Antihistamines (list) 1, 2 And New 3 Generations - For Children And During Pregnancy

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Antihistamines 1st, 2nd and 3rd generation

Antihistamines are substances that inhibit the action of free histamine. When an allergen enters the body, histamine is released from the mast cells of the connective tissue that are part of the body's immune system. It begins to interact with specific receptors and cause itching, swelling, rash, and other allergic manifestations. Antihistamines are responsible for blocking these receptors. There are three generations of these drugs.

Content:

• 1st generation antihistamines
• 2nd generation antihistamines
• Antihistamines 3rd generation
• 4th generation antihistamines - do they exist?
• Antihistamines for children
• Antihistamines during pregnancy
• 4 of the best natural antihistamines

1st generation antihistamines

They appeared in 1936 and continue to be used. These drugs enter into a reversible relationship with H1 receptors, which explains the need for high dosage and high frequency of administration.

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

• reduce muscle tone;
• have a sedative, hypnotic and anticholinergic effect;
• potentiate the effects of alcohol;
• have a local anesthetic effect;
• give a quick and strong, but short-term (4-8 hours) therapeutic effect;
• long-term use reduces antihistamine activity, so every 2-3 weeks the funds are changed.

The bulk of 1st generation antihistamines are fat-soluble, they can cross the blood-brain barrier and bind to H1 receptors in the brain, which explains the sedative effect of these drugs, which increases after taking alcohol or psychotropic drugs. When taking medium therapeutic doses by children and high toxic ones by adults, psychomotor agitation can be observed. Due to the sedative effect, 1st generation antihistamines are not prescribed for persons whose activities require increased attention.

The anticholinergic properties of these drugs cause atropine-like reactions such as tachycardia, dryness of the nasopharynx and oral cavity, urinary retention, constipation, and visual impairment. These features may be beneficial for rhinitis, but they can exacerbate airway obstruction caused by bronchial asthma (increased viscosity of sputum), exacerbate prostate adenoma, glaucoma and other diseases. At the same time, these drugs have an antiemetic and anti-pumping effect, reduce the manifestation of parkinsonism.

A number of these antihistamines are included in combination drugs that are used for migraines, colds, motion sickness, or have a sedative or hypnotic effect.

The extensive list of side effects from taking these antihistamines makes them less likely to be used in the treatment of allergic diseases. Many developed countries have banned their implementation.

Diphenhydramine

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

• Advantages: high antihistamine activity, reduced severity of allergic, pseudo-allergic reactions. Diphenhydramine has an antiemetic and antitussive effect, has a local anesthetic effect, making it an alternative to Novocaine and Lidocaine in case of intolerance.
• Cons: the unpredictability of the consequences of taking the drug, its effect on the central nervous system. It can cause urinary retention and dry mucous membranes. Side effects include sedative and hypnotic effects.

Diazolin

Diazolin has the same indications for use as other antihistamines, but differs from them in the features of the effect.

• Advantages: a mild sedative effect allows its use where it is undesirable to exert a depressing effect on the central nervous system.

• Cons: irritates the mucous membranes of the gastrointestinal tract, causes dizziness, impaired urination, drowsiness, slows down mental and motor reactions. 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, Quincke's edema, itching of various etiologies, eczema. It is used in parenteral form for acute allergic conditions requiring urgent help.

• Advantages: it does not accumulate in blood serum, therefore, even with prolonged use, it does not cause an overdose. Due to its high antihistamine activity, a quick healing effect is observed.
• Cons: side effects - drowsiness, dizziness, inhibition of reactions, etc. - are present, although they are less pronounced. The therapeutic effect is short-term, in order to prolong it, Suprastin is combined with H1-blockers that do not have sedative properties.

Tavegil

Tavegil in the form of injections is used for angioedema, as well as anaphylactic shock, as a prophylactic and therapeutic agent for allergic and pseudo-allergic reactions.

• Benefits: It has a longer and stronger antihistamine effect than diphenhydramine, and has a milder sedative effect.
• Cons: it can itself cause an allergic reaction, has some inhibitory effect.

Fenkarol

Fenkarol is prescribed when addiction to other antihistamines appears.

• Advantages: it has a weak severity of sedative properties, does not have a pronounced inhibitory effect on the central nervous system, is low toxic, blocks H1 receptors, is able to reduce the content of histamine in tissues.
• Cons: less antihistaminic activity in comparison with diphenhydramine. Fenkarol is used with caution in the presence of diseases of the gastrointestinal tract, cardiovascular system and liver.

