Материал: npe

Allylamines- synthetic drugs that have a predominantly fungicidal effect. Unlike azoles, they block the earlier stages of ergosterol synthesis

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1. Types of action of medicinal substances

There are the following types of action: local and resorptive, reflex, direct and indirect, main and side, and some others.

Local actionthe drug has on contact with the tissues at the site of its application (usually the skin or mucous membranes). For example, with surface anesthesia, the local anesthetic acts on the endings of the sensory nerves only at the site of application to the mucous membrane. To provide local action, medicinal substances are prescribed in the form of ointments, lotions, rinses, patches. When prescribing certain medicinal substances in the form of eye or ear drops, they also count on their local action. However, a certain amount of the drug is usually absorbed from the site of application into the bloodstream and has a general (resorptive) effect. With local application of medicinal substances, a reflex action is also possible.

Resorptive action(from Lat. resorbeo - I absorb) - the effects caused by medicinal substances after absorption into the bloodstream or direct injection into a blood vessel and distribution in the body. With a resorptive action, as with a local one, the substance can excite sensitive receptors and cause reflex reactions.

Direct (primary) action - changes in organ functions by drugs as a result of action on the cells of these organs (cardiac glycosides increase heart contractions, blocking Na + -, K + -ATPase of myocardial muscle cells; diuretics increase urine output, disrupting the reabsorption of ions and water in the renal tubules).

Indirect (secondary) action- a change in the functions of organs and cells by drugs as a result of action on other organs and cells that are functionally related to the former (cardiac glycosides have a diuretic effect, as they increase heart contractions → improve blood flow in the kidneys → increase filtration and urine formation).

A special case of indirect action is reflex - a change in the functions of organs due to direct stimulation of sensitive nerve endings. Depolarization of nerve endings causes an impulse, which is transmitted to the executive organs along reflex arcs with the participation of nerve centers. Skin irritants have reflex effects as a result of excitation of exteroreceptors; interoreceptors - expectorant, emetic, choleretic, laxatives; vascular chemoreceptors - analeptics; skeletal muscle proprioceptors - muscle relaxants.

Reversible action due to the establishment of fragile physicochemical bonds with cytoreceptors, which is typical for most drugs.

Irreversible action arises as a result of the formation of covalent bonds with cytoreceptors, which is characteristic of a few drugs, usually highly toxic and used topically.

Main action - therapeutic effects of drugs.

Side effect - additional, undesirable effects.

The pharmacological effects of the same drug can be major or side effects in various diseases. So, in the treatment of bronchial asthma, the main effect of adrenaline is the expansion of the bronchi, with hypoglycemic coma - an increase in glycogenesis and an increase in blood glucose.

Adverse reactions are observed when taking many medicines. Their frequency in outpatient treatment reaches 10 - 20%, and 0.5 - 5% of patients require hospitalization due to complications of pharmacotherapy.

Selective action- the effect of drugs on the functions of only certain organs and systems. It is due to a greater extent to selective binding to cytoreceptors, to a lesser extent to selective accumulation in organs and tissues, although there are examples of drugs creating high concentrations in cells on which they act. Magnesium sulfate, not being absorbed from the intestines, enhances peristalsis and causes a choleretic effect. When administered parenterally, magnesium ions inhibit the central nervous system. Inhalation anesthetic drugs create a concentration in the brain that is 1.5 - 2 times higher than in the blood. Iodine intensively enters only the thyroid gland.

2. Alpha and alpha, beta adrenomimetic substances. Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.

Classification:

1. Stimulating alpha and beta-adrenergic receptors: ADRENALINE HYDROCHLORIDE (beta 1,2, alpha 1,2) NORADRENALINE HYDROTARTRAT (alpha 1,2, beta1)

2. Stimulating predominantly alpha-adrenergic receptors: MESATON (alpha1), NAFTHISIN, GALAZOLINE (alpha2)

3. Stimulating predominantly beta-adrenergic receptors: ISADRIN (1,2). SALBUTAMOL, PHENOTHEROL (2). DOBUTAMINE (1)

ADRENALIN - belongs to the group of phenylalkylamines, is a biogenic catecholamine.

