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Antihistamines 1st, 2nd and 3rd generation

Antihistamines are substances that suppress the action of free histamine. When ingested, the allergen, histamine is released from mast cells in connective tissue within the body's immune system. He begins to interact with specific receptors and cause itching, swelling, rash and other allergic reactions. For blocking these receptors respond to antihistamines. There are three generations of these drugs.


Contents:

Antihistamines 1st generation

They appeared in 1936 and continued to be used. These medicines come in reversible communication with the H1 receptors, which explains the need for a large quantity and high frequency techniques.

Antihistamines 1st generation are characterized by the following pharmacological properties:

  • reduce muscle tone;
  • have a sedative, hypnotic and anticholinergic effects;
  • potentiate the effects of alcohol;
  • have a local anesthetic effect;
  • give fast and strong, but short-term (4-8 hours) therapeutic effect;
  • long reception reduces antihistaminic activity, so every 2-3 weeks means change.

The bulk of antihistamines 1st generation fat soluble, can cross the blood-brain barrier and to reach H1-receptors in the brain, which explains the sedative effect of these drugs, which is enhanced after taking alcohol or psychotropic drugs. When receiving the average therapeutic dose of children and is highly toxic adults may experience psychomotor agitation. Due to sedative effect, antihistamines 1st generation is not granted to persons whose work requires special attention.

Anticholinergic properties of these drugs cause atropine reactions such as tachycardia, dryness of the throat and mouth, urinary retention,constipation, blurred vision. These features can be useful for rhinitis, but is able to potentiate the airway obstruction caused by bronchial asthma (it increases the viscosity of sputum), contribute to the exacerbation of benign prostatic hyperplasia, glaucoma, and other diseases. At the same time these drugs have antiemetic and protivokashlevami effect, reduce the manifestation of parkinsonism.

A number of these antihistamines is included in the combined funds, which are used for migraines, colds, motion sickness or have a calming or sedative effect.

Extensive list of side effects from taking antihistamine substances data rarely forced to use them in the treatment of allergic diseases. Many developed countries have prohibited their implementation.

Diphenhydramine

Diphenhydramine is prescribed for hay fever, urticaria, sea, air sickness, vasomotor rhinitis, bronchial asthma, allergic reactions caused by administration of drugs (e.g., antibiotics) in the treatment of peptic ulcer, dermatoses, etc.

  • Advantages: high anti-histamine activity, reducing the severity of allergic, pseudoallergic reactions. Diphenhydramine has antitussive and antiemetic effects, has local anesthetic effect, so is an alternative to Novocaine and Lidocaine in their intolerance.
  • Cons: unpredictability of effects of the drug, its effects on the Central nervous system. It can cause urinary retention and dry mucous membranes. Side effects include a sedative and hypnotic effects.

The pain

The treatment has the same indications as other antihistamines, but differs from them by the peculiarities of the impact.

  • Advantages: mild sedative effect allows you to apply it where it is undesirable to have a CNS depressant effect.
  • Cons: irritates the mucous membranes of the gastrointestinal tract, cause dizziness, impaired urination, drowsiness, slowing of mental and motor responses. There is information about the toxic effects of the drug on nerve cells.

Suprastin

Suprastin is prescribed for the treatment of seasonal and chronic allergic conjunctivitis, urticaria,atopic dermatitis, angioedema, pruritus of various etiology, eczema. It is used in parenteral form when requiring urgent assistance with acute allergic conditions.

  • Advantages: serum does not accumulate, therefore, even after prolonged use not cause an overdose. Due to the high antihistamine activity, there has been a rapid therapeutic effect.
  • Cons: side effects – drowsiness, dizziness, slow reactions, etc. – are present, although less pronounced. The therapeutic effect of short-term, to renew it, Suprastin combined with H1-blockers non-sedating properties.

Tavegil

Tavegil in the form of injections used in angioneurotic edema, and anaphylactic shock, as a prophylactic and therapeutic agent for allergic and pseudoallergic reactions.

  • Advantages: provides a longer and stronger antihistaminic action than Diphenhydramine, and has a moderate sedative impact.
  • Cons: can cause an allergic reaction, it has a slow down effect.