2nd generation antihistamines

They have advantages over first generation drugs:

1. there is no sedative and anticholinergic effect, since these drugs do not cross the blood-brain barrier, only some people experience moderate drowsiness;
2. mental activity, physical activity do not suffer;
3. the action of the drugs reaches 24 hours, so they are taken once a day;
4. they are not addictive, which allows them to be prescribed for a long time (3-12 months);
5. when you stop taking drugs, the therapeutic effect lasts about a week;
6. drugs are not adsorbed with food in the gastrointestinal tract.

But antihistamines of the 2nd generation have a cardiotoxic effect of varying degrees, therefore, when they are taken, cardiac activity is monitored. They are contraindicated in elderly patients and patients suffering from disorders of the cardiovascular system.

The occurrence of a cardiotoxic effect is explained by the ability of 2nd generation antihistamines to block the potassium channels of the heart. The risk is increased when these drugs are combined with antifungal drugs, macrolides, antidepressants, from drinking grapefruit juice, and if the patient has severe liver dysfunctions.

Claridol and Clarisens

Claridol is used to treat seasonal as well as cyclic allergic rhinitis, urticaria, allergic conjunctivitis, Quincke's edema and a number of other diseases of allergic origin. It copes with pseudo-allergic syndromes and insect bite allergies. It is included in the complex measures for the treatment of itchy dermatoses.

• Benefits: Claridol has antipruritic, anti-allergic, anti-exudative effects. The drug reduces capillary permeability, prevents the development of edema, relieves spasm of smooth muscles. It has no effect on the central nervous system, has no anticholinergic and sedative effect.
• Cons: Occasionally, after taking Claridol, patients complain of dry mouth, nausea and vomiting.

Clarotadine

Clarotadine contains the active substance loratadine, which is a selective blocker of H1-histamine receptors, on which it has a direct effect, allowing you to avoid the undesirable effects inherent in other antihistamines. Indications for use are allergic conjunctivitis, acute chronic and idiopathic urticaria, rhinitis, pseudo-allergic reactions associated with the release of histamine, allergic insect bites, itchy dermatoses.

• Advantages: the drug does not have a sedative effect, does not cause addiction, and acts quickly and for a long time.
• Cons: the undesirable consequences of taking Clarodin include disorders of the nervous system: asthenia, anxiety, drowsiness, depression, amnesia, tremor, agitation in a child. Dermatitis may appear on the skin. Frequent and painful urination, constipation and diarrhea. Weight gain due to endocrine disruption. Damage to the respiratory system can be manifested by coughing, bronchospasm, sinusitis, and similar manifestations.

Lomilan

Lomilan is indicated for seasonal and persistent allergic rhinitis (rhinitis), skin rashes of allergic genesis, pseudo-allergies, reactions to insect bites, allergic inflammation of the mucous membrane of the eyeball.

• Advantages: Lomilan is able to relieve itching, reduce the tone of smooth muscles and the production of exudate (a special fluid that appears during the inflammatory process), prevent tissue edema after half an hour after taking the drug. The greatest effectiveness occurs after 8-12 hours, then subsides. Lomilan is not addictive and does not negatively affect the activity of the nervous system.
• Cons: side reactions are rare, manifested by headache, feeling of fatigue and drowsiness, inflammation of the gastric mucosa, nausea.

LauraHexal

LoraGeksal is recommended for year-round and seasonal allergic rhinitis, conjunctivitis, itchy dermatoses, urticaria, Quincke's edema, allergic insect bites and various pseudo-allergic reactions.

• Advantages: the drug has neither anticholinergic, nor central action, its intake does not affect the attention, psychomotor functions, performance and mental qualities of the patient.
• Cons: LauraHeksal is usually well tolerated, but occasionally it causes fatigue, dry mouth, headache, tachycardia, dizziness, allergic reactions, cough, vomiting, gastritis, liver dysfunction.

Claritin

Claritin contains an active ingredient - loratadine, which blocks H1-histamine receptors and prevents the release of histamine, bradykinin and serotonin. Antihistamine efficacy lasts a day, and therapeutic efficacy occurs after 8-12 hours. Claritin is prescribed for the treatment of allergic rhinitis, allergic skin reactions, food allergies and mild bronchial asthma.

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

Rupafin

Rupafin has a unique active ingredient, rupatadin, which is characterized by antihistamine activity and selective action on H1-histamine peripheral receptors. It is prescribed for chronic idiopathic urticaria and allergic rhinitis.