Main pharmacological effects:

CNS - increases excitability, improves cerebral circulation, stimulates the secretion of adrenorcorticotropic hormone (ACTH) by the adenohypophysis

EYE- dilates the pupil due to contraction of the radial muscle of the iris, practically does not affect accommodation (since there are no adrenergic receptors in the ciliary muscle). It complicates the outflow of intraocular fluid, but reduces its production (inflow) due to the narrowing of the retinal vessels. The latter effect is predominant; therefore, intraocular pressure as a whole is somewhat reduced. This makes it possible to use the drug in the open-angle form of glaucoma (associated with excessive production of intraocular fluid), but in the closed-angle form (associated with a deterioration in outflow), adrenaline is contraindicated

SPLEEN - reduces the capsule and trabeculae, which leads to the release of deposited erythrocytes and platelets into the blood.

BRONCHI - expands

A HEART - increases the strength of heart contractions, conduction, excitability, automatism, increases stroke and minute blood volumes. It mainly causes tachycardia, which, however, can be replaced by bradycardia. The latter is associated with the emergence of vagal reflexes from vascular baroreceptors (aortic arch, carotid sinus zone) in response to an increase in the stroke volume of blood...

Activates metabolic processes in the myocardium. Improves blood supply to the myocardium (due to the expansion of the coronary vessels)

Epinephrine is effective when administered locally and parenterally (subcutaneous, intravenous, intramuscular). Duration of action - from 5 to 30 minutes

MEZATON - It causes a vasoconstrictor effect and increases blood pressure weaker than adrenaline and norepinephrine, but for a longer period (intravenously - up to 20 minutes, subcutaneously - 40-50 minutes). This is due to the fact that mezaton is a synthetic preparation, it is not a catecholamine, therefore it is not destroyed by the COMT enzyme. Effective when taken orally. It can be used in conditions of cyclopropane and fluorothane anesthesia. From the heart causes bradycardia (reflex)

3. Antihistamines (H1-histamine receptor blockers). Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.

Antihistaminesdrugs- a group of drugs that competitively block histamine receptors in the body, which leads to inhibition of the effects mediated by them.

H1-histamine receptor blockers:

prevent the interaction of histamine with specific receptors and eliminate the main clinical manifestations of an immediate allergic reaction: edema, hyperemia, itching, spasm of gl / m of internal organs, vasodilation, hypersecretion.

Classification:

Derivatives

1. Diphenylmethane - DIMEDROL, TAVEGIL

2. Phenothiazine - DIPRAZINE

3. Piperazine - STUGERON

4. Ethylenediamide - SUPRASTIN

5. Carboline - DIAZOLINE

Different chemical structure: ZIRTEK (cyterizin), ALLERGODIL, KESTIN

Features of 1st generation H1 blockers:

- They penetrate the BBB well, therefore they have a pronounced sedative effect (drowsiness, lethargy, lethargy, decreased performance)

-Low affinity for H1-receptors in therapeutic doses

-Insufficient duration of action (4-6 hours)

H-high selectivity in relation to H1-receptors (they also block M-cholinergic receptors, serotonin 5HT receptors,-adrenergic receptors, dopamine receptors)

-Appetite stimulation and weight gain

-Dysfunction of the gastrointestinal tract

- Often addictive

four. Antihelminthic drugs. Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.

Anthelminthic agents disrupt the function of the neuromuscular system of helminths, exhibiting anticholinesterase (emetine), cholinomimetic (ditrazine, combantrine) or anticholinergic (piperazine) action. Many drugs (levamisole and others) disrupt various types of metabolism in helminths

The effectiveness of antihelminthic agents for various helminthiasis is not the same and is primarily determined by the biological species of parasitic worms and their localization in the body. On the basis of ideas about the direction of action of drugs on various classes of helminths, a classification of antihelminthic agents is constructed. In accordance with this, funds are allocated that are used mainly for the treatment of nematodes, cestedoses and trematodes.

Anthelminthic agents used mainly for nematodes

Anthelminthic drugs used mainly for cestodosis