What is the difference between antihistamine and antiallergic. Antihistamines - generations, principles of action, overview of drugs
Allergic reactions are divided into immediate, developing immediately after exposure to the antigen, and delayed, manifesting itself after several days or even weeks. At immediate type allergies are most effective antihistamines. The principle of their action is based on blocking free histamine, which is released in the body in response to a physical or chemical stimulus. Possessing a structure similar to that of a biogenic amine, the active substance blocks histamine receptors, preventing the amine itself from acting as a mediator of allergic reactions.
There are three generations of antihistamines. Designed in different time, they differ in the selectivity of action. Each of the subsequent pharmaceutical lines is more selective, that is, the active substance of the drug binds mainly to one type of receptor. This increases the safety of drugs and reduces the risk of side effects.
The first generation was created in 1936, its representatives are Dimedrol, Diazolin, Tavegil, Suprastin, Fenkarol. They show good results as histamine blockers: they eliminate allergic manifestations in the form of a rash, swelling, itching. However, all these drugs have a short-term effect (3-4 hours), and with prolonged use they reduce their activity, and also give quite a lot of side effects:
- due to low selectivity, they have an undesirable effect on the cellular structures of many organs, and therefore are contraindicated in peptic ulcer, renal, hepatic and cardiovascular pathologies, glaucoma, epilepsy;
- being anticholinergics, they can cause dysfunctions of the central nervous system, headache, dizziness, falling blood pressure;
- reduce muscle tone;
- have a hypnotic effect;
- cause an increase in body weight.
Important information!
Due to the pronounced sedative effect antihistamines of the first generation, in case of their use, it is possible to drive, as well as perform other work that requires increased attention or a quick reaction, only 12 hours after taking the medicine.
Second-generation drugs - Hexal, Clarisens, Kestin, Claritin, Clarotadin, Lomilan, Zirtek, Rupafin and others - appeared in the 80s of the last century. They act more selectively, affecting mainly histamine receptors, and therefore have fewer side effects.
The advantage is also the lack of addiction and the duration of action up to 24 hours. This allows you to take the medicine once a day and not increase the dose with prolonged use. However, due to the cardiotoxic effect, when taking most of these drugs, constant monitoring of cardiac activity is required, and 2nd generation antihistamines are contraindicated in patients with serious cardiovascular pathologies.
In recent years, for the treatment of all types of allergies, drugs have been successfully used, the active substances of which belong to the category of prodrugs, that is, they turn into pharmacologically active compounds already in the body, as a result of metabolic processes. The effectiveness of these funds is several times higher than that of their predecessors. They are also highly selective, and therefore do not produce any sedative or cardiotoxic effect, and therefore are the safest.
The list of new generation antihistamines is still relatively small, but they all have a common advantage: they are allowed to be taken for diseases of the heart, gastrointestinal tract, kidney and liver pathologies, as well as for people whose work requires a high concentration of attention. Some of the drugs in this group are not contraindicated during pregnancy and childhood.
Comparative characteristics of 3rd generation drugs
Indications for the use of this category of drugs are:
- food allergy;
- seasonal and chronic allergic conjunctivitis and rhinitis;
- hives;
- exudative diathesis;
- contact and atopic dermatitis.
Preparations with the same active substance may be produced under different trademarks(these are the so-called drugs-synonyms).
Allegra
It is also produced under the names Feksadin, Fexofenadine, Telfast, Fexofast, Tigofast. The active substance is fexofenadine hydrochloride. Release form - tablets of 120 and 180 mg film coated.
The initial effect gives an hour after administration, the maximum concentration in the blood reaches after 3 hours, the half-life is about 12 hours, the duration of action is a day. A single dose is 180 mg, the course of treatment is determined individually. Because the clinical researches effect of fexofenadine on the fetus and children's body were not carried out, during pregnancy, children under 12 years of age and lactating women are prescribed it only in case of special need.
The cost of drugs depends on the content of the main substance and the manufacturer. For example, 10 tablets of 120 mg of Feksadin Ranbaxy (India) cost 220 rubles, the same package of Allegra from Sanofi-Aventis (France) costs 550 rubles, and 10 tablets of 180 mg of Telfast Sanofi-Aventis cost 530 rubles.
cetirizine
Other trade names: Tsetrin, Tsetrinal, Parlazin, Zodak, Amertil, Allertek, Zirtek. Cetirizine dihydrochloride serves as a substance showing activity in relation to histamine. Available in tablets containing active substance 10 mg, as well as in the form of drops, solutions and syrup.
The initial effect is observed 1-1.5 hours after ingestion, the total duration of action is up to a day, metabolites are excreted within 10-15 hours in the urine. Single (and daily) dose of 10 mg. The drug is not addictive and can be used for long-term therapy. Children under 1 year of age and pregnant women are not recommended to take it.
The approximate cost of cetirizine and its analogues:
- Cetirizine, manufacturer Vertex, Russia (10 tab.) - 66 rubles;
- Tsetrin, manufacturer Dr. Reddy, India (20 tablets) - 160 rubles;
- Zodak, manufacturer Zentiva, Czech Republic (10 tab.) - 140 rubles;
- Zirtek, manufacturer YUSB Farshim, Belgium (drops in bottles of 10 ml) - 320 rubles.
Xizal
Synonyms: Suprastinex, Levocetirizine, Glentset, Zilola, Alerzin. The active substance is Levocetirizine dihydrochloride. The medicine is available in 5 mg tablets and drops, the dosage form for children is syrup.
The affinity for histamine receptors in this drug is several times higher than in the rest of the representatives of this series, so its effect lasts for 2 days. Metabolic products are excreted by the kidneys, the half-life is 8-10 hours. The daily dose for adults and children over 6 years old is 5 mg. Contraindications to the use of levocetirizine are congenital disorders carbohydrate metabolism.
Estimated cost of drugs:
- Ksizal, manufacturer YUSB Farshim, Belgium (drops in bottles of 10 ml) - 440 rubles;
- Levocetirizine, manufacturer Teva, France (10 tab.) - 270 rubles;
- Alerzin, manufacturer Eric, Hungary (table 14) -300 rubles;
- Suprastinex, manufacturer Eric, Hungary (table 7) - 150 rubles.
Desloratadine
Other trade names: Erius, Desal, Allergostop, Fribris, Alersis, Lordestin. The bioactive substance is desloratadine. Release form: 5 mg film-coated tablets, solution containing active substance 5 mg/ml and syrup.
The maximum concentration in the blood is observed after 3-4 hours, the half-life is 20-30 hours, the total duration of action is 24 hours. A single dose for adults and children over 12 years old is 5 mg, the dosage for children from 2 to 12 years old is determined individually. For pregnant and lactating women, the drug is prescribed for conditions that pose a threat to life.
The cost of desloratadine and its synonyms:
- Desloratadine, manufacturer Vertex, Russia (10 tablets) - 145 rubles;
- Lordestin, Bayer, USA manufacturer Gedeon Richter, Hungary (10 tab.) - 340 rubles;
- Erius, manufacturer Bayer, USA (7 tablets) - 90 rubles.
All antiallergic drugs are prescribed by a doctor, taking into account the specifics of their action, the reasons for the development of allergies, the age and characteristics of the patient's body. When taking antihistamines, you should strictly adhere to the rules specified in the instructions.
New generation antihistamines - the most effective drugs in the treatment of allergies
Drugs that block histamine receptors in the body and thereby inhibit the effects it causes are called antihistamines.
What is histamine
Histamine is a mediator that is released from the connective tissue during allergic reactions and has a negative effect on the organs and systems of the body: skin, Airways, cardiovascular system, digestive tract and others.
Antihistamines are used to suppress free histamine and are divided into 3 groups depending on the receptors they block:
- H1-blockers - this group of drugs is used in the treatment of allergic diseases.
- H2-blockers - are indicated for diseases of the stomach, as they have a positive effect on its secretion.