• Benefits: Rupafin effectively treats the symptoms of the above allergic diseases and does not affect the central nervous system.
• Cons: undesirable consequences of taking the drug - asthenia, dizziness, fatigue, headache, drowsiness, dry mouth. It can affect the respiratory, nervous, musculoskeletal and digestive systems, as well as metabolism and skin.

Zyrtec

Zyrtec is a competitive antagonist of the hydroxyzine metabolite, histamine. The drug facilitates the course and sometimes prevents the development of allergic reactions. Zyrtec limits the release of mediators, reduces the migration of eosinophils, basophils, neutrophils. The drug is used for allergic rhinitis, bronchial asthma, urticaria, conjunctivitis, dermatitis, fever, pruritus, angioedema.

• Advantages: effectively prevents the occurrence of edema, reduces capillary permeability, relieves spasm of smooth muscles. Zyrtec does not have anticholinergic and antiserotonin effects.
• Cons: improper use of the drug can lead to dizziness, migraine, drowsiness, allergic reactions.

Kestin

Kestin blocks histamine receptors that increase vascular permeability, causing muscle spasms, leading to an allergic reaction. It is used to treat allergic conjunctivitis, rhinitis and chronic idiopathic urticaria.

• Advantages: the drug acts an hour after application, the therapeutic effect lasts 2 days. A five-day intake of Kestin allows you to maintain the antihistamine effect for about 6 days. Sedation is almost never found.
• Cons: The use of Kestin can cause insomnia, abdominal pain, nausea, drowsiness, asthenia, headache, sinusitis, dry mouth.

New antihistamines, 3rd generation

These substances are prodrugs, which means that when they enter the body, they are converted from their original form into pharmacologically active metabolites.

All antihistamines of the 3rd generation do not have a cardiotoxic and sedative effect, therefore they can be used by persons whose activities are associated with a high concentration of attention.

These drugs block H1 receptors and also have an additional effect on allergic manifestations. They have high selectivity, do not overcome the blood-brain barrier, therefore, they are not characterized by negative consequences from the central nervous system, there are no side effects on the heart.

The presence of additional effects promotes the use of 3rd generation antihistamines for long-term treatment of most allergic manifestations.

Gismanal

Gismanal is prescribed as a therapeutic and prophylactic agent for hay fever, allergic skin reactions, including urticaria, allergic rhinitis. The effect of the drug develops within 24 hours and reaches a maximum after 9-12 days. Its duration depends on the previous therapy.

• Advantages: the drug has practically no sedative effect, does not enhance the effect of taking sleeping pills or alcohol. It also has no effect on driving ability or mental performance.
• Cons: Gismanal can cause increased appetite, dry mucous membranes, tachycardia, drowsiness, arrhythmia, prolongation of the QT interval, palpitations, collapse.

Trexil

Trexil is a fast-acting selectively active antagonist of H1 receptors, derived from butyrophenone, which differs in chemical structure from analogs. It is used for allergic rhinitis to relieve its symptoms, allergic dermatological manifestations (dermographism, contact dermatitis, urticaria, atonic eczema,), asthma, atonic and provoked physical exertion, as well as in connection with acute allergic reactions to various irritants.

• Advantages: no sedative and anticholinergic effect, no effect on psychomotor activity and human well-being. The drug is safe for use by patients with glaucoma and prostate disorders.
• Cons: when the recommended dosage was exceeded, a weak manifestation of sedation was observed, as well as reactions from the gastrointestinal tract, skin and respiratory tract.

Telfast

Telfast is a highly effective antihistamine, which is a metabolite of terfenadine, therefore it has a great similarity to the histamine H1 receptors. Telfast binds to and blocks them, preventing their biological manifestations as allergic symptoms. The membranes of mast cells are stabilized and the release of histamine from them decreases. Indications for use are Quincke's edema, urticaria, hay fever.

• Advantages: does not show sedative properties, does not affect the speed of reactions and concentration of attention, heart function, is not addictive, highly effective against the symptoms and causes of allergic diseases.
• Cons: rare consequences of taking the drug are headache, nausea, dizziness, shortness of breath, anaphylactic reaction, skin hyperemia are extremely rare.

Feksadin

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

• Advantages - when taking the drug, the side effects characteristic of antihistamines do not appear: visual impairment, constipation, dry mouth, weight gain, negative effect on the work of the heart muscle. The drug can be purchased over the counter without a prescription; no dose adjustment is required for the elderly, patients, and renal and hepatic impairment. The drug acts quickly, maintaining its effect during the day. The price of the drug is not too high, it is available to many people suffering from allergies.
• Disadvantages - after some time, it is possible to get used to the action of the drug, it has side effects: dyspepsia, dysmenorrhea, tachycardia, headache and dizziness, anaphylactic reactions, taste perversion. Drug dependence may develop.

