Anti-leukotriene preparations are a new class of anti-inflammatory drugs that have an infectious or allergic etiology.
In order to understand the principle of action of such drugs, it is worth understanding what leukotrienes are.
Leukotrienes
They are mediators of inflammatory processes. By their chemical structure, they are fatty acids, which are formed by arachidonic acid.
Лейкотриены принимают участие в процессе развития bronchial asthma. Like histamine, they mediate immediate-type allergic reactions. Histamine can cause a rapid but short-term spasm of the bronchi, and leukotrienes cause a delayed and more prolonged spasm.
How are anti-leukotriene preparations classified?
The following leukotrienes are currently classified: A4, B4, C4, D4, E4.
Synthesis of leukotrienes comes from arachidonic acid. Under the influence of 5-lipoxygenase, it becomes Leukotriene A4. After this, a cascade reaction occurs, resulting in the following leukotrienes B4-WITH4-E4-E4. The end product of this reaction is LTE.4.
It is established that LTE4, D4, E4 can cause a bronchoconstrictor effect, increase the secretion of mucus, can contribute to the development of puffiness, inhibit mucociliary clearance.
AT4, D4, E4 have chemotactic activity, that is, they can attract neutrophils and eosinophils to the area of the inflammatory process.
Scientists have proven that leukotrienes are producedmacrophages, mast cells, eosinophils, neutrophils, T-lymphocytes, which are directly involved in the inflammatory response. Anti-leukotriene drugs for bronchial asthma are often used.
After the cells came into contact withan allergen and there was a cooling of the respiratory tract or after exercise, the synthesis of RT is activated. That is, the synthesis begins when the osmolarity of the bronchial content increases.
Four groups of drugs
Currently, only four groups of anti-leukotriene preparations are known:
- "Zileuton", which is a direct inhibitor of 5-lipoxygenase.
- FLP inhibitors that prevent the binding of this protein to arachidonic acid.
- Zafirlukast, Pobilukast, Montelukast, Pranlukast, Verlukast, which are antagonists of sulfide-peptide leukotrienes.
- Drugs that are antagonists of leukotriene B receptors4.
The most studied are anti-leukotriene preparations of the first group and the means of the third group. Consider the representatives of these groups a little more.
Zileuton
"Zileuton" is a reversible inhibitor of 5-lipoxygenase. It is able to inhibit the formation of sulfide-peptide LT and LT4. The drug may have bronchodilatorexposure duration of up to five hours. It is also able to prevent the occurrence of bronchial spasm, which is a consequence of exposure to cold air or "Aspirin".
Многочисленные исследования доказывают, что "Zileuton", assigned to patients suffering from asthma for one to six months, can reduce the patient's need for inhalation of β2-adrenomimetics and glucocorticoids. A single dose of "Zileuton" prevents the occurrence of sneezing and difficulty in nasal breathing in those patients who suffer from allergic rhinitis after the introduction of the allergen nasal.
Six-week therapy with the use of "Zileuton"patients with atopic asthma showed a significant result. Doctors say a qualitative decrease in the level of eosinophils and neutrophils. The tumor necrosis factor in bronchoalveolar-type lavage fluid also decreased after the allergen test. This is what unique anti-leukotriene drugs are, the mechanism of action is based on this.
“Zileuton” is characterized by rather shorta period during which it is half-life. This suggests that the drug should be taken quite often, up to four times a day. In addition, Zileuton is able to lower the clearance of theophylline. This must be taken into account if a parallel reception of theophylline and Zileuton is intended. That is, the dose of the first should be reduced. If Zileuton is prescribed for a long time, then the level of hepatic enzymes should be monitored.
But there are new-generation anti-leukotriene preparations, their list is presented below.
Agents that are antagonists of sulfidopeptide leukotrienes are highly selective competitors and reversible LT D receptor blockers.4. Such drugs include Pranlukast, Zafirlukast, Montelukast.
Akolat (Zafirlukast)
«Зафирлукаст», он же «Аколат», является наиболее studied drug of this group of anti-leukotriene substances. It also has a bronchodilator activity. The effect lasts quite a long time, up to five hours. "Zafirlukast" is able to prevent the development of an asthmatic reaction in case of inhalation with an allergen. Its effectiveness has been proven in the prevention of bronchospasm, which is provoked by cold air, aspirin, exercise, and pollutants. This drug, as well as Montelukast, is capable of enhancing the bronchodilator activity of β2-adrenomimetics.
"Akolat" ("Zafirlukast") has a goodabsorbability, the peak of its concentration in the blood is reached after three hours after taking it. Its half-life is a little longer than that of Zileuton, and is 10 hours. In addition, it does not affect the clearance of theophylline. Take this drug should be either an hour before a meal, or at the end of two hours after it, as the food significantly reduces its absorption capacity. The remedy is well tolerated by patients.
Conclusion
Anti-leukotriene drugs for allergiesuse for children, but not earlier than they reach two years of age. With the help of these medications for children, recurrent bronchitis, allergic rhinitis, mild bronchial asthma are treated.
