Antihistamines of the latest generation of titles list the best. Phencarol to combat allergy symptoms: instructions for use for children

Question: Can antiallergic antihistamines harm a person if taken on a regular basis?

Answer: It is better to pass tests for allergens on the machine "IMEDIS Expert", and further exclude contacts with identified bioresonance test allergens. Also, if possible, it is treated by a bioresonance therapist and for many years to take homeopathic and bioresonance preparations prescribed during the treatment of bioresonance therapy, as well as during exacerbations or during the allergic season, take new-generation antihistamine drugs selected by a bioresonance test or pendulum.

You need to drink new generation antihistamines 1 time per day until the allergy symptoms disappear. If contact with the allergen cannot be avoided, then you will have to take an antihistamine (anti-allergic drug) daily, there is nowhere to go from this, alas. When exposed to an allergen without an antiallergic drug, a severe allergic reaction can develop, which in turn can lead to death, coma, and allergies can also turn into asthma.

There are people who sit on new generations of antihistamines during their lifetime and nothing.

Of course, pills are no sweetie, and antihistamines are no exception. In a state of reaction, do not try to do without them. Allergens will need to be removed from the field of the body on time, and then it may be too late.

Antihistamines

Antihistamines are a group of drugs whose principle of action is based on the fact that they block H1 and H2-histamine receptors. This blocking helps to reduce the reaction of the human body with a special mediator histamine. What are these medicines for? Doctors prescribe them during allergic reactions. Possessing good antipruritic, antispastic, antiserotonin and local anesthetic effects, antihistamines perfectly help with allergies, and also effectively prevent bronchospasm caused by histamine.

In accordance with the time of invention and release on sale, the whole variety of allergy remedies is classified into several levels. Antihistamines are classified into first, second, third and fourth generation drugs. The medicines included in each generation have their own specific features and properties. Their classification is based on the duration of the antihistamine effect, the existing contraindications and side effects. The medicine necessary for treatment must be selected based on the characteristics of each specific case of the disease.

Generations of antihistamines

First generation antihistamines

Preparations of the 1st (first) generation include sedatives. They work at the level of H-1 receptors. The duration of their action is four to five hours, after this period it will be necessary to take a new dose of the drug, and the dose should be large enough. Sedative antihistamines, despite their strong effect, have a number of disadvantages. For example, they can provoke dry mouth, dilated pupils, blurred vision.

Drowsiness and a decrease in tone may occur, which means it is impossible to take these drugs while driving a car and other activities that require a high concentration of attention. They also enhance the effect of taking other sedatives, sleeping pills and pain medications. The effect on the body of alcohol mixed with sedatives is also enhanced. Most first generation antihistamines are interchangeable.

Their use is advisable in case of allergic problems with the respiratory system, for example, when coughing or nasal congestion. It is worth paying attention to the fact that first-generation antihistamines fight cough well. This makes it appropriate to use them in bronchitis.

They will also be useful for those people who suffer from chronic diseases associated with difficulty breathing. Their use is quite effective in bronchial asthma. They can also have a fairly good effect in the treatment of acute allergic reactions. So, for example, their use will be appropriate for urticaria. The most common among them are:

suprastin

diphenhydramine

diazolin

tavegil

Also often on sale you can find peritol, pipolfen and fenkarol.

Second generation antihistamines

Preparations of the 2nd (second) generation are called non-sedative. They do not have such a large list of side effects as the drugs that make up the first generation of antihistamines. These are drugs that do not cause drowsiness and do not reduce brain activity, and also do not have cholinergic effects. A good effect is given by their use in itchy skin and allergic rashes.

However, their significant drawback is the cardiotoxic effect that these drugs can cause. Therefore, non-sedative drugs are prescribed only on an outpatient basis. In no case should they be taken by people suffering from diseases of the cardiovascular system. Names of the most common non-sedative drugs:

trexil

histalong

zodak

semprex

fenistil

claritin

Third generation antihistamines

Antihistamines of the 3rd (third) generation are also otherwise called active metabolites. They have strong antihistamine properties and have virtually no contraindications. The standard set of these drugs includes:

cetrin

zyrtec

telfast

These drugs do not have a cardiotoxic effect, unlike second-generation drugs. Their use gives a positive effect in asthma and acute allergic reactions. They are also effective in the treatment of dermatological diseases. Quite often, third-generation antihistamines are prescribed by doctors for psoriasis.

New generation drugs are the most effective and harmless antihistamines. They are non-addictive, safe for the cardiovascular system, and also have a long period of action. They belong to the fourth generation of antihistamines.

Fourth generation antihistamines

Preparations of the 4th (fourth) generation have a small list of contraindications, which are mainly pregnancy and childhood, but, nevertheless, it is worth reading the instructions and consulting with a specialist before starting treatment. The list of these drugs includes:

levocetirizine

desloratadine

fexofenadine

Based on them, a larger number of drugs are produced, which, if necessary, can be purchased at a pharmacy. These include erius, xizal, lordestin, and telfast.

Forms of release of antihistamines

There are several forms of release of drugs that block histamine receptors. In most cases, their most convenient type to use are tablets and capsules. However, on the shelves of pharmacies you can also find antihistamines in ampoules, suppositories, drops and even syrups. The action of each of them is unique, so only a doctor can help you choose the most appropriate form of taking the medicine.

Treatment of children with antihistamines

As you know, children are more prone to allergic diseases than adults. A qualified allergist should select and prescribe drugs for children. Many of them in the list of their contraindications are of children's age, therefore, if necessary, from the application to the preparation of a course of treatment, it is necessary to be especially careful. Children's organisms can react quite sharply to the effects of the drug, so the child's well-being during the period of their use must be monitored very carefully. In case of side effects, the drug should be stopped immediately and consult a doctor.

For the treatment of children, both somewhat outdated medicines and more modern ones are suitable. The drugs that make up the first generation are mainly used to urgently relieve acute allergy symptoms. During long-term use, more modern means are usually used.

Antihistamines are not usually available in special "children's" forms. For the treatment of children, the same drugs are used as for adults, but in smaller doses. Drugs such as zyrtec and ketotifen are usually prescribed from the moment the child reaches the age of six months, all others - from two years. Do not forget that taking medicines by a child should be under the supervision of an adult.

In the case of an illness of a small child, the selection of antihistamines is much more complicated. For newborns, medications that have a slight sedative effect, that is, first-generation drugs, may be suitable. The most commonly used in the treatment of very young children is suprastin. It is safe for both babies and older children, as well as for nursing mothers and pregnant women. Depending on the disease and the condition of the child's body, the doctor may prescribe him tavegil or Phencarol, and in the case of an allergic skin reaction, an antihistamine cream. For infants, the same drugs are suitable as for newborns.

Antihistamines during pregnancy and lactation

Due to the increased production of cortisol in the body of a woman, allergies during the childbearing period are quite rare, but, nevertheless, some women still face this problem. During pregnancy, the intake of absolutely all medications must be agreed with the doctor. This also applies to allergy remedies, which have a fairly wide range of side effects and can harm the child. The use of antihistamines is strictly prohibited in the first trimester of pregnancy; in the second and third trimesters, they can be used, observing, however, the necessary precautions.

Unintentional ingestion of the drug into the child's body is possible not only during pregnancy, but also during breastfeeding. During lactation, the use of antihistamines is highly undesirable and is prescribed only in the most urgent cases. The question of which remedy a nursing woman will use can only be decided by a doctor. Even the newest and most modern medicines can cause irreparable harm, so in any case, do not self-medicate by feeding your baby with your milk.

Side effects of antihistamines

As mentioned earlier, the body of each person is individual, and only a specialist can choose the right remedy for treatment. Taking the wrong medicine for a person and violating the dosage can seriously harm health. The harm of antihistamines can manifest itself in addition to their usual side effects such as drowsiness, runny nose and cough in violation of the timing of ovulation in women, the occurrence of allergic edema and asthma. Therefore, be sure to consult your doctor before you start drinking the medicine, and strictly follow the recommendations for taking it.