Fexofast

The drug is prescribed for the appearance of a seasonal allergic rhinitis, as well as for chronic urticaria.

• Advantages - the drug is rapidly absorbed, reaching the desired level within an hour after administration, this effect continues throughout the day. Its reception does not require restrictions for people who control complex mechanisms, driving vehicles, does not cause sedation. Fexofast is sold without a prescription, has an affordable price, and is highly effective.
• Disadvantages - for some patients, the drug brings only temporary relief, not bringing a complete recovery from the manifestations of allergies. It has side effects: swelling, increased drowsiness, nervousness, insomnia, headache, weakness, increased allergy symptoms in the form of itching, skin rash.

Levocetirizine-Teva

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

• Benefits - Levocytirizin-Teva quickly shows its effectiveness (after 12-60 minutes) and during the day it prevents the appearance and weakens the course of allergic reactions. The drug is rapidly absorbed, showing 100% bioavailability. It can be used for long-term treatment and for emergency treatment of seasonal exacerbations of allergies. Available for the treatment of children from 6 years old.
• Disadvantages - has such side effects as drowsiness, irritability, nausea, headache, weight gain, tachycardia, abdominal pain, Quincke's edema, migraine. The price of the medicine is quite high.

Ksizal

The drug is used for the symptomatic treatment of such manifestations of hay fever and urticaria, such as skin itching, sneezing, inflammation of the conjunctiva, rhinorrhea, Quincke's edema, allergic dermatoses.

• Benefits - Ksizal has a pronounced anti-allergic focus, being a very effective remedy. It prevents the onset of allergy symptoms, relieves their course, and has no sedative effect. The drug acts very quickly, retaining its effect for a day from the moment of administration. Ksizal can be used to treat children from 2 years of age; it is available in two dosage forms (tablets, drops) that are acceptable for use in pediatrics. It eliminates nasal congestion, symptoms of chronic allergies quickly stop, does not have a toxic effect on the heart and the central nervous system
• Disadvantages - the product may exhibit the following side effects: dry mouth, fatigue, abdominal pain, itching, hallucinations, shortness of breath, hepatitis, cramps, muscle pain.

Erius

The drug is indicated for the treatment of seasonal hay fever, allergic rhinitis, chronic idiopathic urticaria with symptoms such as watery eyes, cough, itching, swelling of the nasopharyngeal mucosa.

• Advantages - Erius acts extremely quickly on allergy symptoms, can be used to treat children from one year old, as it has a high degree of safety. Well tolerated by both adults and children, it is available in several dosage forms (tablets, syrup), which is very convenient for use in pediatrics. It can be taken for a long time period (up to a year) without causing addiction (resistance to it). Reliably relieves the manifestations of the initial phase of the allergic response. After the course of treatment, the effect of it lasts for 10-14 days. Overdose symptoms were not noted even with a five-fold increase in the dose of Erius.
• Disadvantages - side effects may appear (nausea and vomiting, headache, tachycardia, local allergic symptoms, diarrhea, hyperthermia). Children usually have insomnia, headache, and fever.

Desal

The drug is intended for the treatment of such manifestations of allergies as allergic rhinitis, and urticaria, marked by itching and skin rashes. The drug relieves symptoms of allergic rhinitis such as sneezing, itching in the nose and palate, lacrimation.

• Benefits - Desal prevents the appearance of edema, muscle spasm, reduces capillary permeability. The effect of taking the drug can be seen after 20 minutes, it lasts for a day. A single dose of the medication is very convenient, two forms of its release are syrup and tablets, the intake of which does not depend on food. Since Desal is taken to treat children starting from 12 months, the syrup form of the drug is in demand. The drug is so safe that even a 9-fold excess of the dose does not lead to negative symptoms.
• Disadvantages - occasionally symptoms of side effects such as fatigue, headache, dryness of the oral mucosa may appear. In addition, side effects such as insomnia, tachycardia, the appearance of hallucinations, diarrhea, hyperactivity are manifested. Allergic side effects are possible: itching, urticaria, angioedema.

4th generation antihistamines - do they exist?

All the claims of advertising creators positioning drug brands as "fourth generation antihistamines" are nothing more than a publicity stunt. This pharmacological group does not exist, although marketers refer to it not only newly created drugs, but also second-generation drugs.