Fenkarol

Fenkarol administered with the appearance of addiction to other antihistamine drugs.

  • Advantages: has a weak expression of sedative properties, it has pronounced CNS depressant action, low toxicity, blocks the H1 receptors, is able to reduce the content in the tissues of histamine.
  • Cons: less antihistamine activity compared with Diphenhydramine. Fenkarol with caution applies if you have diseases of the gastrointestinal tract, cardiovascular system and liver.

Antihistamines 2nd generation

They have the advantages in comparison with drugs of the first generation:

  1. missing a sedative and holinoliticheskoe effect, since these drugs do not overcome the blood-brain barrier, only some individuals experience mild drowsiness;

  2. mental activity, physical activity not affected;

  3. the drugs up to 24 hours, therefore taking times a day;

  4. they are not addictive, which allows you to assign them for a long time (3-12months);

  5. when stopping drugs, the therapeutic effect lasts about a week;

  6. medicines are absorbed from food in the digestive tract.

But antihistamines 2nd generation have a cardiotoxic effect of various degrees, so at their reception under the control of the cardiac activity. They are contraindicated in older patients and patients suffering from disorders of the cardiovascular system.

The occurrence of cardiotoxicity due to the ability of antihistamines 2nd generation block potassium channels of the heart. The risk is enhanced when these tools combine with anti-fungal drugs, macrolides, anti-depressants, drinking grapefruit juice, and when patient has expressed violations of the liver.

Klaridol and sucking

Klaridol used to treat seasonal and cyclical allergic rhinitis, urticaria, allergic conjunctivitis, angioedema and other diseases with allergic origin. He is coping with allergic symptoms and allergies to insect bites. Included in comprehensive measures for the treatment of itching dermatoses.

  • Advantages: Klaridol has antipruritic, anti-allergic, protivoekssoudative action. The drug reduces capillary permeability, prevents the development of edema, relieves spasms of smooth muscles. It has no effect on the Central nervous system, has no holinoblokirutego and sedation.
  • Cons: occasionally after taking Klaridol patients complain of dry mouth, nausea and vomiting.

Klarotadina

Klarotadina contains the active ingredient loratadine, which is a selective blocker of H1-histamine receptors, to which it has a direct impact, allowing you to avoid unwanted effects of other antihistamines drugs. Indications for use are allergic conjunctivitis, acute and chronic idiopathic urticaria, rhinitis, pseudoallergic reactions associated with histamine release, allergic to insect bites, itchy dermatitis.

  • Advantages: the drug has no sedative effects, is not addictive, works fast and for a long time.
  • Cons: unintended consequences of receiving Claroline include disorders of the nervoussystem: asthenia, anxiety, drowsiness, depression, amnesia, tremor, agitation in children. The skin may appear dermatitis. Frequent and painful urination, constipation, and diarrhea. Weight gain due to disruption of the endocrine system. The defeat of the respiratory system may include coughing, bronchospasm, sinusitis and similar manifestations.

Lomilan

Lomilan shown in allergic runny nose (rhinitis), seasonal and permanent, skin rash allergic origin, pseudoallergic, reactions to insect bites, allergic inflammation of the mucous membrane of the eyeball.

  • Advantages: Lomilan is able to relieve itch, to reduce the tone of smooth muscles and secretion of fluid (a special fluid that appears when the inflammatory process), prevent tissue edema after only half an hour since the adoption of the drug. The greatest effectiveness occurs within 8-12 hours, and then subsides. Lomilan is not addictive and has no negative effects on the nervous system.
  • Cons: side effects rarely occur headache, fatigue and drowsiness, inflammation of the gastric mucosa, nausea.

Loragexal

Loragexal recommended for year-round and seasonal allergic rhinitis, conjunctivitis, itching dermatoses, urticaria, angioedema, allergic insect bites and various allergic reactions.

  • Advantages: the drug has neither anticholinergic nor the Central action, and its reception has no effect on attention, psychomotor functions, performance, and mental qualities of the patient.
  • Cons: Loragexal generally well tolerated, but occasionally it causes fatigue, dry mouth, headache, tachycardia, dizziness, allergic reactions, coughing, vomiting, gastritis, violation of the liver.