Drug treatment of allergies, antihistamines

How antihistamines work

Antihistamines of the "old" and "new" generations

What is the difference between 1st, 2nd and 3rd generation antihistamines

Fundamentals of drug therapy

There is such a substance - histamine. It is released during an allergic reaction and is responsible for the development of bad symptoms, from skin manifestations to very severe life-threatening reactions, such as anaphylactic shock. That's why antiallergic drugs are called ANTIhistamines.

They block histamine receptors and thus stop the development of allergy symptoms.

Depending on the type of reaction, antihistamines are prescribed by injection (for severe forms) and orally (for milder ones). It is understandable: if we inject the drug with the help of an intramuscular or intravenous injection, it instantly enters the bloodstream and is included in the work. And if we drink this medicine, time must pass before the active substance is absorbed into the blood from the gastrointestinal tract.

All anti-allergy drugs can be divided into several groups:

1. Symptomatic drugs.

2. Medicines for the treatment of chronic allergic inflammation in the affected organ.

3. Medicines for local therapy.

Symptomatic drugs are intended to alleviate the course of allergic diseases. The leading place among them belongs to drugs called antihistamines.

These agents counteract the damaging effects of the main mediator of allergic reactions, histamine. Today, doctors are armed with three generations of antihistamines that differ in their characteristics.

The selection of antihistamines is carried out individually, taking into account the nature of food allergies, the age of the child and the nature of concomitant diseases. Symptomatic drugs also, for example, include bronchodilators. They are used for asthma attacks.

Antihistamines for the treatment of chronic allergic inflammation in the affected organ are divided into non-hormonal and hormonal. The latter drugs are more powerful and effective.

The appointment of drugs in this group is carried out depending on the clinical manifestations of food allergies, the severity of the disease, the age of the child. It must be remembered that these drugs are generally effective only with long-term regular use.

We must remember that drug therapy for food allergies is a long process, you need to patiently and persistently follow medical recommendations.

We must also remember that some treatments for food allergies are absolutely contraindicated and can harm the child. So, with food allergies, treatment with herbs and many traditional medicines is contraindicated, and psychotherapy and reflexology, except for bioresonance treatment, almost do not give a significant effect.

Treatment with herbs and preparations based on them increases the risk of developing an allergy to plant pollen in the future. The same "service" can be provided by biologically active additives, which often contain plant components.

Antihistamines are standard therapy for atopic dermatitis. They are used as an additional remedy for external treatment with severe itching and associated rashes.

Antihistamines are divided into three generations:

means of the 1st "old" generation;

means of the 2nd and 3rd generations ("new" generation).

Antihistamine drugs of the 1st "old" generation

Antihistamines of the 1st generation are more often used to treat acute reactions, in the treatment of itchy allergic dermatoses. Most of them are available in solutions in ampoules, but there are forms in tablets, syrups and powders.

Antihistamines of the 1st "old" generation (forms for oral administration)

Chloropyramine, Clemastine, Dimetindene, Quifenadine, Hifenadine, Mebhydrolin, Ketotifen.

Disadvantages of older generation antihistamines:

Incomplete connection with H1 receptors, as a result of which relatively high doses are required;

Short-term action - taking several times a day

Development of addiction - it is necessary to alternate drugs of different groups every 10-14 days

Sedative and hypnotic effect

Antihistamine drugs of the 2nd and 3rd "new" generations

Loratodin, cyterizine, fexofenadine, desloratadine.

Currently, in the treatment of atopic dermatitis, antihistamine drugs of the “new”, that is, the 2nd and 3rd generations, are widely used.

Antihistamine drugs of the 2nd and 3rd generations are used for basic and anti-relapse therapy.

Antihistamines of the "new" generation do not have sedative and hypnotic effects. They have a selective effect, causing blockade of only H1-histamine receptors. The duration of their action is up to 24 hours, so most of these drugs are prescribed once a day.

After taking most antihistamines, their residual effect may last for one week after withdrawal (this circumstance must be taken into account when conducting an allergy examination). A significant difference between the antihistamine drugs of the "new" generation is that they have not only H1-blocking action, but also anti-allergic and anti-inflammatory effects.

If long-term use is necessary, only antihistamines of the “new” generation are used.

The absence of undesirable side effects characteristic of the first antihistamines allows to significantly expand the list of indications for the appointment of modern H1-antagonists.

Benefits of 2nd generation antihistamines over 1st generation:

Rapid onset of action (from 30 minutes - acute cases);

The possibility of taking at any time of the day (including in the first half of the day) good absorption from the digestive tract the possibility of using in young children a long duration of the antihistamine effect (up to 24 hours), which allows you to take the drug once a day.

No blockade of other types of receptors

Lack of penetration through the blood-brain barrier at therapeutic doses

Lack of connection with food intake

Non-addictive, even with long-term use (3 to 6 months)

The almost complete absence of side effects associated with exposure to the nervous and cardiovascular systems.

The use of antihistamine drugs in the treatment of children with atopic dermatitis.

Children after a year, as a rule, are prescribed drugs of a new generation.

The "new" generation drugs that are approved for use in children from 6 months of age are antihistamine drugs based on cetirizine (generic active ingredient).

VACCINATION

Since allergy is an immune disorder, allergic rhinitis and bronchial asthma can be treated with vaccines from allergens to which the child is hypersensitive. Indications for vaccination are determined based on the results of skin tests with allergens.

The vaccine is administered under a special scheme subcutaneously or buried under the tongue. Such treatment is applicable only in children over 5 years of age and should be carried out by an allergist.

And finally, the most interesting question: do allergy medications cause allergies? Yes! We will not go into the technical details of the complex mechanisms that may lead to this development.

Let's just say that an allergy to antihistamines is extremely rare, but it happens. There is only one way out - to change the drug.

Antihistamines are a group of drugs that perform a competitive blockade of histamine receptors in the body, which leads to inhibition of the effects mediated by it.

Histamine is a neurotransmitter that can affect the respiratory tract (causing swelling of the nasal mucosa, bronchospasm), skin (itching, blistering hyperemic reaction), gastrointestinal tract (intestinal colic, stimulation of gastric secretion), cardiovascular system (expansion of capillary vessels, increased vascular permeability, hypotension, cardiac arrhythmias), smooth muscles.

Strengthening its influence cause allergic reactions, so antihistamines are used to combat the manifestations of allergies. Another area of ​​their application is symptomatic therapy / elimination of symptoms in colds.

Currently, there are three groups of drugs (according to the receptors they block):

H1 blockers - used in the treatment of allergic diseases.

H2-blockers - used in the treatment of diseases of the stomach (help reduce gastric secretion).

H3 blockers are used in the treatment of neurological diseases.

Among them, cetrin (cetirizine), phencarol (hifenadine), diphenhydramine, clemastine, suprastin stop the emission (for example, cromoglycic acid) or the action (like diphenhydramine) of histamines.

Available in the form of tablets, nasal spray, drops, including eye drops, solution in ampoules for intramuscular injection (usually for emergency therapy).

There are several generations of antihistamines. With each generation, the number and strength of side effects and the likelihood of addiction decrease, the duration of action increases.

First generation

Before buying a medicine - paracetamol, ibuprofen, antiallergic (antihistamine) drugs, cold and cold remedies, you need to know:

Paracetamol

Pain reliever, antipyretic, anti-inflammatory agent. The active substance is paraacetaminophen, on the basis of which many other similar drugs are produced in different countries, such as acetaminophen, panadol, efferalgan, myalgin, paramol, pilaren, etc.

Benefit. In its action, paracetamol is in many ways close to aspirin, but has less pronounced side effects. It does not reduce blood viscosity, so it is safe to use in preparation for and after surgery.

It is less likely than aspirin to cause allergic reactions and is less irritating to the stomach. Paracetamol is part of many combined preparations in combination with aspirin, analgin, caffeine, etc. It is available in the form of tablets, capsules, mixtures, syrup, "effervescent" powders (panadol, panadon).