- H3 blockers are used in the treatment of neurological diseases.
Currently, there are many antihistamines:
- Diphenhydramine
- Diazolin
- Suprastin
- Claritin
- Kestin
- Rupafin
- Lorahexal
- Zyrtec
- Telfast
- Erius
- Zodak
- Parlazin
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They are divided into three generations of drugs for the treatment of allergic diseases.
- The first generation of antihistamines, called classic, these include:
- diphenhydramine
- diazolin
- suprastin
- fenkarol
- tavegil
The mechanism of their action consists in a reversible connection with peripheral and central H1 receptors, which blocks various effects histamine: increased vascular permeability, contraction of the muscles of the bronchi and intestines. They quickly overcome the blood-brain barrier, while binding to the receptors of the brain, hence the powerful sedative and hypnotic effect.
Pros: these drugs act quickly and strongly - after half an hour, a decrease in allergic symptoms is achieved. They also have an anti-sickness and antiemetic effect, reduce the elements of parkinsonism. They have anticholinergic and local anesthetic effects. They are quickly excreted from the body.
Cons of antihistamines are short term therapeutic effect(4-6 hours), the need to change the drug during long-term therapy due to a decrease in its therapeutic activity and a wide range of side effects, such as: drowsiness, visual impairment, dry mouth, constipation, headache, urinary retention, tachycardia and lack of appetite. They do not have additional anti-allergic effect. Interact with other drugs.
The drugs in this group are well suited for quickly achieving an effect when it is necessary to treat acute allergic manifestations, for example, urticaria, seasonal rhinitis, or an allergic reaction to food.
The second generation of antihistamines, or H1 antagonists, which entered the market at the end of the 70s of the last century, are structurally related to H1 receptors, therefore they are devoid of the spectrum of side effects inherent in 1st generation drugs and a much wider range of applications is available to them.
These include:
- clarisens
- claridol
- lomilan
- claritin
- kestin
- rupafin
- lorahexal
Their mechanism of action is carried out by the accumulation of active antihistamine metabolites in the blood in a sufficient and long-term concentration. The active substances do not cross the blood-brain barrier, acting on the mast cell membrane, so the risk of drowsiness is minimized.
- physical and mental activity does not subside
- the duration of exposure is up to 24 hours, so it is enough to take most drugs once a day
- when treatment is stopped, the therapeutic effect lasts a week
- not addictive
- active substances are not absorbed in the gastrointestinal tract
- have a cardiotoxic effect, as they block the potassium channels of the heart;
prolonged therapeutic effect
negative effect on the liver and heart
Antihistamines of the 2nd generation are used to relieve acute and prolonged allergic diseases, mild bronchial asthma, and chronic idiopathic urticaria. Contraindicated in the elderly, patients with cardiovascular problems and diseases of the kidneys and liver. Require constant monitoring of cardiac activity.
- zyrtec (cetirizine)
- telfast (fexofenadine)
- trexil (terfenadine)
- hismanal (astemizole)
- erius (desloratadine)
- semprex (crivastin)
- allergodil (acelastin)
advanced modern drugs have a significant duration of action - from half to two days, after completion of treatment, they have an inhibitory effect on histamine for 6-8 weeks.
- have no systemic significant side effects
- indicated for all age groups - some of them are classified as over-the-counter drugs
- suitable for activities that require a high concentration of attention
- indicated for the prevention of allergic diseases
- not addictive
- do not differ, with rare exceptions, in significant drug interactions
for trexil (terfenadine) and astimizan (astemizole), cases of serious cardiotoxic side effects have been described.
if the drugs are used incorrectly, dizziness, nausea, skin flushing, reactions from the gastrointestinal tract are likely;
selectively, this group of drugs should be approached by people with kidney and liver problems.
The use of the latest generation of antihistamines is justified for all population groups without exception during long-term therapy of allergic diseases - atopic dermatitis, perennial allergic rhinitis, atopic syndrome, chronic urticaria, contact dermatitis and others.
Zyrtec (cetirizine) and Claritin (loratadine) are considered the best antihistamines today. The safe profiles of these drugs are great for all age groups, especially children, as they reduce the risk of future allergic reactions.
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I have finally found the answer to a question that has been bugging me for a long time.
I have long noticed that with exacerbations of seasonal allergies, all these expensive and sophisticated antihistamines of the latest generation, which can be taken only once every 24 or even 48 hours, for some reason help me much worse than budget diazolin. I thought that the matter was in the individual characteristics of the body, but it turned out that several acquaintances had the same situation. It turns out that first-generation drugs stop better acute attacks, and the latest generation drugs are more suitable for the treatment of chronic allergies? But after all, even during a short-term allergy, you don’t feel like drinking handfuls of pills and pecking at work ... Well, one more confirmation of the common truth that you need to contact a specialist for a competent appointment.
I have been using Claritin all my life as an antihistamine, and I am completely satisfied with it - it relieves symptoms quickly, does not pull me to sleep, I drink calmly and drive. There are now, of course, more fashionable and new means, for example, the zodak, but I am somehow inclined to trust a time-tested tool, and why change something that already helps? In general, of course, first of all, it is necessary to identify the allergen itself, and, based on this, build a treatment regimen, and it is better, of course, after consulting with a specialist ...
Our magazine contains the most complete information on dermatological diseases. We especially pay attention to the symptoms, causes and treatment.
The most effective antihistamines for children and adults - a list of medicines with instructions and prices
A small number of people were lucky enough to never experience allergic reactions in their lives. Most people have to deal with them from time to time. Effective antihistamines will help to cope with allergies for both an adult and a child. These tools help eliminate negative reactions on the body for certain stimuli. There is a wide range of anti-allergic drugs on the market. It is desirable for every person to be able to understand them.
What are antihistamines
These are drugs whose work is aimed at suppressing the action of free histamine. This substance is released from the connective tissue cells that enter the immune system when an allergen enters the human body. When histamine interacts with certain receptors, swelling, itching, and rashes begin. All of these are symptoms of an allergy. The drugs with antihistamine effect block the aforementioned receptors, alleviating the patient's condition.
Indications for use
You must be prescribed antihistamines by a doctor, having made an accurate diagnosis. As a rule, their administration is advisable in the presence of such symptoms and diseases:
- early atopic syndrome in a child;
- seasonal or year-round rhinitis;
- negative reaction to plant pollen, animal hair, household dust, some medications;
- severe bronchitis;
- angioedema;
- anaphylactic shock;
- food allergies;
- enteropathy;
- bronchial asthma;
- atopic dermatitis;
- conjunctivitis caused by exposure to allergens;
- chronic, acute and other forms of urticaria;
- allergic dermatitis.
Antihistamines - list
There are several generations of antiallergic drugs. Their classification:
- New generation drugs. The most modern medicines. They act very quickly, and the effect of their use lasts for a long time. Block H1 receptors, suppressing allergy symptoms. Antihistamines in this group do not worsen the functioning of the heart, therefore they are considered one of the safest.
- 3rd generation drugs. Active metabolites with very few contraindications. They provide a fast stable result, they are gentle on the heart.
- 2nd generation drugs. Not sedative drugs. They have a small list side effects put a lot of stress on the heart. Do not affect mental or physical activity. Antiallergic drugs of the second generation are often prescribed for the appearance of a rash, itching.
- 1st generation drugs. Sedative drugs operating up to several hours. Well eliminate the symptoms of allergies, but have many side effects, contraindications. From their use always tends to sleep. At the present time, such drugs are prescribed very rarely.
New generation antiallergic drugs
It is not possible to list all the drugs in this group. Let's take a look at some of the best ones. This list opens with the following drug:
- name: Fexofenadine (analogues - Allegra (Telfast), Fexofast, Tigofast, Altiva, Fexofen-Sanovel, Kestin, Norastemizol);
- action: blocks H1 - histamine receptors relieves all allergy symptoms;
- pluses: acts quickly and for a long time, is available in tablets and suspensions, is well tolerated by patients, does not have too many side effects, is dispensed without a prescription;
- cons: not suitable for children under six years of age, pregnant women, nursing mothers, incompatible with antibiotics.