Claritin

Claritin contains the current component – loratadine blocking H1-histamine receptors and prevent histamine, and serotonin bradykinin. Antihistamine effectiveness lasts a day, and therapeutic occurs after 8-12 hours. Claritin is indicated for the treatment of rhinitis of allergic etiology, allergic skin reactions, food allergies and mild asthma.

  • Advantages: high efficiency in the treatment of allergic diseases, the drug is not addictive,drowsiness.
  • Cons: the side effects are rare, they are manifested by nausea, headache, gastritis, agitation, allergic reactions, drowsiness.

Ruppin

Ruppin has a unique active ingredient – rupatadine, characterized antihistamine activity and a selective action on the H1 histamine peripheral receptors. It is prescribed for chronic idiopathic urticaria and allergic rhinitis.

  • Advantages: Ruppin effectively cope with the symptoms listed above, allergic diseases and has no effect on the functioning of the CNS.
  • Cons: the unintended consequences of the drug – asthenia, dizziness, fatigue, headache, drowsiness, dry mouth. It can affect the respiratory, nervous, musculoskeletal and digestive system, as well as on metabolism and skin.

Zyrtec

Zyrtec – competitive antagonist metabolite gidroxizina, histamine. The drug facilitates the flow and sometimes prevents the development of allergic reactions. Zyrtec restricts the release of mediators, reduces migration of eosinophils, basophils, neutrophils. A drug used in allergic rhinitis, asthma, urticaria, conjunctivitis, dermatitis, fever, skin itching, angioneurotic edema.

  • Advantages: effectively prevents edema, reduces capillary permeability, eliminates spasm of smooth muscles. Zyrtec does not have anticholinergic and antiserotonin action.
  • Cons: incorrect use of the drug may lead to dizziness, headaches, drowsiness, allergic reactions.

Kestin

Kestin blocks histamine receptors that increase the permeability of blood vessels, causing muscle spasms that lead to manifestation of allergic reaction. It is used to treat allergic conjunctivitis, rhinitis and chronic idiopathic urticaria.

  • Advantages: the drug acts within an hour after application, the therapeutic effect lasts 2 days. Five-day admission Cestina allows you to save antihistamine effect about 6 days. Sedative effect almost does not occur.
  • Cons: the application Cestina can cause insomnia, abdominal pain, nausea, drowsiness,asthenia, headache, sinusitis, dry mouth.

Antihistamines new, 3rd generation

These substances are prolekarstvom, this means that, once in the body, they are from the original form is converted to pharmacologically active metabolites.

All antihistamines 3 generations do not have cardiotoxic and sedative effect, so they can apply persons whose activity is connected with high concentration.

These drugs block the H1 receptors and have additional effects on allergic manifestations. They have high selectivity and does not overcome the blood-brain barrier, so it is not peculiar to negative consequences in the Central nervous system is no side effects on the heart.

The presence of additional effects contributes to the use of antihistamines for 3 generations, with long-term treatment of most allergic reactions.

Hismanal

Hismanal is designated as curative and preventive remedies for hay fever, allergic skin reactions, including urticaria, allergic rhinitis. The effect of the drug develops within 24 hours and reaches its maximum after 9-12 days. Its duration depends on previous therapy.

  • Advantages: the drug has virtually no sedative effect, not enhances the effect from taking sleeping pills or alcohol. It also does not affect ability to drive or mental activity.
  • Cons: Hismanal may cause increased appetite, dry mucous membranes, tachycardia, drowsiness, arrhythmia, prolonged QT interval, heart rate, and collapse.

Was trexel

Was trexel – it's fast selectively active antagonist of H1-receptor-derived butirofenona, having a different chemical structure from peers. Used in allergic rhinitis to relieve symptoms, allergic dermatologic manifestations (dermographism, contact dermatitis, urticaria, atopiceczema), asthma, atonic and provoked by exercise, as well as in connection with acute allergic reactions to various stimuli.