Possible harm. When combined with alcohol, it can damage and even destroy the liver. Therefore, it, like aspirin, is dangerous for people who regularly drink alcohol. Paracetamol has a negative effect on the liver and in case of violation of the norm of its intake (in case of overdose).

Output. Take no more than 2 g per day (4 tablets of 500 mg) - People who drink alcohol daily should stop taking paracetamol.

Ibuprofen

It has an analgesic and anti-inflammatory effect. Ibuprofen is the active ingredient in drugs such as Brufen, Arthryl, Advil, Naproxen, etc. These drugs are chemically identical, but differ in the duration of the therapeutic effect.

Benefit. Help with fever, muscle and joint pain (rheumatoid arthritis, arthrosis, etc.)

Possible harm. If the body is severely dehydrated as a result of hard physical work, heat, or taking diuretics (diuretics), then ibuprofen can adversely affect the kidneys. The risk of kidney damage increases with regular use of ibuprofen.

Long-term use of ibuprofen is dangerous for the stomach. In people who constantly drink alcohol, taking ibuprofen can affect the liver.

Output. Try to avoid dehydration. When taking ibuprofen, it is necessary to monitor the work of the kidneys. In no case should you exceed the allowable daily intake (6 tablets of ibuprofen 200 mg or 2 tablets of naproxen 220 mg).

Antiallergic (antihistamine) drugs

The drugs in this group are intended for people suffering from pollinosis (hay fever), asthma, hives or other allergic diseases.

Benefit. They relieve runny nose, sneezing, sore throat, coughing and suffocation, unbearable itching and other symptoms of these diseases.

Possible harm. Most common drugs in this group, such as suprastin, tavegil, diphenhydramine, zaditen, peritol, etc., have a sedative effect, that is, they cause drowsiness, inhibition of reactions, and general weakness. Therefore, it is dangerous to take them to car drivers, pilots, operators, dispatchers, etc., that is, people who require constant attention and quick reaction in difficult situations.

Output. To avoid the risk, you should take a new generation of antihistamines that do not cause drowsiness and inhibition of reactions, such as claritin, kestin, which act for 12-24 hours. Sedative antihistamines are best taken in the afternoon and at night.

Remedies for the common cold

The action of drugs such as sanorin, naphthyzin, galazolin, otrivin, etc., is that they constrict blood vessels in the swollen mucous membrane of the nasal passages, as a result of which the nasal passages themselves expand.

Benefit. With a cold, the runny nose is weakened or stops, breathing through the nose is restored, and the headache disappears.

Possible harm. When taking these drugs, blood vessels are narrowed not only in the nose, as a result of which blood pressure may increase in patients with hypertension.

This is especially dangerous for hypertensive patients, since the drugs they take to lower blood pressure will be ineffective. In addition, drugs in this group are dangerous for those who take antidepressants such as pyrazidol, pirlindol, nialamide.

Output. For people suffering from hypertension, common cold remedies can only be taken under the control of blood pressure. In the event of an increase in pressure, the dosage of antihypertensive drugs should be increased.

Patients with depression who take the listed antidepressants or the like, drugs in this group are contraindicated.

Complex preparations for colds used with antihistamines

Among the complex anti-cold drugs, such as askofen, citramon, sedalgin, alkaseltzer plus, bicarmint, etc. are especially known.

Benefit. They help to get rid of various symptoms of the disease at the same time: cough, runny nose, pain, fever, allergic manifestations.

Possible harm. When taking complex drugs, the so-called "unforeseen overdose" is quite often allowed.

This happens when, with a severe cold or headache, in order to increase the effectiveness of treatment, a complex cold preparation containing aspirin is added to the intake of aspirin. As a result, peptic ulcer disease may worsen or even gastric bleeding occurs.

If, with an allergic rhinitis, in addition to suprastin, you also take a complex preparation containing an antihistamine, then everything together will act as a strong sleeping pill. Sometimes liver disorders are associated with a similar overdose of paracetamol or ibuprofen.

Output. Before taking a complex preparation for a cold, you should carefully read its composition indicated on the package or in the insert, and do not take separately those medicines that are included in it.

Antiallergic drugs for children: characteristics, principle of action, benefits and harms

Diazolin (mebhydrolin);

Peritol (cyproheptadine).

In principle, the effectiveness of the above drugs has been confirmed by many years of experience, but this same experience indicates a whole bunch of side effects:

All these drugs to a greater or lesser extent affect the central nervous system, providing sedative and hypnotic effects.

Classical antihistamines dry out the mucous membranes. Dry mouth, sputum viscosity in the lungs (which is especially dangerous in acute respiratory viral infections, as it seriously increases the risk of developing pneumonia) - does not affect the child's condition in the best way.

The simultaneous use of first-generation antiallergic drugs with other drugs enhances the effect of the use of the latter. Thus, antipyretic, analgesic, hypnotic effects are enhanced. Especially dangerous is the combination of antihistamines with other drugs that actively affect the functioning of the central nervous system. In this case, the development of side effects up to fainting is possible. The combination with alcoholic beverages is highly undesirable.

The action of such drugs, although effective, is limited to 2-3 hours (some last up to 6 hours).

Of course, it does not come without advantages. Firstly, first-generation antihistamines are relatively affordable, and secondly, they are great for short-term treatment of allergies. That is, if, for example, a child ate an excessive amount of chocolate and a short-term intake of an antihistamine is required, you can safely use the same Tavegil or Fenkarol.

Most first-generation allergy remedies are forbidden to be taken orally by nursing mothers; only their local forms can be used - ointment, cream, spray. The exception is Suprastin and Fenkarol (from three months of pregnancy). Each drug has its own characteristic feature, which is important to consider when drawing up a treatment regimen. So, it is not advisable for a baby prone to constipation to use Tavegil; a child suffering from gastrointestinal diseases is prohibited from taking Suprastin; and children with impaired liver function need to be careful with the use of Phencarol.

For babies under one year old, taking first-generation antiallergic drugs is undesirable. For the smallest, there are more modern drugs that are practically safe and very effective.

The principles of action of antihistamines, the second generation on the children's body

The undoubted advantage of antiallergic drugs of the second and third generation is the absence or minimization of the sedative, hypnotic, CNS inhibitory effect.

In addition, they have a number of other advantages: they do not penetrate the fetoplacental barrier (that is, such drugs can be used during pregnancy);

do not dry mucous membranes;

do not affect the mental and physical activity of the child;

have a quick and long-lasting (up to 24 hours) therapeutic effect - one tablet is enough to forget about allergy symptoms for the whole day;

in addition to antiallergic, they have antiemetic, antiulcer and other actions (some drugs); do not reduce their effectiveness with long-term use.

Perhaps the only drawback of second-generation antiallergic drugs is their ability to have a negative impact on the children's cardiovascular system. Due to the possible cardiotoxic effect, the use of such drugs is not recommended for children with various pathologies of the heart and blood vessels.

Among the most prominent representatives of the second generation:

Claritin (loratidin);

Allergy treatment, antihistamines

Diazolin dragee 50mg №20

Diazolin tab. 100mg #10

Suprastin (chloropyramine) is one of the most widely used sedative antihistamines. It has significant antihistamine activity, peripheral anticholinergic and moderate antispasmodic action.

Effective in most cases for the treatment of seasonal and year-round allergic rhinoconjunctivitis, angioedema, urticaria, atopic dermatitis, eczema, itching of various etiologies; in parenteral form - for the treatment of acute allergic conditions requiring emergency care. It does not accumulate in the blood serum, so it does not cause an overdose with prolonged use. The effect comes on quickly, but is short-lived; to increase its duration, it is combined with non-sedating H1-blockers.

Suprastin injection 2% 1ml amp. No. 5 (Egis, Hungary)

Suprastin tab. 25mg №20 (Egis, Hungary)

Chloropyramine g / x tab. 25mg #40

Tavegil (clemastine) is a highly effective antihistamine drug similar in action to diphenhydramine. It has a high anticholinergic activity, but penetrates the blood-brain barrier to a lesser extent.