Another drug that deserves attention:
- name: Levocetirizine (analogues - Aleron, Zilola, Alerzin, Glenset, Aleron Neo, Rupafin);
- action: antihistamine, blocks H1 receptors, reduces vascular permeability, has antipruritic and antiexudative effects;
- pluses: there are tablets, drops, syrup on sale, the drug acts in just a quarter of an hour, there are not many contraindications, there is compatibility with many drugs;
- cons: a wide range of strong side effects.
- name: Desloratadine (analogues - Lordes, Allergostop, Alersis, Fribris, Edem, Eridez, Alergomax, Erius);
- action: antihistamine, antipruritic, decongestant, relieves rash, runny nose, nasal congestion, reduces bronchial hyperactivity;
- pluses: the new generation allergy medicine is well absorbed and works quickly, relieves allergy symptoms for a day, does not have a negative effect on the central nervous system and reaction rate, does not harm the heart, joint use with other drugs is allowed;
- cons: not suitable for pregnancy and lactation, prohibited for children under 12 years of age.
Antihistamine 3 generations
The following drug is popular and has many good reviews:
- name: Desal (analogues - Ezlor, Nalorius, Elyseus);
- action: antihistamine, relieves swelling and spasms, relieves itching, rash, allergic rhinitis;
- pluses: it is available in tablets and solution, does not give a sedative effect and does not affect the rate of reactions, it works quickly and acts for about a day, it is quickly absorbed;
- cons: bad effect on the heart, many side effects.
Experts respond well to this drug:
- name: Suprastinex;
- action: antihistamine, prevents the appearance of allergic manifestations and facilitates their course, helps with itching, peeling, sneezing, swelling, rhinitis, lacrimation;
- pluses: it is available in drops and tablets, there is no sedative, anticholinergic and antiserotonergic effect, the drug acts in an hour and continues to work for a day;
- cons: there are a number of strict contraindications.
The group of third-generation drugs also includes the following:
- name: Ksizal;
- action: pronounced antihistamine, not only relieves allergy symptoms, but also prevents their occurrence, reduces the permeability of vascular walls, fights sneezing, lacrimation, edema, urticaria, inflammation of the mucous membranes;
- pluses: sold in tablets and drops, does not have a sedative effect, is well absorbed;
- cons: has a wide list of side effects.
2nd generation antiallergenic drugs
A well-known series of drugs, represented by tablets, drops, syrups:
- name: Zodak;
- action: prolonged anti-allergic, helps against itching, skin peeling, relieves swelling;
- pluses: subject to dosages and rules of administration, it does not cause drowsiness, quickly begins to act, is not addictive;
- cons: prohibited for pregnant women and children.
The next second generation drug:
- name: Cetrin;
- action: antihistamine, well helps with edema, hyperemia, itching, peeling, rhinitis, urticaria, reduces capillary permeability, relieves spasms;
- pluses: there are drops and syrup on sale, low cost, lack of anticholinergic and antiserotonin effects, if the dosage is observed, it does not affect concentration, is not addictive, side effects are extremely rare;
- cons: there are a number of strict contraindications, an overdose is very dangerous.
Another very good drug this category:
- name: Lomilan;
- action: systemic blocker of H1 receptors, relieves all allergy symptoms: itching, peeling, swelling;
- pluses: does not affect the heart and central nervous system, is completely excreted from the body, helps to overcome allergies well and quickly, suitable for continuous use;
- cons: many contraindications and side effects.
Means of the 1st generation
Antihistamines of this group appeared a very long time ago and are now used less often than others, however, they deserve attention. Here is one of the most famous:
- name: Diazolin;
- action: antihistamine, blocker of H1 receptors;
- pros: gives anesthetic effect, acts for a long time, helps well with dermatoses with skin itching, rhinitis, cough, food and drug allergies, insect bites, is cheap;
- cons: there is a moderately pronounced sedative effect, many side effects, contraindications.
This one also belongs to the drugs of the 1st generation:
- name: Suprastin;
- action: anti-allergic;
- pluses: available in tablets and ampoules;
- cons: a pronounced sedative effect, the effect does not last long, there are a lot of contraindications, side effects.
The last member of this group:
- name: Fenistil;
- action: histamine blocker, antipruritic;
- pluses: available in the form of a gel, emulsion, drops, tablets, relieves skin irritation well, relieves pain a little, inexpensive;
- cons: the effect after application passes quickly.
Allergy pills for children
Most antihistamines have strict age contraindications. The question would be quite reasonable: how to treat very small allergies, who suffer at least as often as adults? As a rule, children are prescribed drugs in the form of drops, suspensions, and not tablets. Means approved for the treatment of infants and persons under 12 years of age:
- Diphenhydramine;
- Fenistil (drops are suitable for babies older than a month);
- Peritol;
- Diazolin;
- Suprastin (suitable for babies);
- Clarotadine;
- Tavegil;
- Tsetrin (suitable for newborns);
- Zyrtec;
- Claricens;
- Cinnarizine;
- Loratadine;
- Zodak;
- Claritin;
- Erius (allowed from birth);
- Lomilan;
- Fenkarol.
Mechanism of action of antihistamines
Under the action of an allergen, an excess of histamine is produced in the body. When it is associated with certain receptors, negative reactions are caused (edema, rash, itching, runny nose, conjunctivitis, etc.). Antihistamines reduce the release of this substance into the blood. In addition, they block the action of H1-histamine receptors, thereby preventing them from binding and reacting with histamine itself.
Side effects
Each drug has its own list. The specific list of side effects also depends on which generation the remedy belongs to. Here are a few of the most common:
- headache;
- drowsiness;
- confusion;
- decreased muscle tone;
- fast fatiguability;
- constipation;
- concentration disorders;
- blurred vision;
- abdominal pain;
- dizziness;
- dry mouth.
Contraindications
Each antihistamine drug has its own list, specified in the instructions. Almost every one of them is forbidden to be taken by pregnant girls and nursing mothers. In addition, the list of contraindications for therapy may include:
- individual intolerance to the components;
- glaucoma;
- stomach or duodenal ulcer;
- prostate adenoma;
- obstruction of the bladder;
- childhood or old age;
- diseases of the lower respiratory tract.
Best Allergy Remedies
TOP 5 most effective drugs:
- Erius. fast acting medicine, well eliminating runny nose, itching, rashes. It costs expensive.
- Eden. Drug with desloratadine. Does not give a hypnotic effect. It copes well with lacrimation, itching, swelling.
- Zyrtec. A drug based on cetirizine. Fast acting and efficient.
- Zodak. Excellent medicine from allergies, instantly eliminating symptoms.
- Tsetrin. A drug that rarely gives side effects. Quickly eliminates allergy symptoms.
The price of antihistamines
Name of the drug, form of release, volume
Approximate cost in rubles
Suprastin, tablets, 20 pcs.
Zyrtec, drops, 10 ml
Fenistil, drops, 20 ml
Erius, tablets, 10 pcs.
Zodak, tablets, 30 pcs.
Claritin, tablets, 30 pcs.
Tavegil, tablets, 10 pcs.
Cetrin, tablets, 20 pcs.
Loratadine, tablets, 10 pcs.
Video: Antiallergic drugs for children
Margarita, 28 years old
Since childhood, spring has been a terrible period for me. I just tried not to leave the house, there was not a single photo where I was on the street. When it bothered me, I turned to an allergist. He prescribed me the drug Cetrine. Taking it, I calmly walked, not reacting to flowering plants, other irritants. There were no side effects from the drug.
