The category of mast cell membrane stabilizing drugs includes topical medications - cromones, as well as systemic drugs with an auxiliary - antihistamine property, namely ketotifen.
The mechanism of action of these medications is that they are able to block the entry of calcium and chlorine ions into the cells, as a result of which the allergy mediator (histamine) is stabilized and the membrane loses the ability to leave this cell. In addition, membrane stabilizers can inhibit the release of other substances that are involved in the development of allergic phenomena.
What it is?
Mast cell membrane stabilizers are drugs that prevent the opening of calcium channels and the penetration of calcium into mast cells. They block the calcium-dependent degranulation of cells and the release of histamine from them - a factor that activates platelets, leukotrienes. They also reduce the manifestations of anaphylaxis and other biologically active substances that can induce inflammatory and allergic reactions. Stabilization of mast cell membranes is determined by the blockade of cAMP accumulation in them and inhibition of phosphodiesterase.
The main aspect of the antiallergic effect of mast cell membrane stabilizing drugs is the increased adrenoreceptor perception of catecholamines. In addition, such drugs have the ability to block the chlorine channels and thus prevent depolarization in the bronchi of parasympathetic endings. They prevent cell infiltration of the mucous membranes of the bronchi and inhibit delayed hypersensitivity reactions. Some of the drugs in this group have the ability to inhibit H1 receptors.
Medications eliminate swelling of the bronchial mucosa and prevent an increase in smooth muscle tone. The main indication for their admission is the prevention of bronchial obstruction.
Effects
The effects of mast cell membrane stabilizing drugs are:
- reduction of excessive mucosal reactivity (due to inhibition of the release of allergic cell reactions from mediators);
- a decrease in the activity of cells that are involved in the development of allergic reactions (eosinophils, macrophages, neutrophils, and others);
- a decrease in the degree of permeability of the mucous membranes - due to a decrease in swelling;
- a decrease in the sensitivity of nerve receptors and the subsequent blocking of the reflex narrowing of the lumens of the bronchi - bronchoconstriction.
What is the mechanism of action of mast cell membrane stabilizers?
Pharmacological properties
The use of drugs of this pharmacological group prevents the development of allergic phenomena (bronchospasm, swelling) during the penetration of potential allergens into the body, as well as under the influence of various provoking factors - physical exertion, cold air and others.
The mast cell membrane stabilizer is Ketotifen. It, like cromons, reduces the increased activity of the respiratory tract in the form of a response to the ingestion of an allergen. In addition, it is a blocker of H1-histamine fibers, that is, it inhibits the progression of allergic processes.
This is the main mechanism of mast cell membrane stabilizers.
In general, membrane stabilizers with their regular prolonged use reduce the frequency of exacerbation of allergic diseases that occur in a chronic form.
Cromones are used to prevent allergic rhinitis and conjunctivitis, bronchial asthma and the development of bronchospasm caused by the influence of provoking factors (physical exertion, cold air and others), as well as before the alleged contact with potential allergens. Among other things, drugs of this pharmacological category are used in the complex treatment of bronchial asthma - in the form of one of the basic therapy medications. To eliminate bronchospasm, these medical products are not used drugs from this classification.
Mast cell membrane stabilizers include Ketotifen. It is used for the prevention of atopic forms of bronchial asthma, treatment of atopic dermatitis, conjunctivitis and rhinitis of an allergic nature, urticaria of a chronic nature. The widespread use of this medication is significantly limited by its relatively low anti-allergic and anti-inflammatory activity, as well as severe side effects of 1st generation antihistamines, which are also characteristic of this drug.
The maximum effectiveness of cromons occurs approximately 14 days after their systematic administration. The duration of such therapy should be 4 months or more. Cancel the drug gradually, over the course of a week.
Addiction during its use is not observed, a decrease in the effectiveness of other medicines with their long-term use (symptoms of tachyphylaxis) is also absent. Are mast cell membrane stabilizers contraindicated?
Contraindications
These funds are contraindicated in the development of asthma attacks. Also, they should not be used in the presence of asthmatic status or hypersensitivity to them.
Inhalation
With inhalation methods of treatment using cromon in some cases, the occurrence of cough and short-term phenomena of bronchospasm is observed, very pronounced bronchospasm develops. Similar reactions are associated with irritation with medications of the mucous membrane of the upper respiratory organs.
What is the clinical pharmacology of mast cell membrane stabilizers, not everyone knows.
Other uses
Using these funds in the form of nasal drops containing cronones, patients in some cases note the appearance of symptoms of cough, headache, taste disturbance and irritation of the mucous membranes of the nasopharynx.