In an injectable form, which can be used as an additional remedy for anaphylactic shock and angioedema, for the prevention and treatment of allergic and pseudo-allergic reactions. However, there is an allergy to tavegil.

Peritol (cyproheptadine), along with antihistamine, has a significant antiserotonin effect. It is often used in some forms of migraine to increase appetite.

Peritol syrup 2mg/5ml 100ml (Egis, Hungary)

Peritol tab. 4mg №20 (Egis, Hungary)

Pipolfen (promethazine) - a pronounced effect on the central nervous system, is used as an antiemetic and to potentiate anesthesia.

Pipolphen other 25mg №20 (Egis, Hungary)

Pipolfen solution for injections 50mg 2ml amp. №10 (Egis, Hungary)

Diprazine tab. 25mg #20

Phencarol (quifenadine) - has less antihistamine activity than diphenhydramine, but is also characterized by less penetration through the blood-brain barrier, which determines the lower severity of its sedative properties. In addition, fenkarol not only blocks histamine H1 receptors, but also reduces the content of histamine in tissues. Can be used in the development of addiction to other sedative antihistamines.

Fenkarol tab. 25mg №20 (Latvia)

Second generation antihistamines (non-sedating).

Unlike the first generation, they have almost no sedative and anticholinergic effects, do not penetrate the blood-brain barrier, do not reduce mental and physical activity, are not adsorbed with food in the gastrointestinal tract, have a high affinity for H1 receptors, and have a rapid therapeutic effect. . However, for them, a cardiotoxic effect was noted to varying degrees; when they are taken, constant monitoring of cardiac activity is required (appointed on an outpatient basis). They should not be taken by patients with disorders of the cardiovascular system, elderly patients.

The effect comes on quickly and for a longer time (delayed elimination).

When using drugs in therapeutic doses, a minimal sedative effect is observed. Some particularly sensitive individuals may experience moderate drowsiness, which does not require discontinuation of the drug.

The absence of tachyphylaxis (decrease in antihistamine activity) with prolonged use.

The cardiotoxic effect occurs due to the ability to block the potassium channels of the heart muscle, the risk of a cardiotoxic effect increases when antihistamines are combined with antifungals (ketoconazole and itraconazole), macrolides (erythromycin and clarithromycin), antidepressants (fluoxetine, sertraline and paroxetine), when drinking grapefruit juice and in patients with severe hepatic impairment.

There are no parenteral forms, only enteral and local dosage forms.

The most common second-generation antihistamines are:

Trexil (terfenadine) is the first second-generation antihistamine drug that does not have an inhibitory effect on the central nervous system, but with a significant cardiotoxic effect and an increased ability to cause fatal arrhythmias.

Trexil tab. 60mg №100 (Ranbaxi, India)

Gistalong (astemizole) is one of the longest acting drugs of the group (up to 20 days). It is characterized by irreversible binding to H1 receptors. Virtually no sedative effect, does not interact with alcohol.

Effective in chronic allergic diseases, with an acute process, its use is impractical. But the risk of developing serious heart rhythm disturbances, sometimes fatal, increases. Due to these dangerous side effects, the sale of astemizole in the United States and some other countries has been suspended.

Astemizole tab. 10mg #10

Histalong tab. 10mg №20 (India)

Semprex (acrivastine) is a drug with high antihistamine activity with a minimally pronounced sedative and anticholinergic effect. The therapeutic effect is achieved quickly, but for a short time.

Semprex caps. 8mg №24 (GlaxoWellcome, UK)

Fenistil (dimetendene) is closest to first-generation antihistamines, but differs from them in a significantly lesser sedative effect, higher antiallergic activity and duration of action than first-generation drugs. There is a gel for external use.

Claritin (loratadine) is one of the best-selling second-generation drugs. Its antihistamine activity is higher than that of astemizole and terfenadine, due to the greater strength of binding to peripheral H1 receptors.

There is no sedative effect, it does not potentiate the effect of alcohol. It practically does not interact with other drugs and does not have a cardiotoxic effect. It can be taken by drivers, children from 1 year old.

Claritin syrup 5mg/5ml 120ml (Schering-Plough, USA)

Claritin tab. 10mg №10 (Schering-Plough, USA)

Loratadine tab. 10mg #10

Agistam tab. 10mg #12

Third generation antihistamines (metabolites).

They are active metabolites of second-generation antihistamines. They do not have a sedative and cardiotoxic effect. In this regard, the drugs are approved for use by persons whose activities require increased attention.

Zyrtec, cetrin (cetirizine) is a highly selective blocker of peripheral H1 receptors. Cetirizine is almost not metabolized in the body, the rate of its excretion depends on the function of the kidneys. It penetrates well into the skin, and is effective in skin manifestations of allergies.

The effect appears 2 hours after ingestion and lasts 24 hours. Do not have a sedative and cardiotoxic effect in therapeutic doses. Be wary appoint in violation of kidney function.

Cetrin tab. 10mg No. 20 (Dr. Reddy's Laboratories, India)

Telfast (fexofenadine) is a metabolite of terfenadine. Does not metabolize in the body, does not interact with drugs, does not have a sedative effect and does not affect psychomotor activity. An effective and safest drug among antihistamines.

Telfast tab. 120mg №10 (Hoechst Marion Roussel)

Telfast tab. 180mg №10 (Hoechst Marion Roussel)

Dear friends, I greet you!

Acrivastine (Semprex) and terfenadine also belonged here, but they caused severe cardiac arrhythmias, even death, so they disappeared from the shelves.

pros:

1. High selectivity for H1 receptors.
2. They do not have a sedative effect.
3. They operate for a long time.
4. Side effects when taking them are noted much less frequently.
5. They are not addictive, so they can be used for a long time.

Minuses:

Safe at recommended dosages. Passing through the liver, they are metabolized by it. But if the functions are impaired, non-metabolized forms of the active substance accumulate in the blood, which can cause heart rhythm disturbances. You have probably seen that some of the annotations mention the QT interval. This is a special section of the electrocardiogram, the lengthening of which indicates the likelihood of ventricular fibrillation and sudden death.

In this regard, patients with impaired liver and kidney function need to change the dose.

3rd generation antihistamines

This group of drugs includes desloratadine ( Erius, Lordestin, Desal, etc.), levocetirizine ( Xizal, Suprastinex and others), fexofenadine ( Allegra, Feksadin, Fexofast, etc.).

These are active metabolites of second generation drugs, so their metabolic products do not accumulate in the blood, causing heart problems, and do not interact with other drugs, causing side effects.

Pros:

• Outperforms their predecessors in performance.
• They act quickly and for a long time.
• They do not have a sedative effect.
• Do not slow down the reaction rate.
• Do not enhance the effect of alcohol.
• They are not addictive, so they can be used for a long time.
• They do not have a toxic effect on the heart muscle.
• There is no need to change the dose in patients with impaired liver and kidney function.
• The safest.

I didn't find any cons in general.

Well. The preparatory work is done, you can move on to the preparations.

First of all, let's sketch out what might be of interest to an allergy sufferer who asks you for an antiallergic drug.

He wants the drug:

• Was efficient.
• Started to act quickly.
• Taken once a day.
• Didn't cause drowsiness.
• Did not reduce the reaction rate (for motor transport drivers).
• Was compatible with alcohol.

And you and I, as always, are still interested in nursing, children and the elderly.

This is how we will analyze the active substances using the example of the most popular over-the-counter drugs.

1 generation.

Suprastin pills

• Begins to act in 15-30 minutes, the action lasts 3-6 hours.
• shown with any allergic reactions, except for bronchial asthma. In general, antihistamines are not the main drugs for asthma. They are weak for asthmatics. If they are used, then only in combination with bronchodilators. And the first generation does cause dryness of the mucous membranes, making it difficult to expectorate.
• Causes drowsiness.
• Pregnant, lactating is contraindicated.
• Children - from 3 years (for this form).
• A lot of side effects.
• It is better not to recommend for the elderly.
• Drivers can't.
• The effect of alcohol enhances.