  • Advantages: absence of sedation and antiholinergicescoe effect, effect on psychomotor performance and wellbeing. The drug is safe to use by patients with glaucoma and suffering from prostate disorders.
  • Cons: if you exceed the recommended dosage was observed mild sedative effect and also reaction on the part of the digestive tract, skin and respiratory tract.

Telfast

Telfast – a highly effective antihistamine, which is a metabolite of terfenadine, therefore, has great similarity with the H1-receptors of histamine. Telfast binds to them and blocks, preventing their biological manifestations as allergic symptoms. Stabiliziruemost the membranes of fat cells and decreases the release of histamine from them. Indications for use is angioedema, hives, hay fever.

  • Advantages: does not show sedative properties, does not affect reaction speed and concentration, the heart, not addictive, highly effective against the symptoms and causes of allergic diseases.
  • Cons: the rare effects of the drug are headache, nausea, dizziness, rarely shortness of breath, anaphylactic reaction, flushing of the skin.

Fixedin

The drug is used for the treatment of seasonal allergic rhinitis with the following manifestations of hay fever: itching, sneezing, rhinitis, redness of the mucous membrane of the eye, as well as for the treatment of chronic idiopathic urticaria and its symptoms: itching, redness.

  • Benefits – while taking the drug do not manifest side effects common to antihistamines: blurred vision, constipation, dry mouth, weight gain, negative effect on the heart muscle. The drug can be purchased at the pharmacy without a prescription, is not necessary to adjust the dose for elderly patients, and renal and hepatic insufficiency. The drug acts quickly, saving his action during the day. The drug is not too high, it is available to many people suffering fromAllergy.

  • Disadvantages – some time later, perhaps addictive to the drug, it has side effects: dyspepsia, dysmenorrhoea, tachycardia, headache, and dizziness, anaphylactic reaction, dysgeusia. Can form a dependence on the drug.

Teksoft

The drug is administered at the appearance of seasonal allergic rhinitis and chronic urticaria.

  • Advantages – the drug is rapidly absorbed, reaching therapeutic after an hour after taking this action continues during the day. His method does not require restrictions for the people who operated the complex mechanisms driving cars does not cause sedation. Teksoft without prescription, it has a reasonable price, manifests itself high efficiency.

  • Disadvantages – some patients on the drug brings only temporary relief, without complete recovery from the symptoms of allergies. It has side effects: swelling, increased sleepiness, nervousness, insomnia, headache, weakness, increased Allergy symptoms such as skin itching, skin rash.

Levocetirizine Teva

The drug is prescribed for the symptomatic treatment of hay fever (pollinosis), urticaria, allergic rhinitis and allergic conjunctivitis with itching, lacrimation, conjunctival hyperemia, skin rashes and rashes, angioedema.

  • Advantages – Levocetirizine-Teva quickly shows its efficiency (using 12-60 minutes) and during the day prevent the appearance and reduces the occurrence of allergic reactions. The drug is rapidly absorbed, showing 100% bioavailability. Can be used for long-term treatment and for emergency care during seasonal allergic exacerbations. Available for the treatment of children 6 years of age.

  • Disadvantages – has side effects such as drowsiness, irritability, nausea, headache, weight gain, tachycardia, abdominal pain, angioedema, migraine. The price of medicine is high enough.

Xyzal

The drug is used for the symptomatic treatment of these symptoms of hay fever and hives, as itching, sneezing, conjunctival irritation, rhinorrhea, angioedema, allergic dermatitis.

  • Advantages – Xyzal has a pronounced anti-orientation, being a very effective tool. It prevents the occurrence of Allergy symptoms, facilitates the flow, has no sedative effect. The drug is very fast acting, keeping your effect on the day after admission. Xyzal can be used to treat children from 2 years, it is available in two dosage forms (tablets, drops) suitable for use in Pediatrics. It eliminates nasal congestion, the symptoms of chronic allergies quickly cropped, has no toxic effect on the heart and Central nervous system

  • Disadvantages – not recommended during treatment with Kisala to drive the vehicle because of the sedative effect. The tool can show the following side effects: dry mouth, fatigue, abdominal pain, pruritus, hallucinations, shortness of breath, hepatitis, convulsions, muscle pain.

