disruptions in the heart rhythm.