Christina, 32 years old
I am allergic to household and other types of dust. Houses are perfectly clean, but on the street or at a party only medicines save. At first I took Erius, but the price of this antihistamine bites. I changed it to Desloratadine. Works the same, but much cheaper. This medicine helps me perfectly, one tablet is enough for a day.
The information presented in the article is for informational purposes only. The materials of the article do not call for self-treatment. Only a qualified doctor can make a diagnosis and make recommendations for treatment based on individual features specific patient.
Allergy medicines 4 generations
4th generation antihistamines are the latest tools aimed at enhancing the effectiveness of the fight against allergies. Their hallmark is the duration of the therapeutic effect and the minimum of side effects.
What is histamine?
Histamine is a complex organic substance that is part of many tissues and cells. It is located in special mast cells - histiocytes. This is the so-called passive histamine.
IN special conditions passive histamine becomes active. Thrown into the blood, it spreads throughout the body and has a negative effect on it. This transition occurs under the influence of:
- traumatic lesions;
- stress
- infectious diseases;
- actions of drugs;
- malignant and benign neoplasms;
- chronic diseases;
- removal of organs or their parts.
Active histamine can enter the body with both food and water. Most often this occurs when eating food of animal origin in a stale form.
How does the body react to the appearance of free histamine?
The transition of histamine from a bound state to a free one creates the effect of a viral effect.
For this reason, flu and allergy symptoms are often similar. In this case, the following processes occur in the body:
- Spasms of smooth muscles. Most often they occur in the bronchi and intestines.
- Adrenaline rush. This entails an increase in blood pressure, increased heart rate.
- Increasing production digestive enzymes and mucus in the bronchi and nasal cavity.
- Narrowing of large and expansion of small blood vessels. This causes swelling of the mucous membrane, redness of the skin, the appearance of a rash, a sharp decrease in pressure.
- The development of anaphylactic shock, which is accompanied by convulsions, loss of consciousness, vomiting, a sharp drop in pressure.
Antihistamines and their action
The most effective way to combat histamine are special drugs that reduce the level of this substance in a free active state.
Ever since the first medications Allergy control, four generations of antihistamines have been released. In connection with the development of chemistry, biology and pharmacology, these drugs have been improved, their effect has increased, and contraindications and undesirable consequences decreased.
Representatives of antihistamines of all generations
In order to evaluate the latest generation drugs, the list should start with older drugs.
- First generation: Diphenhydramine, Diazolin, Mebhydrolin, Promethazine, Chloropyramine, Tavegil, Diphenhydramine, Suprastin, Peritol, Pipolfen, Phencarol. All these drugs have a strong sedative and even hypnotic effect. Their main mechanism of action is the blocking of H1 receptors. The duration of their action is in the range of 4 to 5 hours. The antiallergic effect of these drugs can be called good. However, they have too much effect on the entire body. Side effects of such drugs are: dilated pupils, dry mouth, vagueness of the visual picture, constant sleepiness, weakness.
- Second generation: Doxylamine, Hifenadine, Clemastine, Cyproheptadine, Claritin, Zodak, Fenistil, Gistalong, Semprex. At this stage in the development of pharmaceuticals, drugs appeared that did not have a sedative effect. In addition, they no longer contain the same side effects. They do not have an inhibitory effect on the psyche, and also do not cause drowsiness. They are accepted not only allergic manifestations from the respiratory system, but also with skin reactions, for example, urticaria. The disadvantage of these agents was the cardiotoxic effect of their ingredients.
- Third generation: Akrivastine, Astemizol, Dimetinden. These drugs have improved antihistamine capabilities and a small set of contraindications and side effects. In the aggregate of all properties, they are no less effective than 4th generation drugs.
- Fourth generation: Cetirizine, Desloratadine, Fenspiride, Fexofenadine, Loratadine, Azelastine, Xyzal, Ebastin. Antihistamines of the 4th generation are able to block H1- and H2-histamine receptors. This reduces the body's reactions with the mediator histamine. As a result, the allergic reaction weakens or does not appear at all. The likelihood of bronchospasm is also reduced.
The best of the latest generation
The best 4th generation antihistamines are characterized by a long therapeutic effect and a small number of side effects. They do not suppress the psyche and do not destroy the heart.
- Fexofenadine is very popular. It is characterized by the versatility of exposure, so it can be used for all types of allergies. However, it is prohibited for children under 6 years of age.
- Cetirizine is more suitable for the treatment of allergies that manifest on the skin. It is especially recommended for hives. The action of Cetirizine appears 2 hours after ingestion, but the therapeutic effect lasts all day. So with moderate allergy attacks, it can be taken 1 time per day. The drug is often recommended for the treatment of childhood allergies. Long-term use of cetirizine in children suffering from early atopic syndrome significantly reduces the further negative development of diseases of allergic genesis.
- Loratadine has a particularly significant therapeutic effect. This fourth-generation drug can rightfully top the list of leaders.
- Xyzal well blocks the release of inflammatory mediators, which allows you to get rid of allergic reactions for a long time. It is better to use it for bronchial asthma and seasonal allergies to pollen.
- Desloratadine can be classified as one of the most popular antihistamines for all age groups. At the same time, it is rightfully considered one of the safest, with almost no contraindications and undesirable effects. However, it is characterized by at least a small, but still sedative effect. However, this effect is so small that it practically does not affect the rate of human reaction and the activity of the heart.
- Desloratadine is most commonly prescribed for patients with pollen allergies. It can be used both seasonally, that is, during the period of maximum risk, and in other periods. With success, this drug can be used in the treatment of conjunctivitis and allergic rhinitis.
- Levocetirizine, also known as Suprastinex and Caesera, is considered an excellent remedy for pollen allergies. In addition, these drugs can be used for conjunctivitis and allergic rhinitis.
Thus, fourth-generation antihistamines can be used while driving and performing other work that requires a good response. They usually do not interact with other medications, including antibiotics. This allows them to be taken in the treatment of inflammatory diseases.
Because these drugs do not interfere with behavior, thought processes, or adverse effects on the heart, they are generally well tolerated by patients.
In addition, they usually do not interact synergistically with other drugs.
If you notice redness, rashes and swelling of the skin, then you need to contact an allergist to prescribe you antihistamines for skin allergies.
Allergy is an increased reaction of our body to certain environmental factors: drugs, pollen, household chemicals, dust and others.
Clinical picture
WHAT DOCTORS SAY ABOUT EFFECTIVE ALLERGY TREATMENTS
Vice-President of the Association of Children's Allergists and Immunologists of Russia. Pediatrician, allergist-immunologist. Smolkin Yuri Solomonovich
Practical medical experience: more than 30 years
According to the latest WHO data, it is allergic reactions in the human body lead to the occurrence of most fatal diseases. And it all starts with the fact that a person has an itchy nose, sneezing, runny nose, red spots on the skin, in some cases suffocation. 7 million people die each year due to allergies , and the scale of the lesion is such that the allergic enzyme is present in almost every person. Unfortunately, in Russia and the CIS countries, pharmacy corporations sell expensive drugs that only relieve symptoms, thereby putting people on one drug or another. That is why in these countries there is such a high percentage of diseases and so many people suffer from "non-working" drugs. |
This reaction is manifested by itching of the skin, its redness, rash and swelling, conjunctivitis of the eyes, tearing, allergic rhinitis and cough.
Skin rashes on the arms, legs, body and face work well with many antihistamines for skin allergies, cheap domestic and expensive imported.
Allergodermatosis(reaction of the skin) is most often treated with drugs in tablets, because external manifestations on the skin are provoked by internal changes.
In this article, we will analyze which antihistamine is better, which modern medicine against skin rashes helps well and will not cause strong side effects, we will find out a list of inexpensive analogues and generics.