Tavegilpills

Everything is the same as suprastin, only it lasts longer (10-12 hours), so it is taken less often.

Other differences:

• The sedative effect is less compared to Suprastin, but the therapeutic effect is also weaker.
• Children - from 6 years old (for this form).

Diazolintablets, dragees

• It begins to act in 15-30 minutes, the action can last for an incomprehensible amount. They write that even up to 2 days. Then the question is the frequency of reception.
• Children from 3 years old. Up to 12 years - a single dose of 50 mg, then - 100 mg.
• May cause irritability in children.
• Pregnant, lactating women are not allowed.
• Not recommended for the elderly.
• Drivers can't.

Fenkarolpills

• It penetrates poorly through the BBB, so the sedative effect is negligible.
• Starts working in an hour.
• From 3 to 12 years old - 10 mg tablets, from 12 years old - 25 mg, from 18 years old - 50 mg.
• In pregnancy - weigh the risk / benefit, contraindicated in the 1st trimester.
• Nursing is not allowed.
• Side effects are much less than those discussed above.
• Drivers of vehicles beware.

2 generation

Claritin (loratadine) tablets, syrup

• Begins to act 30 minutes after ingestion.
• The action lasts 24 hours.
• Does not cause drowsiness.
• Does not cause arrhythmias.
• Indications: hay fever, urticaria, allergic dermatitis.
• Lactation is not allowed.
• Pregnancy - with caution.
• Children - syrup from 2 years old, tablets from 3 years old.
• Does not enhance the effect of alcohol.
• Drivers can.

I noticed that the instructions for generics indicate that it is contraindicated during pregnancy. Why, then, is there a “loophole” for Claritin in the form of a vague “with caution”?

Zyrtec (cetirizine ) - tablets, drops for oral administration

• Begins to act within an hour, the effect lasts 24 hours.
• Does not have a sedative effect (in therapeutic doses).
• Indications: urticaria, dermatitis, Quincke's edema.
• Effective for cold allergies.
• The greatest effect was shown in the treatment skin allergies.
• Children - drops from 6 months, tablets - from 6 years.
• Refrain from alcohol.
• Drivers, be careful.

Kestin (ebastine)- coated tablets 10 mg, 20 mg and lyophilized 20 mg

• The effect of the film-coated tablets begins after 1 hour and lasts 48 hours ( record holder!).
• After 5 days of admission, the effect persists for 72 hours.
• Indications: hay fever, urticaria, other allergic reactions.
• Pregnancy, lactation - contraindicated.
• Children: from 12 years old.
• Drivers can.
• Hearts - with caution.
• 20 mg film-coated tablets - recommend if lower dosage fails.
• 20 mg lyophilized tablets dissolve instantly in the mouth: for those who find it difficult to swallow.

Fenistil (dimetindene) drops, gel

• Drops - the maximum concentration in the blood after 2 hours.
• Indications: hay fever, allergic dermatoses.
• Drops for children - from 1 month. Caution up to 1 year to avoid apnea (stop breathing) against the background of a sedative effect.
• Pregnancy - except for the 1st trimester.
• Nursing is not allowed.
• Contraindicated - bronchial asthma, prostate adenoma, glaucoma.
• The effect of alcohol enhances.
• Drivers better not.
• Gel - for skin dermatosis, insect bites.
• Emulsion - easy to take on the road, ideal for a bite: thanks to the roll-on applicator, it can be applied pointwise.

3rd generation

Aerius (desloratadine) - tablets, syrup

• Begins to act in 30 minutes and lasts 24 hours.
• Indications: hay fever, urticaria.
• Especially effective in allergic rhinitis - eliminates nasal congestion. It has not only anti-allergic, but also anti-inflammatory effect.
• Pregnancy and lactation - contraindicated.
• Children - tablets from 12 years old, syrup from 6 months.
• Side effects are very rare.
• Drivers can.
• The effect of alcohol does not enhance.

Allegra (fexofenadine) - tab. 120, 180 mg

• Begins to act in an hour, and the action lasts 24 hours.
• Indications: allergic (tablet 120 mg), urticaria (tablet 180 mg).
• Pregnancy and lactation - contraindicated.
• Children - from 12 years old.
• Drivers, be careful.
• Seniors, be careful.
• The effect of alcohol - no indication.

Nasal and ophthalmic antihistamines

Allergodil- nasal spray.

It is used for allergic rhinitis in children from 6 years old and adults 2 times a day.

Suitable for long term use.

Allergodil eye drops - children from 4 years old and adults 2 times a day for allergic.

Sanorin-analergin

It is used from the age of 16 for allergic rhinitis. It is good because it contains vasoconstrictor and antihistamine components, i.e. acts both on the cause of allergic rhinitis and on the symptom (congestion). Begins to act in 10 minutes, and the action lasts 2-6 hours.

Pregnant and lactating is contraindicated.

Vizin Alergi- eye drops.

Contains only an antihistamine component. It is applied from 12 years, not on lenses. Not recommended for pregnant and lactating women.

That's all.

Finally, I have questions for you:

1. What other popular antihistamines have I not mentioned here? Their features, chips?
2. What questions should you ask a customer asking for an allergy remedy?
3. Have something to add? Write.

With love to you, Marina Kuznetsova

To suppress the development of an allergic reaction, it is necessary to take an antihistamine. Currently, there are a huge number of medicines from this group. All of them are divided by generations. The list of new generation antihistamines is quite wide and allows you to choose the best medicine for treatment. In the article we will take a closer look at the most effective medicines in this category.

General concept

Most people have heard of antihistamines, but not everyone knows what they are and how they work. This is the name of a group of drugs that can act on histamine receptors, a mediator of allergic reactions. Upon contact with an irritant, the human body begins to produce specific substances, among which histamine is the most active. When this substance “meets” with certain receptors, symptoms such as tearing, reddening of the skin, itching, and a rash develop.

Antiallergic drugs are able to block these receptors and, as a result, resist the appearance of unpleasant symptoms. Without them, negative processes in the body will continue.

Currently, there is a significant increase in the number of people suffering from this or that type of allergy. An inadequate reaction of the immune system can develop against the background of disorders of the endocrine or nervous system, but most often the cause is external irritants: plant pollen, wool, dust, chemicals, some foods.

Treatment with antihistamines

In most cases, allergies cannot be completely cured. Medicines that affect histamine receptors will help get rid of unpleasant symptoms or prevent their occurrence.

To date, there are several generations of these medicines. And if the first antiallergic drugs brought not only long-awaited relief, but also many side effects, then the new generation antihistamines, the list of which we will consider below, are practically devoid of drawbacks and have practically no contraindications for use.

Medicines of this category are prescribed in the following cases:

• with year-round or seasonal rhinitis;
• with a negative reaction to flowering plants;
• when symptoms of food and drug allergies occur;
• with atopic dermatitis;
• with urticaria and itching of the skin;
• with bronchial asthma;
• with angioedema;
• with allergic conjunctivitis.

New generation antihistamines: an overview

Among all antiallergic medicines, the latest generation of drugs are considered the safest. They belong to prodrugs, which means that when they enter the body, the substances contained in the composition are converted into active metabolites. Such agents act only on histamine H-1 receptors and do not adversely affect the central nervous system.

The list of new generation antihistamines is small, however, compared with the precursor drugs, they can be prescribed to almost all patients suffering from various types of allergic reactions. Such funds allow you to quickly stop the already manifested symptoms and do not have a toxic effect on the heart. The following drugs are popular:

• "Cetirizine".
• "Fexofenadine".
• "Erius".
• "Fexofast".
• "Ksizal".
• "Levocetirizine".
• "Desal".
• "Caesera".
• "Desloratadine".
• "Kestin".

Features of drugs

The most common antiallergic drugs of the latest generation are those that contain fexofenadine in their composition. The substance belongs to selective inhibitors of H-1 histamine receptors and is able to stabilize mast cell membranes. The component inhibits the process of migration of leukocytes to the focus of the inflammatory process.

