Antihistamines from allergies
The most common and effective are considered antihistamines, which over the past decades have gone through several stages of improvement. It is these medicines that are designed to block histamine, a mediator of inflammatory allergic processes. Drugs from this type of allergy cope effectively with H2-histamine receptors, moreover antihistamines are successfully used in gastroenterology as antiulcer therapy. Antipruritic action, neutralization of spasms, counter-current and local anesthetic properties make it possible to widely use these means in the fight against the enemy of the 21st century - an allergy.
Antihistamines are divided into generations - I, II, III. The first generation of antihistamines has a pronounced sedative effect, these drugs are called sedative antihistamines. The second generation is more perfect and is called non-sedentive antihistamine drugs. Completely new in the mechanism of penetration, pharmacokinetics and bioavailability are third-generation drugs, called active metabolites.
, , , 
Allergy medications are the first generation, sedative antihistamines
These drugs are able to combine with H1-receptors, they act as cholinolytics (breaking the connection of neurotransmitters, preventing the transfer of momentum to the nervous system), have a sedative effect. The antihistamine effect lasts up to 8 hours, then the drug must be taken again. The sedative effect is explained by the fat-solubility of first-generation antihistamines and the excellent ability to overcome the blood-brain barrier of the brain. In connection with the sedative effect, antihistamines of this generation are limited in prescriptions, as well as have limitations in the combination of combination therapy. Such drugs are not prescribed together with some types of analgesics, anti-inflammatory drugs. Antihistamines of the first generation can give atropine-like manifestations - urinary retention, dry mouth, tachycardia, stool disorder, visual impairment. Among the positive properties of anti-histamine preparations of the 1st generation, one can name antiemetic effect and tremor reducing property, which makes it possible to prescribe similar therapy for parkinsonisms. Also these antihistamines can have a local anesthetic effect. The disadvantage is that over time (2-3 weeks) the body becomes tolerant to the drug and must be changed. The therapeutic effect comes quickly enough, but it is not prolonged and unstable. In the group of drugs of this generation, dimedrol can lead in popularity and popularity. The second position in the ranking is diazolin, followed by suprastin and tavegil. Pipolphen and fenkarol are less known in the people, but doctors are well acquainted with clinicians, especially those who have worked in the medical field for more than thirty years.
, , , , , , 
Drugs from allergies: the second generation of antihistamines
These medicines are not accidentally called non-sedating antihistamines. Penetration through the blood-brain barrier in them is minimal, hence the sedative effect is very insignificant. However, the main function - the blocking of H1-receptors, second-generation antihistamines perform perfectly. Among the minuses of these drugs should be noted their cardiotoxicity. Subject to their appointment, continuous monitoring of the patient's cardiac activity and additional maintenance therapy are necessary. Cardiotoxicity is associated with blocking not only the H1 receptor, but also the potassium channels of the heart muscle. Toxicity can increase in complex therapy with antifungal agents and antidepressants. It is also necessary to exclude drugs and foods containing vitamin C and citrus fruits.
It is not recommended to prescribe antihistamines of this generation to elderly people, pregnant women. The therapeutic effect can be seen immediately, lasts more than 10 hours, often up to 14 hours, which makes it possible to use drugs less often, and therefore to minimize side effects. Possible long-term use without addiction and withdrawal syndrome. Among the second generation antihistamines, one can name treksil, astemizol, semprex, the more popular fenistil, even more famous claritin or loratadine.
, , , , , 
Preparations for allergies: antihistamines of the third generation
These are active metabolites that do not have a sedative effect and are absolutely safe for cardiac activity. They can be prescribed even if the patient's activity is related to active functions and the need for concentration. They also cope well with the blocking of H1 receptors, I work day, the reception is not dependent on the time of eating, that is, drugs can be taken when convenient, but daily. The list of antihistamines of the third generation includes telphast, erius, levocetirizine hydrochloride, better known as xylol. The form of release of these medicines can be tableted, but often active metabolites are produced in syrups, which is very attractive in case of antiallergic therapy of children.
Drugs for allergies are not limited only to antihistamines, the medical complex includes nasal sprays, drops for the eyes and even glucocorticoids. Also, at times a "veteran" is appointed among medicinal products - calcium chloride. In any case, the medicine should appoint an allergist, because the choice of the drug directly depends on the type of allergy, allergen and the general condition of a person.