The official classification indicates only two groups of antihistamines - these are the first and second generation drugs. The third group of pharmacologically active metabolites is positioned in pharmaceuticals as “H ₁ histamine blockers of the third generation”.

Antihistamines for children

For the treatment of allergic manifestations in children, antihistamines of all three generations are used.

Antihistamines of the 1st generation differ in that they quickly show their healing properties and are excreted from the body. They are in demand for the treatment of acute manifestations of allergic reactions. They are prescribed in short courses. The most effective of this group is Tavegil, Suprastin, Diazolin, Fenkarol.

A significant percentage of side effects lead to a decrease in the use of these drugs for childhood allergies.

Antihistamines of the 2nd generation do not cause sedation, they act for a longer time and are usually used once a day. Few side effects. Among the drugs in this group, Ketotifen, Fenistil, Tsetrin are used to treat the manifestations of childhood allergies.

The 3rd generation of antihistamines for children includes Gismanal, Terfen and others. They are used for chronic allergic processes, since they are able to stay in the body for a long time. There are no side effects.

Newer drugs include Erius.

Negative consequences:

• 1st generation: headache, constipation, tachycardia, drowsiness, dry mouth, blurred vision, urinary retention and lack of appetite;
• 2nd generation: negative effects on the heart and liver;
• 3rd generation: do not have, are recommended for use from 3 years old.

For children, antihistamines are produced in the form of ointments (allergic reactions on the skin), drops, syrups and tablets for oral administration.

Antihistamines during pregnancy

Antihistamines are prohibited in the first trimester of pregnancy. In the second, they are prescribed only in extreme cases, since none of these remedies is absolutely safe.

Natural antihistamines, which include vitamins C, B12, pantothenic, oleic and niacin, zinc, and fish oil, can help get rid of some allergic symptoms.

The safest antihistamines are Claritin, Zirtek, Telfast, Avil, but their use must also be agreed with a doctor.

4 of the best natural antihistamines

In some cases, you can resort to the help of the following remedies, which can suppress the production of histamine in the body.

1. Nettle. Nettle has antihistamine properties. Freeze-dried nettle powder has been shown to help relieve allergy symptoms. 69 people took part in the experiment using this substance. Of these, 58% of patients noted a significant improvement in well-being. The beneficial effect was achieved with a daily intake of 300 mg of nettle ^[1].
2. Quercetin. Quercetin is an antioxidant known for its anti-inflammatory properties. It is found in some foods such as onions and apples. Scientists are interested in the ability of quercetin to reduce the severity of an allergic reaction ^[2]. They carried out the experiment on rats. Based on its results, it was concluded that quercetin is able to reduce the intensity of allergic rhinitis and inflammation in the respiratory organs ^[3]. For allergy sufferers, you can purchase quercetin supplements or simply consume foods that are rich in this antioxidant.
3. Bromelain. Bromelain is an enzyme found in large quantities in pineapples. There is evidence that it helps to reduce the intensity of allergy symptoms. To have a positive effect, it is recommended to take 400-500 mg of this substance 3 times a day ^[1]. Alternatively, you can simply enrich your diet with pineapples, which hold the record for the content of this substance.
4. Vitamin C. Vitamin C is found in a variety of foods. This antioxidant has properties to suppress the symptoms of an allergic reaction. Vitamin C is non-toxic, its intake in moderate dosages does not harm the human body. Therefore, it can be safely used as an antihistamine. The recommended dose of vitamin C for allergy sufferers is 2 g ^[1].

Foods to help fight allergies

To cope with allergies, you don't have to empty your pharmacy shelves. Sometimes it is enough to minimize contact with the allergen and enrich your menu with products that have antihistamine properties. A proper diet combined with physical activity will help the immune system to resist attacks from the external environment.

As for antioxidants in the form of supplements, you should only take them after consulting a specialist. These substances are best obtained from food. So they will be absorbed 100%.

Links to sources

1. Natural Treatment of Perennial Allergic Rhinitis
2. Quercetin inhibits transcriptional up-regulation of histamine H1 receptor via suppressing protein kinase C -? / Extracellular signal-regulated kinase / poly (ADP-ribose) polymerase-1 signaling pathway in HeLa cells https://www.ncbi.nlm.nih. gov / pubmed / 23333628
3. Anti-inflammatory activity of quercetin and isoquercitrin in experimental murine allergic asthma

Author of the article: Alekseeva Maria Yurievna | Therapist

Education: From 2010 to 2016 Practitioner of the therapeutic hospital of the central medical-sanitary unit No. 21, city of elektrostal. Since 2016 she has been working in the diagnostic center No. 3.