After instillation (instillation in the eyes) of these medications, sometimes there is a burning sensation, a sensation in the eyes of a foreign body, swelling and hyperemia of the conjunctiva (redness).
Negative manifestations
Side effects from the use of "Ketotifen" are equal to H1-histamine blockers of the first generation. In this case, drowsiness, dry mouth, inhibition of the reaction rate and others may occur.
"Sodium Cromoglycate"
This medication also has some analogues, which include:
- "Cromoglycic acid";
- "Ifiral";
- Cromoglin
- Intal
- Cromohexal.
These membrane stabilizers prevent allergic manifestations of immediate action, but do not eliminate them.
When it is inhaled from the airways of the lungs, only 10% of the initial dosage is absorbed, when taken orally, it is even less than 1%, when used intranasally, 8% penetrates the blood, and when instilled into the eyes - 0.04% of the drug .
The maximum concentration of the main substances of the substance in the blood is observed after 15-20 minutes. The effect of instillation into the eyes occurs after 2-14 days, with inhalation after 2-4 weeks, with oral administration after 2-5 weeks.
Indications for the use of this medicine or its analogues are bronchial asthma (as one of the main therapy methods), allergic diseases of the digestive system, food allergy, ulcerative colitis (as an element of the combined treatment), hay fever, allergic rhinitis and conjunctivitis.
For inhalations from this group of medicines are used:
- Intal
- Cromohexal;
- "Ifiral."
For intranasal use, it is prescribed:
- "Ifiral";
- KromoGeksal;
- Cromoglin
- Kromosol.
As instillation into the eyes:
- "Ifiral";
- KromoGeksal;
- Cromoglin
- "Stadaglycin";
- High-chrome.
What else is on the mast cell membrane stabilizer list?
"Nedocromil sodium"
This drug as a stimulator of mast cell membranes is close in effect to sodium cromoglycate. It has a bronchodilatory and anti-inflammatory effect and is used by inhalation to prevent and treat pathologies such as bronchial asthma. When this is applied 4-8 times a day, 4 mg per 2 breaths. The maintenance dosage is equal to the therapeutic, however, the frequency of inhalation is 2 times a day. By the end of the first week of treatment, a therapeutic effect can already be observed.
Side effects may occur - cephalgia, cough, dyspepsia, bronchospasm. Mutually enhances the effects of β-adrenostimulants, glucocorticoids, ipratropium and theophylline bromide.
Lodoxamide
This pharmacological drug inhibits the release of histamines and other substances that contribute to the occurrence of allergic reactions. It is produced as eye drops. Absorbed in a small amount, the half-life takes about 8 hours. This remedy is used for allergic conjunctivitis and keratitis.
It is recommended to instill one or two drops in each eye at intervals of 6 hours. The duration of treatment is up to 1 month.
In the course of therapy with this medicine, the development of side symptoms from the organs of vision (conjunctival irritation, impaired vision, ulceration of the cornea), the sense of smell (dryness of the nasal mucosa), as well as general phenomena (dizziness, nausea, etc.).
Wearing contact lenses is contraindicated during the treatment period.
The most popular mast cell membrane stabilizer in pharmacology is Ketotifen.
Ketotifen
This medication, as well as its analogues (Airifen, Zaditen, Stafen), has a membrane-stabilizing effect, which is combined with H1-histamine-blocking. When administered orally, it is well absorbed - the bioavailability of the drug is 55%. The maximum concentration in is achieved 3-4 hours after administration, the half-life is 21 hours.
What is it used for?
This medication and its analogues are used for prophylactic purposes in case of asthma attacks, allergic rhinitis and dermatoses. It is recommended to take 1-2 mg (in the form of capsules and tablets) or 1-2 tsp. syrup 0.02% twice daily with food.
Against the background of treatment with such drugs, side symptoms may develop, for example, dry mouth, increased appetite and associated weight gain, excessive drowsiness, and inhibition of reaction rate. The drug enhances the effect of sleeping pills and sedative pharmacological agents, as well as alcohol.
Pregnancy and membrane stabilizers
The use of systemic membrane stabilizers during pregnancy is contraindicated. Topical substances - cromones - are contraindicated for use only in the first trimester and are used with caution for subsequent periods. If there are indications, for example, with allergic rhinitis and conjunctivitis of the same nature in chronic form, after 15 weeks of pregnancy it is allowed to use a solution of cromohexal 2% in the form of eye drops or a spray for nasal use - in standard dosages.
During the lactation process, the use of cromons is carried out exclusively in the presence of strict indications.
We examined the mechanism of action of mast cell membrane stabilizers.