2. Allergy is the hypersensitivity of the
organism to exogenous substances
possessing antigenic properties (antigens).
When the antigens act on the body, the
humoral immunity system is activated and
antibodies of the E class are formed, which
are fixed on the mast cells.
When re-entering the body, the antigen
interacts with the antibodies. This leads to
the degranulation of mast cells, the isolation
of allergic mediators (histamine, etc.) and the
development of allergic reactions.
3. ALLERGIC REACTIONS ARE OF TWO TYPES:
The immediate action hypersensitivity reaction (IAHR) develops very
quickly - a few minutes after the sensitized organism enters the allergen
and lasts for hours. The mechanism of their development is associated
with the reaction of humoral immunity (anaphylactic shock, pollinosis,
Quincke's edema, urticaria).
Hypersensitivity reactions of delayed type (HRDT) develop after 8-12
hours and last for several days and even weeks. They are
characterized by tissue reactions and are associated with the response
of cellular immunity (autoimmune reactions, eczema, contact dermatitis,
transplant rejection reaction, etc.)
4. CLASSIFICATION OF ANTI-ALLERGIC REMEDIES
Remedies used in the IAHR
1. Remedies that prevent the release of histamine and other BAS
from mast cells and basophils.
а) Glucocorticoids: prednisolone, dexamethasone, etc.
б) Adrenomimetics: epinephrine, isadrine, salbutamol, and others.
в)M-holinoblokatory: atropine, atrovent.
г) Inhibitors of degranulation of mast cells: cromoglycic acid (intal),
ketotifen, nedocromil.
2. Inhibitors of the interaction of histamine with tissue receptors
(antihistamines that block N1 receptors): dimedrol, diprazine,
diazolin, tavegil, suprastin, astemizole.
II Remedies used in the HRDT
а) Glucocorticoids: prednisolone, dexamethasone.
б) Cytotoxic drugs: methotrexate, cyclophosphamide, azathioprine.
5. ADRENOMIMETICS
Epinephrine (adrenaline) - is used to stop anaphylactic
shock (a deadly allergic reaction, which is accompanied
by a drop in blood pressure, bronospasms, swelling of
the larynx).
Ephedrine (sympathomimetic) can also be used for
anaphylactic shock in injection. The effect occurs more
slowly (30-40 min.), But more prolonged. In tablets,
ephedrine is used to stop lung attacks of bronchial
asthma.
For relief of allergic bronchospasm, β2-adrenomimetics-
salbutamol, terbutaline, fenoterol, are inhaled.
Selective β2-adrenomimetics with prolonged action:
formoterol, biholterol, salmeterol. They are used to
prevent nighttime attacks of bronchial asthma.
6. REMEDIES THAT PREVENT THE DEGRANULATION
OF MAST CELLS
(MEMBRANE STABILIZERS)
Mechanism of action: degranulation inhibitors have a
pronounced membrane-stabilizing effect on mast cells,
thereby limiting the process of their degranulation. The
mechanism of action is based on blockade by these
remedies of chlorine channels of membranes. Transport of
chlorine into the cytoplasm of cells causes hyperpolarization
of the membrane, necessary for calcium intake. Preventing
calcium intake in the cytoplasm of mast cells, these drugs
prevent the release of them mediators of allergy: histamine,
leukotrienes, cationic proteins
7. Cromoglycic acid (intal) is used to prevent
attacks of allergic bronchial asthma.
However, the effect develops very slowly and
the pronounced bronchodilator effect occurs
only after 2-4 weeks of continuous
administration of the drug.
Ketotifen (zaditen) - one of the best drugs for
the treatment of atopic bronchial asthma. Along
with the membrane-stabilizing action has
antihistamine effect. Can be used in children's
practice.
Nedocromil (tayled) has bronchodilating and
anti-inflammatory effects. Therefore, it is used
for bronchial asthma not only atopic genesis,
but also for other etiology.
8. ANTIHISTAMINES THAT BLOCK H1 RECEPTORS
Histamine is a biogenic substance that takes
part in the development of allergies,
inflammations; Stimulates the secretion of
hydrochloric acid in the stomach. Histamine
dilates the blood vessels, increases their
permeability, lowers blood pressure, increases
the tone of the bronchial tubes. These effects
are associated mainly with the excitation of
histamine h1 receptors.
Medicine remedies that block h1 -receptors are
used for allergic reactions - urticaria, skin
itching, allergic conjunctivitis, angioedema,
edema of Quincke, vasomotor rhinitis, etc. h1 -
receptor blockers penetrating into the central
nervous system have a sedative effect.