4th generation antihistamines based on cetirizine are considered one of the most effective. They are able to quickly stop the development of skin allergic reactions. They have a pronounced antipruritic and antiexudative effect.

Each of the modern anti-allergy drugs is prescribed only after the examination. The dosage regimen and duration of use is determined strictly individually.

"Erius": a description of the medication

An antihistamine based on desloratadine is produced by a branch of the pharmaceutical company Schering-Plough Corporation / USA in Belgium. You can buy medicines in tablet form and in the form of syrup. In addition to the main active ingredient, the tablets contain titanium dioxide, talc, calcium hydrogen phosphate dihydrate, lactose monohydrate, white wax, corn starch, microcrystalline cellulose.

The syrup contains such auxiliary components as citric acid, sorbitol, sodium benzoate, propylene glycol, sodium citrate dihydrate, sucrose. Tablets are packaged in packs of 7 and 10 pieces per blister. The syrup has the appearance of a yellow liquid and is available in 60 and 120 ml bottles.

Indications for appointment

Tablets "Erius" instructions for use recommend taking with seasonal rhinitis, lacrimation, itching of the nasal mucosa, seasonal pollinosis, chronic idiopathic urticaria. As prescribed by a specialist, the medication can also be used for other allergic conditions. For example, many patients say that "Erius" copes well with signs of neurodermatitis, food allergies, atopic dermatitis.

As part of complex therapy, an antihistamine can be taken for chicken pox, pink lichen, scabies and pseudo-scabies. "Erius" will effectively eliminate severe itching and help you fall asleep.

In pediatric practice, an antiallergic drug is used in the form of a syrup. The manufacturer claims that it can be given to babies older than 1 year. The dosage will depend on the age category. Erius tablets are suitable for adult patients and children from 12 years of age. Instructions for use recommends taking 1 tablet (5 mg) per day.

"Cetirizine": reviews

Modern antiallergic drugs are able to stop the development of the disease at the earliest stages. This is extremely important in severe allergic reactions. That is why many experts in the list of new generation antihistamines in the first place is "Cetirizine". An agent based on the active ingredient of the same name quickly relieves bronchospasm, attacks of bronchial asthma, and prevents the development of Quincke's edema. In addition, the medication will be effective for hives, pollinosis, hay fever, eczema, allergic dermatitis.

The antihistamine drug "Cetirizine" is available in the form of drops for oral administration, syrup and tablets. 1 ml of liquid solution contains 10 mg of cetirizine. One tablet contains the same amount of active substance. A noticeable effect from the use of a histamine H-1 receptor blocker can be seen an hour after administration. The duration of action is 24 hours. In bronchial asthma, it is used in combination with the bronchodilator drug Fenspiride.

Contraindications and side effects

Treatment with "Cetirizine" should be abandoned in case of hypersensitivity to the main component and hydroxyzine. It is forbidden to prescribe an antihistamine to people who are on hemodialysis or have kidney failure, during breastfeeding and pregnancy. Contraindications are also conditions associated with lactase deficiency, glucose-galactose malabsorption and lactose intolerance. With caution take "Cetirizine" simultaneously with barbiturates, ethanol-containing drugs and opioid analgesics.

Excellent tolerance is a huge advantage of the drug. Side effects while taking tablets, drops or syrup are extremely rare. This is mainly due to an overdose of the active substance. In such cases, the following symptoms may develop:

• dizziness;
• migraine;
• nervous excitement;
• tachycardia;
• insomnia;
• urinary retention;
• myalgia;
• skin rashes, eczema.

What is Kestin?

Another effective histamine receptor blocker is Kestin. It is produced by the pharmaceutical company Nycomed Danmark ApS (Denmark). Modern antiallergic agent is quite expensive. The average price of tablets (10 pieces per pack) is 380-400 rubles.

What is the composition of this medicine? Ebastine is the main component that blocks histamine H-1 receptors. The substance quickly eliminates spasms of the smooth muscles of the bronchi, reduces exudation, stops the manifestation of skin allergic reactions. "Kestin" is available in the form of tablets, which may contain various amounts of ebastine (10 or 20 mg) and syrup. The manufacturer also offers lozenges containing 20 mg of the active substance.

Who suits?

Any 4th generation antihistamines, including Kestin, can be taken only after consultation with an allergist. Most often, the drug is prescribed to adult patients. The instruction allows the use of tablets in pediatric practice, but only if the child is over 12 years old. Lozenges are prescribed only from the age of 15. The syrup can be used to treat children from 6 years of age.

"Kestin" effectively eliminates the symptoms of year-round and seasonal rhinitis of various origins, conjunctivitis, urticaria, Quincke's edema. The drug relieves symptoms caused by drug, food, insect allergies.

It is worth refraining from using "Kestin" during pregnancy, lactation, with intolerance to ebastine or other components of the drug. Lozenges are not prescribed for patients suffering from phenylketonuria. Under the supervision of a physician, an antihistamine is used for ischemic disease, hypokalemia, renal and hepatic insufficiency.

Description of the drug "Ksizal"

If necessary, symptomatic treatment of allergic skin reactions, urticaria, rhinorrhea, Quincke's edema, hay fever, many prefer the modern remedy "Ksizal". The cost of one package is 420-460 rubles. The drug is produced at pharmaceutical factories in Belgium, Switzerland and Italy.

The main active component of Xyzal is levocetirizine. The substance has pronounced anti-allergic properties. The active metabolite is able to prevent the development of allergies or significantly alleviate the course of the pathological condition. The substance reduces the permeability of the vascular walls, blocks the activity of cytokines and inflammatory mediators, and inhibits the movement of eosinophils. The clinical effect of the drug persists for 24 hours.

When are they assigned?

In the list of new allergy drugs, Xyzal occupies the first position due to its quick effect and safety. A modern drug has practically no contraindications to the appointment and rarely provokes the development of side effects. It is recommended to use it for a variety of allergic reactions: Quincke's edema, pollinosis, allergic dermatitis, itching, sneezing, nasal congestion against the background of seasonal or year-round rhinitis.

In the form of drops, "Ksizal" can be prescribed to babies from 2 years old. The tablets are suitable for use in children from 6 years of age and adults. The drug received many positive recommendations related to ease of use. One tablet of "Ksizal" can relieve allergy symptoms for a whole day.

"Levocetirizine" for allergies

The drug "Levocetirizine" is a cheaper analogue of "Ksizal". The cost of one package (10 tablets) ranges from 230-250 rubles. Also, the medicine can be purchased in the form of syrup and drops.

The active substance of the drug is able to block the endings of H-1 histamine receptors, thereby preventing the development of an inadequate response of the immune system. Allergy tablets "Levocetirizine" will be effective for hay fever, allergic dermatitis, seasonal and chronic rhinitis, lacrimation, sneezing, angioedema, urticaria.

The drug is not used to treat children under 6 years of age, during pregnancy and breastfeeding, with increased sensitivity to the components in the composition and severe renal failure.

The drug "Bamipin"

The list of new generation antihistamines includes agents intended for systemic use. However, in some cases, local medication is also required. To cope with skin manifestations of allergies, you should use special gels. One of these external medicines is Bamipin. It can be used already with the appearance of the first symptoms of urticaria, an allergic reaction to insect bites, itching of the skin, thermal burns. The drug is also available in the form of tablets.

Historically, the term "antihistamines" means drugs that block H1-histamine receptors, and drugs that act on H2-histamine receptors (cimetidine, ranitidine, famotidine, etc.) are called H2-histamine blockers. The former are used to treat allergic diseases, the latter are used as antisecretory agents.

Histamine, this most important mediator of various physiological and pathological processes in the body, was chemically synthesized in 1907. Subsequently, it was isolated from animal and human tissues (Windaus A., Vogt W.). Even later, its functions were determined: gastric secretion, neurotransmitter function in the central nervous system, allergic reactions, inflammation, etc. Almost 20 years later, in 1936, the first substances with antihistamine activity were created (Bovet D., Staub A.). And already in the 60s, the heterogeneity of histamine receptors in the body was proven and three of their subtypes were identified: H1, H2 and H3, differing in structure, localization and physiological effects that occur during their activation and blockade. Since that time, an active period of synthesis and clinical testing of various antihistamines begins.