Signs of a skin allergy
The main causes that cause allergic skin rashes are:
IMPORTANT! If the reason skin rashes not eliminated, then effective treatment is impossible in principle. For example, with food allergies, you need to remove those foods that provoke an increased reaction of the body. If the cause is not identified and treated, even an increase in the dose of the allergy medicine will not be able to cope with the symptoms.
If the symptoms appear brightly, then you need to take a good anti-allergic agent that works in a complex way for all symptoms, and not just for skin ones.
List of antihistamines for skin allergies
If you have a skin reaction to an allergen, then you can’t independently compile a list and prices of medicines in alphabetical order that help with an allergic rash and which you should try on yourself. You must contact the experts.
At an appointment with an allergist, a dermatologist, patients ask: “Advise what antiallergic drugs to take? What are the names of effective anti-allergic drugs for itchy skin?
The doctor will not advise the first one that comes across, he can help the allergic person when he conducts a comprehensive examination.
The doctor is obliged to conduct a conversation with an allergic person, learn about other diseases, drug intolerance, and be sure to conduct an examination for the cause of the disease.
Only after that, the doctor can say the name of the antihistamine drug, which can help in the treatment of skin allergies, the most powerful in a particular case.
Despite the fact that allergic dermatosis manifests itself externally, it is necessary to treat it from the inside.
Why is it important to know? Because you need to choose the right dosage form of the drug, that is, first of all, use not external medicines (cream, ointment), but drugs in the form of tablets, drops and solutions.
The choice of medicines for skin allergies today is huge: there are good Russian medicines, known since Soviet times, as well as modern anti-allergic drugs that do not cause drowsiness.
All antihistamines interfere with the production of histamine and block the development process. the following symptoms: redness, itching, swelling of the skin, and also normalize the pressure and breathing of the patient: block spasms in the bronchi and swelling of the larynx. sign strong remedy is also a decrease in lacrimation and redness of the eye proteins and eyelids, the disappearance of allergic cough and runny nose.
1st generation antihistamines
The first generation of antihistamines in our time are prescribed very rarely. They have a number common features: drugs are inexpensive, but causing side effects that seriously affect the body of an allergic person and his lifestyle.
Common features of this group of antihistamines:
- Low cost (the main price tag most often does not exceed 300 rubles);
- A short effect (you need to drink them several times in one day) and quick addiction (they need to be alternated with other drugs from this group every couple of weeks).
Symptoms of the use of first-generation antihistamines:
All these side effects complicate the current lifestyle and daily routine of the patient. These antihistamines can make a person less mobile.
Antihistamines from this group are not popular, except for Suprastin, a cheap drug from the list of essential drugs enshrined at the level of law as vital. It is better to drink these drugs for adults, as they have less side effects. Consider them in the table, which reflects their differences.
| Name | Active substance | Features of the drug | Average price, rub |
| Suprastin | Chloropyramine | Does not cause serious toxic effects on the heart | 128 |
| Tavegil | clemastine | Have serious allergic reactions to ingredients | 159 |
| Diphenhydramine | Diphenhydramine | Strong effect on the central nervous system | 75 |
| Diazolin | Mebhydrolin | Negative effect on the gastrointestinal tract | 69 |
| Peritol | Cyproheptadine | Increases appetite, photosensitivity | 2400 |
| Pipolfen | Promethazine | Decreased intestinal motility, for children from 2 months | 277 |
| Diprazine | Promethazine | Active influence on the nervous system | 1100 |
| Fenkarol | Hifenadine | Weak efficiency | 350 |
We do not recommend taking these antihistamines because of the huge number of contraindications and serious side effects, but you need to know what they are called.
2nd generation antihistamines
With an allergic rash, they often drink second-generation antiallergic drugs, they are universal (prescribed for many types of allergies). They are not addictive, do not affect the nervous system, which means that there will be no drowsiness and lethargy.
| Name | Active substance | Features of the drug | Average price, rub. |
| Claritin | Loratadine | It is prescribed for children from one year old and the elderly, there are almost no side effects. | 174 |
| Semprex | Akrivastine | It has a short action, but the medicine is safe | 110 |
| Trexil | Terfenadine | The first remedy of the 2nd generation, depresses the cardiac system. It is inexpensive. | 97 |
| Fenistil | Dimetindene maleate | Tablets, gel. Popular tool. | 319 |
| Histalong | Astemizol | Effective in chronic allergies. | There is no information, because it has not been present on the market for a long time |
Most often, Claritin is prescribed from this list, since it is believed that this remedy is safe. But it can be replaced by domestic inexpensive analogue with a similar active substance, which gave it the trade name ("Loratadin"). The price of the latter is much lower. Loratadine is used in the treatment of children, replacing the first-generation drug Ketotifen, an inexpensive drug, but with a large number of side effects.
- Likopid.
- Viferon.
- Derinat.
- Timolin.
- Immunofan.
The antihistamines listed above are not all anti-allergy drugs presented on pharmacy shelves. Their great multitude which is very difficult to understand. The main thing to remember is that a specialist should prescribe this or that drug.
Catad_tema Allergology - Articles
Antihistamines: myths and reality
"EFFICIENT PHARMACOTHERAPY"; No. 5; 2014; pp. 50-56.
T.G. Fedoskova
SSC Institute of Immunology, FMBA of Russia, Moscow
The main drugs that affect the symptoms of inflammation and control the course of diseases of allergic and non-allergic origins include antihistamines.
The article analyzes the debatable points regarding the experience of using modern antihistamines, as well as some of their main characteristics. This will allow a differentiated approach to the choice of the optimal drug in the complex therapy of various diseases.
Keywords: antihistamines, allergic diseases, cetirizine, Cetrin
ANTIHISTAMINES: MYTHS AND REALITY
T.G. Fedoskova
State Science Center Institute of Immunology, Federal medical and Biological Agency, Moscow
Antihistamines belong to main drugs influencing symptoms of inflammation and controlling course of both of allergic and non-allergic diseases. In this paper debatable issues regarding experience of using current antihistamines as well as some of their characteristics are analyzed. It may let to make a differential choice to administer appropriate drugs for a combination therapy of different diseases.
key words: antihistamines, allergic diseases, cetirizine, Cetrine
Type 1 antihistamines (H1-AHP), or type 1 histamine receptor antagonists, are widely and successfully used in clinical practice for over 70 years. They are used as part of symptomatic and basic therapy of allergic and pseudo-allergic reactions, complex treatment of acute and chronic infectious diseases of various origins, as premedication during invasive and radiopaque studies, surgical interventions, for the prevention of side effects of vaccination, etc. In other words, H 1 -AHP is advisable to use in conditions caused by the release of active mediators of inflammation of a specific and non-specific nature, the main of which is histamine.
Histamine has a wide spectrum biological activity realized by activation of cell surface specific receptors. The main depot of histamine in the tissues are mast cells, in the blood - basophils. It is also present in platelets, gastric mucosa, endothelial cells, and brain neurons. Histamine has a pronounced hypotensive effect and is an important biochemical mediator in all clinical symptoms of inflammation of various origins. That is why antagonists of this mediator remain the most popular pharmacological agents.
In 1966, the heterogeneity of histamine receptors was proven. Currently, 4 types of histamine receptors are known - H 1 , H 2 , H 3 , H 4 belonging to the superfamily of receptors associated with G-proteins (G-protein-coupled receptors -GPCRs). Stimulation of H 1 receptors leads to the release of histamine and the realization of inflammation symptoms, mainly of allergic origin. Activation of H 2 receptors increases secretion gastric juice and its acidity. H3 receptors are predominantly present in the organs of the central nervous system (CNS). They function as histamine-sensitive presynaptic receptors in the brain, regulate the synthesis of histamine from presynaptic nerve endings. Recently, a new class of histamine receptors, expressed predominantly on monocytes and granulocytes, H 4 , has been identified. These receptors are present in the bone marrow, thymus, spleen, lungs, liver, and intestines. The mechanism of action of H 1 -AHP is based on reversible competitive inhibition of histamine H 1 receptors: they prevent or minimize inflammatory reactions, preventing the development of histamine-induced effects, and their effectiveness is due to the ability to competitively inhibit the effect of histamine on the loci of specific H 1 receptor zones in effector tissue structures.