9. Classification of antihistamines
The first generation: diphenhydramine (dimedrol),
clemastine (tavegil), promethazine (diprazine),
chloropyramine (suprastin).
The second generation: astemizole, terfenadine.
The third generation: azelastine, loratadine (klaritin).
10. Diphenhydramine (dimedrol) blocks central and peripheral
N1 receptors; Effectively weakens allergic reactions.
Operates 4-6 hours In connection with the blockade of
central N1-receptors has a sedative, hypnotic effect,
reduces the excitability of the central links of the vestibular
apparatus.
Indications for use: Urticaria, itching, pollinosis,
angioedema, insect bites, drug allergy, serum sickness.
Applied as a hypnotic, as well as for the prevention of
motion sickness (sea and air sickness).
Adverse events: short-term numbness, dryness of the oral
mucosa, drowsiness, weakness, decreased performance,
nausea. In children, large doses of diphenhydramine
cause motor and mental arousal, insomnia, seizures.
11. Chloropyramine (suprastin) in addition to anti-
allergic properties, has M-holinoblokiruyuschimi,
spasmolytic properties. Has a moderate oppressive
effect on the CNS. The duration of action is 4-6
hours.
Due to the fact that sedative and soporifc effects of
these drugs are not always desirable,
antihistamines of the second generation -
astemizole, terfenadine, and then - the third
generation - azelastine, loratadine (claritin) were
synthesized. Unlike antihistamines of the first
generation, these drugs practically do not inhibit the
central nervous system and are characterized by a
longer antiallergic effect. So, astemizol and
loratadine are prescribed once a day.
12. ГЛЮКОКОРТИКОИДЫ (ПРЕДНИЗОЛОН, ДЕКСАМЕТАЗОН, ФЛУКОРТОЛОН)
Glucocorticoids (HA) have anti-inflammatory and
immunosuppressive properties. Inhibit the production of
antibodies. In addition, glucocorticoids prevent the
degranulation of mast cells.
HA cause both absolute and relative T-lymphocytopenia, inhibit
the graft rejection reaction, inhibit the activity of phagocytes,
increase the sensitivity of adrenoreceptors to
catecholamines.
GC is used mainly for severe and moderate manifestations of
allergies (anaphylactic shock, Quincke's edema, serum
sickness, etc.). In dermatological practice, it is used for
allergic skin lesions.
Glucocorticoids are used as immunosuppressants for
autoimmune diseases (rheumatoid arthritis, systemic lupus
erythematosus, dermatomyositis, Bechterew's disease,
eczema), as well as as auxiliary agents for organ and tissue
transplantation.
13. ЦИТОСТАТИКИ – СРЕДСТВА, УГНЕТАЮЩИЕ РОСТ И ДЕЛЕНИЕ КЛЕТОК
Cytostatics are particularly effective in suppressing the division of
rapidly dividing cells: bone marrow cells, gastrointestinal epithelium,
gonadal gland cells, tumor cells. Cytostatics are used mainly for
tumor diseases, and some as immunosuppressants.
Cyclophosphamide (cyclophosphane) inhibits lymphoid and myeloid
hematopoiesis. The proliferation of B- and T-lymphocytes and their
precursors is suppressed. It is used for autoimmune diseases
(rheumatoid arthritis, systemic lupus erythematosus, etc.).
Due to the suppression of cellular immunity, cyclophosphamide
effectively prevents the transplant rejection reaction during organ and
tissue transplantation.
Cyclophosphamide is used as an antitumor agent for lung cancer,
breast cancer, lymphogranulomatosis, lymphocytic leukemia
Side effects of cyclophosphamide: bone marrow depression
(leukopenia, anemia, thrombocytopenia), interstitial pulmonary
fibrosis, hemorrhagic cystitis, amenorrhea, azoospermia, nausea,
vomiting, alopecia.
14. Azathioprine interferes with DNA synthesis. Under the action of
azathioprine, cellular immunity is suppressed to a greater extent than
humoral immunity. In addition to immunosuppressive properties,
azathioprine has anti-inflammatory properties.
It is used for autoimmune diseases (rheumatoid arthritis, systemic lupus
erythematosus, dermatomyositis, myasthenia gravis).
Side effects of azathioprine: leukopenia, thrombocytopenia, decreased
resistance to infections, dyspepsia, liver dysfunction, skin rashes.
Methotrexate interferes with folic acid metabolism (inhibits dihydrofolate
reductase) and disrupts the formation of purine and pyrimidine bases
and, accordingly, DNA synthesis.
It has immunosuppressive, anti-inflammatory and anti-inflammatory
properties.
It is used for rheumatoid arthritis and tumor diseases.