Numerous studies have shown that histamine, acting on the receptors of the respiratory system, eyes and skin, causes characteristic allergy symptoms, and antihistamines that selectively block H1-type receptors can prevent and stop them.

Most of the antihistamines used have a number of specific pharmacological properties that characterize them as a separate group. These include the following effects: antipruritic, decongestant, antispastic, anticholinergic, antiserotonin, sedative and local anesthetic, as well as the prevention of histamine-induced bronchospasm. Some of them are not due to histamine blockade, but to structural features.

Antihistamines block the action of histamine on H1 receptors by the mechanism of competitive inhibition, and their affinity for these receptors is much lower than that of histamine. Therefore, these drugs are not able to displace histamine bound to the receptor, they only block unoccupied or released receptors. Accordingly, H1 blockers are most effective in preventing immediate allergic reactions, and in the case of a developed reaction, they prevent the release of new portions of histamine.

According to their chemical structure, most of them are fat-soluble amines, which have a similar structure. The core (R1) is represented by an aromatic and/or heterocyclic group and is linked via a nitrogen, oxygen or carbon (X) molecule to the amino group. The core determines the severity of antihistamine activity and some of the properties of the substance. Knowing its composition, one can predict the strength of the drug and its effects, such as the ability to penetrate the blood-brain barrier.

There are several classifications of antihistamines, although none of them is generally accepted. According to one of the most popular classifications, antihistamines are divided into first and second generation drugs according to the time of creation. First-generation drugs are also called sedatives (according to the dominant side effect), in contrast to second-generation non-sedative drugs. At present, it is customary to isolate the third generation: it includes fundamentally new drugs - active metabolites that, in addition to the highest antihistamine activity, exhibit the absence of a sedative effect and the cardiotoxic effect characteristic of second-generation drugs (see table).

In addition, according to the chemical structure (depending on the X-bond), antihistamines are divided into several groups (ethanolamines, ethylenediamines, alkylamines, derivatives of alphacarboline, quinuclidine, phenothiazine, piperazine and piperidine).

First generation antihistamines (sedatives). All of them are well soluble in fats and, in addition to H1-histamine, also block cholinergic, muscarinic and serotonin receptors. Being competitive blockers, they reversibly bind to H1 receptors, which leads to the use of rather high doses. The following pharmacological properties are most characteristic of them.

• The sedative effect is determined by the fact that most of the first generation antihistamines, easily soluble in lipids, penetrate well through the blood-brain barrier and bind to the H1 receptors of the brain. Perhaps their sedative effect consists of blocking the central serotonin and acetylcholine receptors. The degree of manifestation of the sedative effect of the first generation varies in different drugs and in different patients from moderate to severe and increases when combined with alcohol and psychotropic drugs. Some of them are used as sleeping pills (doxylamine). Rarely, instead of sedation, psychomotor agitation occurs (more often in medium therapeutic doses in children and in high toxic doses in adults). Due to the sedative effect, most drugs should not be used during tasks that require attention. All first-generation drugs potentiate the action of sedative and hypnotic drugs, narcotic and non-narcotic analgesics, monoamine oxidase inhibitors and alcohol.
• The anxiolytic effect characteristic of hydroxyzine may be due to the suppression of activity in certain areas of the subcortical region of the central nervous system.
• Atropine-like reactions associated with the anticholinergic properties of drugs are most characteristic of ethanolamines and ethylenediamines. Manifested by dry mouth and nasopharynx, urinary retention, constipation, tachycardia and visual impairment. These properties ensure the effectiveness of the discussed remedies in non-allergic rhinitis. At the same time, they can increase obstruction in bronchial asthma (due to an increase in sputum viscosity), exacerbate glaucoma and lead to infravesical obstruction in prostate adenoma, etc.
• The antiemetic and antiswaying effects are also probably associated with the central anticholinergic effect of the drugs. Some antihistamines (diphenhydramine, promethazine, cyclizine, meclizine) reduce the stimulation of vestibular receptors and inhibit the function of the labyrinth, and therefore can be used for motion sickness.
• A number of H1-histamine blockers reduce the symptoms of parkinsonism, which is due to central inhibition of the effects of acetylcholine.
• Antitussive action is most characteristic of diphenhydramine, it is realized through a direct action on the cough center in the medulla oblongata.
• The antiserotonin effect, which is primarily characteristic of cyproheptadine, determines its use in migraine.
• The alpha1-blocking effect with peripheral vasodilation, especially seen with phenothiazine antihistamines, can lead to a transient decrease in blood pressure in sensitive individuals.
• Local anesthetic (cocaine-like) action is characteristic of most antihistamines (occurs due to a decrease in membrane permeability to sodium ions). Diphenhydramine and promethazine are stronger local anesthetics than novocaine. However, they have systemic quinidine-like effects, manifested by prolongation of the refractory phase and the development of ventricular tachycardia.
• Tachyphylaxis: decrease in antihistamine activity with long-term use, confirming the need for alternating drugs every 2-3 weeks.
• It should be noted that the first generation antihistamines differ from the second generation in the short duration of exposure with a relatively rapid onset of the clinical effect. Many of them are available in parenteral forms. All of the above, as well as low cost, determine the widespread use of antihistamines today.

Moreover, many of the qualities that were discussed allowed the “old” antihistamines to occupy their niche in the treatment of certain pathologies (migraine, sleep disorders, extrapyramidal disorders, anxiety, motion sickness, etc.) that are not associated with allergies. Many first-generation antihistamines are included in combination preparations used for colds, as sedatives, hypnotics, and other components.

The most commonly used are chloropyramine, diphenhydramine, clemastine, cyproheptadine, promethazine, phencarol, and hydroxyzine.

Chloropyramine(Suprastin) is one of the most widely used sedative antihistamines. It has significant antihistamine activity, peripheral anticholinergic and moderate antispasmodic action. Effective in most cases for the treatment of seasonal and year-round allergic rhinoconjunctivitis, angioedema, urticaria, atopic dermatitis, eczema, itching of various etiologies; in parenteral form - for the treatment of acute allergic conditions requiring emergency care. Provides a wide range of usable therapeutic doses. It does not accumulate in the blood serum, so it does not cause an overdose with prolonged use. Suprastin is characterized by a rapid onset of effect and short duration (including side effects). At the same time, chloropyramine can be combined with non-sedating H1-blockers in order to increase the duration of the antiallergic effect. Suprastin is currently one of the best-selling antihistamines in Russia. This is objectively related to the proven high efficiency, controllability of its clinical effect, the availability of various dosage forms, including injections, and low cost.

Diphenhydramine(Diphenhydramine) is one of the first synthesized H1-blockers. It has a fairly high antihistamine activity and reduces the severity of allergic and pseudo-allergic reactions. Due to the significant anticholinergic effect, it has an antitussive, antiemetic effect and at the same time causes dry mucous membranes, urinary retention. Due to lipophilicity, Diphenhydramine gives pronounced sedation and can be used as a hypnotic. It has a significant local anesthetic effect, as a result of which it is sometimes used as an alternative for intolerance to novocaine and lidocaine. Diphenhydramine is presented in various dosage forms, including for parenteral use, which determined its widespread use in emergency therapy. However, a significant range of side effects, unpredictability of consequences and effects on the central nervous system require increased attention in its application and, if possible, the use of alternative means.

clemastine(Tavegil) is a highly effective antihistamine drug similar in action to diphenhydramine. It has a high anticholinergic activity, but to a lesser extent penetrates the blood-brain barrier, which is the reason for the low frequency of observation of the sedative effect - up to 10%. It also exists in an injectable form, which can be used as an additional remedy for anaphylactic shock and angioedema, for the prevention and treatment of allergic and pseudo-allergic reactions. However, hypersensitivity to clemastine and other antihistamines with a similar chemical structure is known.