Aerius

The drug is indicated for the treatment of seasonal hay fever, allergic rhinitis, chronic idiopathic urticaria with symptoms such as watery eyes, coughing, itching, swelling of the mucous membrane of the nasopharynx.

  • Advantages – extremely fast acting Aerius for Allergy symptoms, it can be used for the treatment of children with year, as it has a high degree of security. Well tolerated, as adults, and children, is available in several dosage forms (tablets, syrup), which is very convenient for use in Pediatrics. Can be taken over a long time period (up to years) without causing addiction (resistance to it). Reliably relieves the symptoms of the initial phase of allergic response. After treatment the effect of it persists for 10-14 days. Overdose symptoms are not observed even at the fivefold increase in dose Aerius.

  • Disadvantages – can appear side effects (nausea and vomiting, headache, tachycardia, local allergic symptoms, diarrhea, hyperthermia). Children usually get insomnia, headache, fever.

Desal

The drug is designed to treat suchmanifestations of Allergy like allergic rhinitis and hives marked by itching and skin eruptions. The drug relieves the symptoms of allergic rhinitis like sneezing, itchy nose and in the palate, watery eyes.

  • Advantages – Desal prevents the appearance of edema, spasm of the muscles, reduces capillary permeability. The effect of the drug can be noticed within 20 minutes that persists for days. Is very convenient single dose of medication, two forms of its release, syrup and tablets, the reception of which does not depend on food. Because Desal take to treat children from 12 months form release medications in the form of syrup demand. The drug is so safe that even a 9-fold excess dose does not lead to negative symptoms.

  • Disadvantages – can occasionally manifest such symptoms of side effects like fatigue, headache, dryness of the oral mucosa. Further exhibits such side effects as insomnia, tachycardia, appearance of hallucinations, diarrhea, hyperactivity. Allergic reactions possible side effects: itching, hives, angioedema.


Antihistamines 4th generation – do they exist?

All the claims of the creators of the ads, positioning brand medicines as "antihistamines are the fourth generation", is nothing more than a publicity stunt. This pharmacological group does not exist, although marketers refer to it not only re-established drugs, but the drugs of the second generation.

Official classification indicates only two groups of antihistamines are drugs of first and second generation. The third group of pharmacologically active metabolites, especially in pharmaceuticals, as "H1 histamine antagonists of the third generation".


Antihistamines for children

For the treatment of allergic manifestations among children using antihistamines all three generations.

Antihistamines 1st generation differ that quickly show its medicinal property and removed from the body. They are popular for the treatment of acute manifestations of allergic reactions. They are assigned short courses. The most effective of this group is considered Tavegil, Suprastin, Diazolin, Fenkarol.

A significant percentage of side effects leads to a decrease in the use of these drugs in pediatric Allergy.

Antihistamines 2nd generation does not causesedation, act a longer time and they are used usually once a day. Few side-effects. Among this group of drugs for the treatment of manifestations of pediatric Allergy Ketotifen use, Fenistil, this really Helps.

3 generation antihistamines for children includes Hismanal, Terpen and others. They are used in chronic allergic processes, as they are able to be a long time in the body. No side effects.

The newer drugs include the Aerius.

Negative consequences:

  • 1st generation: headache, constipation, tachycardia, drowsiness, dry mouth, blurred vision, urinary retention and lack of appetite;
  • 2 generation: the negative impact on the heart and the liver;

  • 3rd generation are recommended for use from 3 years.

For kids release antihistamines in the form of ointments (allergic reaction on the skin), drops, syrups and tablets for oral administration.


Antihistamines in pregnancy

In the first trimester of pregnancy are prohibited from taking antihistamines. In the second, they are prescribed only in extreme cases because none of these remedies is not completely secure.

To help relieve some allergic symptoms can natural antihistamines, which include vitamins C, B12, Pantothenic, oleic acid and nicotinic acid, zinc, fish oil.

The most safe antihistamines – claritin, Zyrtec, Telfast, Avil, but their application should be mandatory agreed with the doctor.