Currently, over 150 types of antihistamines are registered in Russia. These are not only H 1 -AGP, but also drugs that increase the ability of blood serum to bind histamine, as well as drugs that inhibit the release of histamine from mast cells. Due to the variety of antihistamines, make a choice between them for their most effective and rational use in specific clinical cases is quite difficult. In this regard, there are debatable points, and often myths are born about the use of H 1 -AHP, which are widely used in clinical practice. In the domestic literature, there are many works on this topic, however, there is no consensus on the clinical use of these drugs (PM).
The myth of three generations of antihistamines
Many are mistaken in thinking that there are three generations of antihistamines. Some pharmaceutical companies are introducing new drugs that have appeared on the market. pharmaceutical market, as AGP of the third - latest - generation. Attempts were made to classify metabolites and stereoisomers of modern AGPs to the third generation. Currently, these drugs are considered to be second-generation antihistamines, since there is no significant difference between them and previous second-generation drugs. According to the Consensus on Antihistamines, it was decided to reserve the name "third generation" to denote future synthesized antihistamines, which are likely to differ from known compounds in a number of key characteristics.
There are many differences between first and second generation AGPs. This is primarily the presence or absence of a sedative effect. Sedative action when taking first-generation antihistamines, 40-80% of patients are subjectively noted. Its absence in individual patients does not exclude the objective negative effect of these drugs on cognitive functions, which patients may not complain about (the ability to drive a car, learn, etc.). Dysfunction of the central nervous system is observed even with the use of minimal doses of these drugs. The effect of first-generation antihistamines on the central nervous system is the same as when using alcohol and sedatives(benzodiazepines, etc.).
Second-generation drugs practically do not penetrate the blood-brain barrier, so they do not reduce the mental and physical activity of patients. In addition, first and second generation antihistamines differ in the presence or absence of side effects associated with stimulation of other types of receptors, the duration of action, and the development of addiction.
The first AGPs - phenbenzamine (Antergan), pyrilamine maleate (Neo-Antergan) began to be used as early as 1942. Subsequently, new antihistamines have appeared for use in clinical practice. Until the 1970s Dozens of compounds belonging to this group of drugs have been synthesized.
On the one hand, there is a large clinical experience use of first-generation antihistamines, on the other hand, these drugs have not been examined in clinical trials corresponding to modern requirements evidence-based medicine.
Comparative characteristics AGP of the first and second generations is presented in Table. 1 .
Table 1.
Comparative characteristics of AGP of the first and second generations
| Properties | First generation | Second generation |
| Sedation and effects on cognition | Yes (in minimum doses) | No in therapeutic doses) |
| Selectivity for H 1 receptors | No | Yes |
| Pharmacokinetic studies | Few | A lot of |
| Pharmacodynamic studies | Few | A lot of |
| Scientific research various doses | No | Yes |
| Studies in newborns, children, elderly patients | No | Yes |
| Use in pregnant women | FDA Category B (diphenhydramine, chlorpheniramine), Category C (hydroxyzine, ketotifen) | FDA Category B (loratadine, cetirizine, levocetirizine), Category C (desloratadine, azelastine, fexofenadine, olopatadine) |
Note. FDA (US Food and Drug Administration) - Food and Drug Administration (USA). Category B - no teratogenic effect of the drug was detected. Category C - studies have not been conducted.
Since 1977, the pharmaceutical market has been replenished with new H 1 -AHPs, which have clear advantages over first-generation drugs and meet modern requirements for AGPs set out in the EAACI (European Academy of Allergology and Clinical Immunology) consensus documents.
The myth about the benefits of the sedative effect of first-generation antihistamines
Even with regard to some of the side effects of first-generation antihistamines, there are misconceptions. The sedative effect of first-generation H1-HPA is associated with the myth that their use is preferable in the treatment of patients with concomitant insomnia, and if this effect is undesirable, it can be leveled by using the drug at night. At the same time, it should be remembered that first-generation antihistamines inhibit the phase of REM sleep, due to which the physiological process of sleep is disturbed, and there is no complete processing of information in sleep. Their use may cause respiratory failure, heart rate which increases the risk of developing sleep apnea. In addition, in some cases, the use of high doses of these drugs contributes to the development of paradoxical excitation, which also negatively affects the quality of sleep. It is necessary to take into account the difference in the duration of the preservation of the antiallergic effect (1.5-6 hours) and the sedative effect (24 hours), as well as the fact that prolonged sedation is accompanied by impaired cognitive functions.
The presence of pronounced sedative properties debunks the myth of the advisability of using first-generation H1-AHP in elderly patients who use these drugs, guided by the prevailing stereotypes of habitual self-treatment, as well as the recommendations of doctors who are not sufficiently informed about pharmacological properties drugs and contraindications to their use. Due to the lack of selectivity of effects on alpha-adrenergic receptors, muscarinic, serotonin, bradykinin and other receptors, a contraindication to the appointment of these drugs is the presence of diseases that are quite common among the elderly patients - glaucoma, benign prostatic hyperplasia, bronchial asthma, chronic obstructive pulmonary disease, etc. . .
The myth about the absence of a place in clinical practice for first-generation antihistamines
Despite the fact that first-generation H1-AHPs (most of them developed in the middle of the last century) are capable of causing known side effects, they are still widely used in clinical practice today. Therefore, the myth that with the advent of the new generation of AHD there is no place left for the previous generation of AHD is invalid. The H 1 -AGP of the first generation has one indisputable advantage - the presence of injectable forms that are indispensable in the provision of emergency care, premedication before carrying out certain types of diagnostic examination, surgical interventions, etc. In addition, some drugs have an antiemetic effect, reduce the state of increased anxiety, and are effective in motion sickness. An additional anticholinergic effect of a number of drugs of this group is manifested in a significant reduction in itching and skin rashes with itchy dermatoses, acute allergic and toxic reactions to food, drugs, insect bites and stings. However, it is necessary to prescribe these drugs with strict consideration of indications, contraindications, severity clinical symptoms, age, therapeutic dosages, side effects. The presence of pronounced side effects and the imperfection of the first generation H 1 -AGP contributed to the development of new second generation antihistamine drugs. The main directions of improvement of drugs were the increase in selectivity and specificity, the elimination of sedation and tolerance to the drug (tachyphylaxis).
Modern H 1 -AGP of the second generation have the ability to selectively affect H 1 receptors, do not block them, but, being antagonists, they transfer them to an “inactive” state without violating their physiological properties, have a pronounced anti-allergic effect, a rapid clinical effect, act long (24 hours), do not cause tachyphylaxis. These drugs practically do not penetrate the blood-brain barrier, therefore, do not cause a sedative effect, cognitive impairment.
Modern H 1 -AGP of the second generation have a significant anti-allergic effect - they stabilize the membrane of mast cells, suppress the release of interleukin-8 induced by eosinophils, granulocyte macrophage colony-stimulating factor (Granulocyte Macrophage Colony-Stimulating Factor. GM-CSF) and a soluble molecule intercellular adhesion 1 (Soluble Intercellular Adhesion Molecule-1, sICAM-1) from epithelial cells, which contributes to greater efficiency in comparison with H 1 -AHP of the first generation in the basic therapy of allergic diseases, in the genesis of which mediators of the late phase play a significant role allergic inflammation.
In addition, an important characteristic of second-generation H1-AHP is their ability to provide an additional anti-inflammatory effect by inhibiting the chemotaxis of eosinophils and neutrophilic granulocytes, reducing the expression of adhesion molecules (ICAM-1) on endothelial cells, inhibiting IgE-dependent platelet activation, and releasing cytotoxic mediators. Many doctors do not pay due attention to this, however, the listed properties make it possible to use such drugs for inflammation not only of an allergic nature, but also of an infectious origin.