Dimethenden(Fenistil) - is closest to the second generation antihistamines, differs from the first generation drugs in a significantly lower severity of the sedative and muscarinic effect, high antiallergic activity and duration of action.

Thus, first-generation antihistamines that affect both H1- and other receptors (serotonin, central and peripheral cholinergic receptors, alpha-adrenergic receptors) have different effects, which determined their use in a variety of conditions. But the severity of side effects does not allow us to consider them as drugs of first choice in the treatment of allergic diseases. The experience gained with their use has allowed the development of unidirectional drugs - the second generation of antihistamines.

Second generation antihistamines (non-sedating). Unlike the previous generation, they have almost no sedative and anticholinergic effects, but differ in their selective action on H1 receptors. However, for them, a cardiotoxic effect was noted to varying degrees.

The following properties are the most common for them.

• High specificity and high affinity for H1 receptors with no effect on choline and serotonin receptors.
• Rapid onset of clinical effect and duration of action. Prolongation can be achieved due to high protein binding, accumulation of the drug and its metabolites in the body, and delayed elimination.
• Minimal sedative effect when using drugs in therapeutic doses. It is explained by the weak passage of the blood-brain barrier due to the peculiarities of the structure of these funds. Some particularly sensitive individuals may experience moderate drowsiness.
• Absence of tachyphylaxis with prolonged use.
• The ability to block the potassium channels of the heart muscle, which is associated with prolongation of the QT interval and cardiac arrhythmia. The risk of this side effect increases when antihistamines are combined with antifungals (ketoconazole and itraconazole), macrolides (erythromycin and clarithromycin), antidepressants (fluoxetine, sertraline and paroxetine), grapefruit juice, and in patients with severe liver dysfunction.
• Absence of parenteral formulations, however, some of them (azelastine, levocabastine, bamipine) are available as topical formulations.

Below are second-generation antihistamines with their most characteristic properties.

Loratadine(Claritin) is one of the most purchased drugs of the second generation, which is quite understandable and logical. Its antihistamine activity is higher than that of astemizole and terfenadine, due to the greater strength of binding to peripheral H1 receptors. The drug is devoid of a sedative effect and does not potentiate the effect of alcohol. In addition, loratadine practically does not interact with other drugs and does not have a cardiotoxic effect.

The following antihistamines are topical preparations and are intended to relieve local manifestations of allergies.

Azelastine(Allergodil) is a highly effective remedy for the treatment of allergic rhinitis and conjunctivitis. Used as a nasal spray and eye drops, azelastine is practically devoid of systemic action.

cetirizine(Zyrtec) is a highly selective peripheral H1 receptor antagonist. It is an active metabolite of hydroxyzine, which has a much less pronounced sedative effect. Cetirizine is almost not metabolized in the body, and the rate of its excretion depends on the function of the kidneys. Its characteristic feature is its high ability to penetrate the skin and, accordingly, its effectiveness in skin manifestations of allergies. Cetirizine neither in the experiment nor in the clinic showed any arrhythmogenic effect on the heart.

findings

So, in the doctor's arsenal there is a sufficient amount of antihistamines with different properties. It must be remembered that they provide only symptomatic relief from allergies. In addition, depending on the specific situation, you can use both different drugs and their diverse forms. It is also important for the physician to be aware of the safety of antihistamines.

The disadvantages of most 1st generation antihistamines include the phenomenon of tachyphylaxis (addiction), requiring a change of the drug every 7-10 days, although, for example, dimethindene (Fenistil) and clemastine (Tavegil) have been shown to be effective for 20 days without the development of tachyphylaxis ( Kirchhoff C. H. et al., 2003; Koers J. et al., 1999).

The duration of action is from 4-6 hours for diphenhydramine, 6-8 hours for dimethindene, up to 12 (and in some cases 24) hours for clemastine, so the drugs are prescribed 2-3 times a day.

Despite the above disadvantages, 1st generation antihistamines occupy a strong position in allergological practice, especially in pediatrics and geriatrics (Luss L.V., 2009). The presence of injectable forms of these drugs makes them indispensable in acute and urgent situations. The additional anticholinergic effect of chloropyramine significantly reduces itching and skin rashes in atopic dermatitis in children; reduces the volume of nasal secretion and relief of sneezing in ARVI. The therapeutic effect of 1st generation antihistamines in sneezing and coughing can be largely due to the blockade of H1- and muscarinic receptors. Cyproheptadine and clemastine, along with antihistamine action, have a pronounced antiserotonin activity. Dimentiden (Fenistil) additionally inhibits the action of other allergy mediators, in particular kinins. Moreover, the cost of 1st generation antihistamines has been found to be lower than that of 2nd generation antihistamines.

The effectiveness of oral antihistamines of the 1st generation is indicated, their use in combination with oral decongestants in children is not recommended.

Therefore, the advantages of 1st generation antihistamines are: long experience (over 70 years) of use, good study, the possibility of dosed use in infants (for dimethindene), indispensability in acute allergic reactions to food, drugs, bites insects, during premedication, in surgical practice.

Features of 2nd generation antihistamines are high affinity (affinity) for H1 receptors, duration of action (up to 24 hours), low permeability through the blood-brain barrier in therapeutic doses, no inactivation of the drug by food, no tachyphylaxis. In practice, these drugs are not metabolized in the body. They do not cause the development of a sedative effect, however, some patients may experience drowsiness when using them.

The benefits of 2nd generation antihistamines are as follows:

• Due to their lipophobicity and poor penetration through the blood-brain barrier, 2nd generation drugs have practically no sedative effect, although it can be observed in some patients.
• The duration of action is up to 24 hours, so most of these drugs are prescribed once a day.
• Lack of addiction, which makes it possible to prescribe for a long time (from 3 to 12 months).
• After discontinuation of the drug, the therapeutic effect may last for a week.

Antihistamines of the 2nd generation are characterized by anti-allergic and anti-inflammatory effects. Certain anti-allergic effects have been described, but their clinical significance remains unclear.

Long-term (years) therapy with oral antihistamines, both first and second generation, is safe. Some, but not all, drugs in this group are metabolized in the liver by the cytochrome P450 system and may interact with other drugs. The safety and efficacy of oral antihistamines in children has been established. They can be prescribed even to small children.

Thus, having such a wide range of antihistamines, the doctor has the opportunity to choose a drug depending on the patient's age, specific clinical situation, and diagnosis. Antihistamines of the 1st and 2nd generation remain an integral part of the complex treatment of allergic diseases in adults and children.

Literature

1. Gushchin I.S. Antihistamines. A guide for doctors. M.: Aventis Pharma, 2000, 55 p.
2. Korovina N. A., Cheburkin A. V., Zakharova I. N., Zaplatnikov A. L., Repina E. A. Antihistamines in the practice of a pediatrician. Handbook for doctors. M., 2001, 48 p.
3. Luss L.V. The choice of antihistamines in the treatment of allergic and pseudo-allergic reactions // Ros. allergological journal. 2009, no. 1, p. 1-7.
4. ARIA // Allergy. 2008. V. 63 (Suppl. 86). P. 88-160
5. Gillard M., Christophe B., Wels B., Chaterlian P., Peck M., Massingham R. Second generation H1 antagonists potency versus selectivity // Annual Meeting of The European Hisamine Research Society, 2002, 22 may, Eger, Hungary.

O. B. Polosyants, Candidate of Medical Sciences

City Clinical Hospital No. 50, Moscow

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 effects 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

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 of 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)

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 magnitude of creatinine clearance: in mild renal failure, 10 mg of an antihistamine drug is prescribed 1 time per 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 of carbohydrate metabolism (glucose-galactose malabsorption syndrome and others).

Cetirizine, taken at normal doses, may cause temporary adverse reactions such as fatigue, drowsiness, central nervous system agitation, 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 the increased risk of 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)

Presentation: film-coated tablets, oral drops, 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, drinking plenty of 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.