The myth of the same safety of all second-generation AHDs
There is a myth among physicians that all second-generation H1-HPAs are similar in their safety. However, in this group of drugs there are differences associated with the peculiarity of their metabolism. They may depend on the variability in the expression of the CYP3A4 enzyme of the liver cytochrome P 450 system. Such variability may be due to genetic factors, diseases of the organs of the hepatobiliary system, simultaneous reception a number of drugs (macrolide antibiotics, some antimycotic, antiviral drugs, antidepressants, etc.), products (grapefruit) or alcohol that have an inhibitory effect on the oxygenase activity of the CYP3A4 cytochrome P450 system.
Among the H1-AGP of the second generation, there are:
Rice. 1. Features of the metabolism of H 1 -AGP of the second generation
The advantages of active metabolites, the intake of which is not accompanied by an additional burden on the liver, are obvious: the speed and predictability of the development of the effect, the possibility joint reception with various drugs and foods that are metabolized with the participation of cytochrome P450.
The myth of more high efficiency each new AGP
The myth that the new H1-AGP agents that have appeared in recent years are obviously more effective than the previous ones has also not been confirmed. The works of foreign authors indicate that second-generation H1-AHP, for example, cetirizine, have a more pronounced antihistamine activity than second-generation drugs that appeared much later (Fig. 2).
Rice. 2. Comparative antihistamine activity of cetirizine and desloratadine on the effect on the skin reaction caused by the administration of histamine within 24 hours 
It should be noted that among the H 1 -AGP of the second generation, researchers assign a special place to cetirizine. Developed in 1987, it was the first original highly selective H1 receptor antagonist based on the pharmacologically active metabolite of the previously known first-generation antihistamine, hydroxyzine. Until now, cetirizine remains a kind of standard of antihistamine and antiallergic action, used for comparison in the development of the latest antihistamine and antiallergic drugs. There is an opinion that cetirizine is one of the most effective antihistamine H 1 drugs, it has been used more often in clinical trials, the drug is preferable for patients who respond poorly to therapy with other antihistamines.
The high antihistamine activity of cetirizine is due to the degree of its affinity for H 1 receptors, which is higher than that of loratadine. It should also be noted the significant specificity of the drug, since even at high concentrations it does not have a blocking effect on serotonin (5-HT 2), dopamine (D 2), M-cholinergic receptors and alpha-1-adrenergic receptors.
Cetirizine meets all the requirements for modern second generation antihistamines and has a number of features. Among all known antihistamines, the active metabolite cetirizine has the smallest volume of distribution (0.56 l/kg) and provides full employment of H1 receptors and the highest antihistamine effect. The drug is characterized by a high ability to penetrate the skin. 24 hours after taking a single dose, the concentration of cetirizine in the skin is equal to or exceeds the concentration of its content in the blood. However, after course treatment The therapeutic effect lasts up to 3 days. The pronounced antihistamine activity of cetirizine favorably distinguishes it among modern antihistamines (Fig. 3).
Rice. 3. Efficacy of a single dose of second-generation H 1 -AHP in suppressing histamine-induced whealing over 24 hours in healthy men 
Myth about high cost all modern AGP
Any chronic illness not immediately amenable to even adequate therapy. It is known that insufficient control over the symptoms of any chronic inflammation leads not only to a deterioration in the patient's well-being, but also to an increase in the total cost of treatment due to an increase in the need for drug therapy. The selected drug should have the most effective therapeutic effect and be affordable. Physicians who remain committed to prescribing first-generation H1-AHP explain their choice by referring to yet another myth that all second-generation antihistamines are much more expensive than first-generation drugs. However, in addition to the original drugs on the pharmaceutical market, there are generics, the cost of which is lower. For example, at present, 13 generics are registered from cetirizine drugs in addition to the original one (Zyrtec). The results of pharmacoeconomic analysis presented in Table. 2, testify to the economic feasibility of using Cetrin, a modern second-generation AGP.
Table 2.
Results of comparative pharmacoeconomic characteristics of H1-AGP of the first and second generations
| A drug | Suprastin 25 mg № 20 | Diazolin 100 mg №10 | Tavegil 1 mg № 20 | Zyrtec 10 mg No. 7 | Cetrin 10 mg № 20 |
| Average market value of 1 pack | 120 rub. | 50 rub. | 180 rub. | 225 rub. | 160 rub. |
| Multiplicity of reception | 3 r/day | 2 r / day | 2 r / day | 1 r / day | 1 r / day |
| The cost of 1 day of therapy | 18 rub. | 10 rub. | 18 rub. | 32 rub. | 8 rub. |
| Cost of 10 days of therapy | 180 rub. | 100 rub. | 180 rub. | 320 rub. | 80 rub. |
The myth that all generics are equally effective
The question of the interchangeability of generics is relevant when choosing the optimal modern antihistamine drug. Due to the variety of generics on the pharmacological market, a myth has arisen that all generics act approximately the same, so you can choose any, focusing primarily on price.
Meanwhile, generics differ from each other, and not only pharmacoeconomic characteristics. The stability of the therapeutic effect and therapeutic activity reproduced drug are determined by the features of technology, packaging, quality of active substances and excipients. The quality of the active substances of drugs from different manufacturers can vary significantly. Any change in the composition of excipients may contribute to a decrease in bioavailability and the occurrence of side effects, including hyperergic reactions. different nature(toxic, etc.). Generic must be safe to use and equivalent original drug. Two medicinal products are considered to be bioequivalent if they are pharmaceutically equivalent, have the same bioavailability and, when administered at the same dose, are similar, providing adequate efficacy and safety. As recommended World Organization health care, the bioequivalence of a generic should be determined in relation to the officially registered original drug. The study of bioequivalence is one of the stages in the study of therapeutic equivalence. The FDA (Food and Drug Administration - Food and Drug Administration (USA)) annually publishes and publishes the "Orange Book" with a list of drugs that are considered therapeutically equivalent to the original. Thus, any doctor can make the optimal choice of a safe antihistamine drug, taking into account all the possible characteristics of these drugs.
One of the highly effective generics of cetirizine is Cetrin. The drug acts quickly, for a long time, has a good safety profile. Cetrin is practically not metabolized in the body, the maximum serum concentration is reached one hour after ingestion, with prolonged use it does not accumulate in the body. Cetrin is available in 10 mg tablets, indicated for adults and children from 6 years of age. Cetrin is completely bioequivalent to the original drug (Fig. 4).
Rice. 4. The average dynamics of the concentration of cetirizine after taking the compared drugs 
Cetrin is successfully used as part of the basic therapy of patients with allergic rhinitis with sensitization to pollen and household allergens, allergic rhinitis associated with atopic bronchial asthma, allergic conjunctivitis, urticaria, including chronic idiopathic urticaria, pruritic allergic dermatoses, angioedema, as well as symptomatic therapy for acute viral infections in patients with atopy. When comparing the effectiveness of cetirizine generics in patients with chronic urticaria when using Cetrin, best results(Fig. 5) .
Rice. 5. Comparative evaluation of the clinical efficacy of cetirizine preparations in patients with chronic urticaria 
Patriotic and Foreign experience use of Cetrin indicates its high therapeutic efficacy V clinical situations when the use of H 1 antihistamines of the second generation is indicated.
Thus, when choosing the optimal H 1 -antihistamine drug from all drugs on the pharmaceutical market, one should not be based on myths, but on selection criteria that include maintaining a reasonable balance between efficacy, safety and availability, the presence of a convincing evidence base, and high quality production. .
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There are three (according to some authors - four) generations of antihistamines. The first includes drugs that, in addition to antiallergic, also have a sedative / hypnotic effect. The second includes drugs with a minimally pronounced sedative effect and a powerful antiallergic effect, but in some cases causing serious, life-threatening arrhythmias. Antihistamine drugs of the new - third - generation are metabolic products (metabolites) of second-generation drugs, and their effectiveness is 2-4 times higher than that of their predecessors. They have a number of unique positive properties and do not cause such side effects as drowsiness and negative impact on the heart. It is about the drugs of the third generation that will be discussed in this article.
New (third) generation antihistamines: mechanism of action and effects
Drugs in this group act exclusively on H1-histamine receptors, that is, they have a selective action. Their antiallergic effect is also provided by the following mechanisms of action. So, these drugs:
- inhibit the synthesis of mediators of systemic allergic inflammation, including chemokines and cytokines;
- reduce the number and disrupt the function of adhesion molecules;
- inhibit chemotaxis (the process of release of leukocytes from the vascular bed into the damaged tissue);
- inhibit the activation of allergy cells, eosinophils;
- inhibit the formation of superoxide radical;
- reduce the increased reactivity (hyperreactivity) of the bronchi.
All of the above mechanisms of action provide powerful anti-allergic and, to a certain extent, anti-inflammatory effects: they eliminate itching, reduce the permeability of the capillary wall, swelling and hyperemia of tissues. Do not cause drowsiness, do not have a toxic effect on the heart. They do not bind to cholinergic receptors, therefore, they do not cause such side effects as blurred vision and. They have a high security profile. It is thanks to these properties that new generation antihistamines can be recommended for long-term treatment of a number of patients.
Side effects
As a rule, these drugs are well tolerated by patients. However, occasionally, against the background of their use, the following undesirable effects may develop:
- fatigue;
- dry mouth (very rare);
- hallucinations;
- drowsiness, insomnia, agitation;
- , heartbeat;
- nausea, vomiting, discomfort in the epigastrium, in isolated cases -;
- muscle pain;
- allergic reactions: skin rash, with or without it, shortness of breath, Quincke's edema, anaphylactic reactions.
Indications and contraindications for the use of third-generation antihistamines
Foods can cause food allergies and cause illness. Indications for the use of drugs in this group are:
- allergic rhinitis (both year-round and seasonal);
- (also, both seasonal and year-round);
- chronic;
- allergic;
New generation antihistamines are contraindicated only in case of individual hypersensitivity the patient's body to them.
Representatives of new generation antihistamines
This group of medicines includes:
- fexofenadine;
- cetirizine;
- Levocetirizine;
- Desloratadine.
Let's consider each of them in more detail.
Fexofenadine (Altiva, Telfast, Tigofast, Fexofast, Fexofen-Sanovel)
Release form: film-coated tablets of 120 and 180 mg.
Pharmacologically active metabolite of the second generation drug, terfenadine.
After ingestion, it is rapidly absorbed in the digestive tract, reaching a maximum concentration in the blood after 1-3 hours. Almost does not bind to blood proteins, does not penetrate the blood-brain barrier. The half-life is 11-15 hours. It is excreted mainly with bile.
The antiallergic effect of the drug develops within 60 minutes after a single dose, within 6 hours the effect increases and persists throughout the day.
Adults and children over 12 years of age are recommended to take 120-180 mg (1 tablet) once a day, before meals. The tablet should be swallowed without chewing with 200 ml of water. The course of treatment is determined individually depending on the characteristics of the course of the disease. Even after regular use of fexofenadine for 28 days, there were no signs of intolerance.
For patients suffering from severe or, the drug should be used with caution.
During pregnancy should not be used, since clinical studies in this category of patients have not been conducted.
The drug passes into breast milk, so nursing mothers should not take it either.
Cetirizine (Allertec, Rolinoz, Tsetrin, Amertil, Zodak, Tsetrinal)
Avoid alcohol while taking antihistamines. Release form: film-coated tablets, oral solution and drops, syrup.
Metabolite of hydroxyzine. The strongest antagonist of H1-histamine receptors.
The use of this drug in average therapeutic doses significantly improves the quality of life of patients suffering from seasonal and chronic allergic rhinitis.
After ingestion, the effect appears after 2 hours and lasts for a day or more.
In patients with impaired renal function, the dose of cetirizine should be adjusted depending on the amount of creatinine clearance: with renal lung failure severity, 10 mg of an antihistamine is prescribed once a day, which is a full dose; moderate degree - 5 mg 1 time per day (half dose); if the creatinine clearance corresponds to a severe degree of renal insufficiency, it is recommended to take 5 mg of cetirizine every other day, and for patients on hemodialysis with end-stage renal failure, taking the drug is completely contraindicated.
Contraindications to the use of cetirizine are also individual hypersensitivity to it and congenital pathology carbohydrate metabolism (glucose-galactose malabsorption syndrome and others).
cetirizine taken in usual doses, can cause such temporary adverse reactions like fatigue, drowsiness, excitation of the central nervous system, dizziness and headache. In some cases, against the background of its reception, dry mouth, disturbance of eye accommodation, difficulty urinating and increased activity of liver enzymes are noted. As a rule, after discontinuation of the drug, these symptoms disappear on their own.
During the period of treatment, you should stop taking.
Persons suffering from convulsive syndrome and epilepsy should take the drug with extreme caution due to increased risk occurrence.
During pregnancy, use if absolutely necessary. Do not take during lactation as it is excreted in breast milk.
Levocetirizine (L-cet, Alerzin, Aleron, Zilola, Cetrilev, Aleron neo, Glentset, Xizal)
Release form: coated tablets, drops for oral intake, syrup (dosage form for children).
A derivative of cetirizine. The affinity for H1-histamine receptors of this drug is several times higher than that of its predecessor.
When taken orally, it is rapidly and completely absorbed, and the degree of absorption does not depend on food intake, however, its rate decreases in the presence of food in the stomach. In some patients, the effect of the drug begins within 12-15 minutes after administration, but in most patients it develops later, after 30-60 minutes. The maximum concentration in the blood is determined after 50 minutes and persists for 48 hours. The half-life is from 6 to 10 hours. Excreted by the kidneys.
In persons suffering from severe renal insufficiency, the half-life of the drug is prolonged.
It is allocated with breast milk.
Adults and children over 6 years of age are recommended to use the tablet form of the drug. 1 tablet (5 mg) is taken orally, without chewing, with enough water. Multiplicity of reception - 1 time per day. If levocetirizine is prescribed in the form of drops, its dose for adult patients and children 6 years of age and older is 20 drops 1 time per day. Children under 6 years of age are prescribed in the form of syrup or drops, the dose of which depends on the age of the child.
Persons with severe renal insufficiency should calculate the creatinine clearance before prescribing the drug. If this value indicates impaired renal function of the first degree, then the recommended dose of the antihistamine drug is 5 mg per day, that is, the full dose. In case of moderate impairment of kidney function, it is 5 mg 1 time in 48 hours, that is, every other day. In severe renal impairment, the drug should be taken at 5 mg 1 time in 3 days.
The duration of the course of treatment varies widely and is selected individually depending on the disease and the severity of its course. So, with hay fever, the course of treatment, as a rule, is 3-6 months, with chronic allergic diseases- up to 1 year, in case of potential contact with an allergen - 1 week.
Contraindications to the use of levocetirizine, in addition to individual intolerance and severe chronic renal failure, are congenital (galactose intolerance, lactase deficiency, and others), as well as pregnancy and lactation.
Side effects are similar to those of other drugs in this group.
Taking levocetirizine, it is strictly contraindicated to drink alcoholic beverages.
Desloratadine (Alersis, Lordes, Trexil neo, Erius, Eden, Alergomax, Allergostop, DS-Lor, Fribris, Eridez)
Presentation: 5 mg film-coated tablets and oral solution containing 0.5 mg of active ingredient per ml (dosage form for children). Some drugs, in particular Allergomax, are also available in the form of a nasal spray.
