Poisoning can be accidental, deliberate and associated with the characteristics of the profession. Most often - poisoning with ethyl alcohol, sleeping pills, psychotropic, narcotic and non-narcotic analgesics, insecticides. The main task is to remove from the org-ma the substance that caused the intoxication. Detoxification principles: • delay absorption (gastric and intestinal lavage, adsorbents, laxatives, with parenteral administration - inject with adrenaline (vasoconstriction), ice pack, tourniquet); • to accelerate its withdrawal from the orgma - forced diuresis, peritoneal dialysis, hemodialysis, hemosorption, blood replacement, plasmapheresis, lymphodialysis, pulmonary hyperventilation, artificial respiration; • neutralize with antidotes. Antidotes: cause deionization of the poison, compete with biochemical structures for the capture of poison, compete with the poison for the capture of biochemical structures;
Alpha-adrenergic blockers are substances that block alpha-adrenergic receptors and prevent their connection with catecholamines. Classification: I. Blocking alpha-adrenergic receptors:
1) Non-selective: fasting and presynaptic
-Phentolamine (alpha1, alpha2)
-Tropafen (alpha1, alpha2)
Nicergoline, pyrroxane, dihydroergotomin
2) Selective: postsynoptic
-Prazosin (alpha1), doxazosin, urapidil
Mechanism of action: block adrenergic receptors, disrupting interaction with mediators.
Main effects: vasodilation of the skin, mucous membranes, celiac vessels, ↓ blood pressure, improved tissue nutrition. Indications: hypertensive crises, migraines, peripheral vascular spasms, Raynaud's disease, leg ulcers, diagnosis and treatment of pheochromocytoma, peripheral circulation disorders, ischemic cerebral circulation, sympathoadrenal and diencephalic crises, neurodermatitis, withdrawal symptoms. Side effects: tachycardia, nausea, diarrhea, collapse, dizziness, vomiting. Contraindications: organic diseases of the heart and blood vessels, pregnancy, childhood, hypotension, impaired liver and kidney function.
Phentolamine - enhances gastrointestinal motility, increased secretion of gastric juice, quickly becomes addictive, acts for 10-15 minutes, improves the blood supply to organs, especially the skin, expands the pulmonary circulation, weakly absorbed from the gastrointestinal tract.
Tropafen - acts for a long time, lowers blood pressure, causes a slight tachycardia.
Prazosin is 10 times more active than phentolamine, does not affect heart rate, the duration of action is 6-8 hours.
Classification:
1) Diphenylalkylamines - verapamil, halopamil.
2) Benzothiazepines-diltiazem, clentiazem
3) Dihydropyridines-phenigidine, nifedipine, amlodipine, nislodipine, lerkamen
Mechanism of action: disrupt the entry of calcium into the muscle cells of the heart and blood vessels through slow calcium channels. They reduce the work of the heart, dilate the coronary vessels, reduce the need for and increase the delivery of oxygen.
Side effects: lowering blood pressure, increased heart failure, vomiting, dizziness, allergies.
Contraindications: arrhythmias caused by glycosidic intoxication.
Phenigidine - causes a pronounced expansion of the coronary vessels, lowers blood pressure, has a weak antiarrhythmic effect, the effect develops after 20 minutes for 6-8 hours.
Verapamil - reduces the flow of calcium into the cell, reduces potassium in the cell. The effect of coronary expansion, reduces the activity of the myocardium, blood pressure, oxygen consumption, reduces venous tone and platelet aggregation, increases urine output. The action develops after 2 hours.
one). Types of drug therapy. The dependence of the action of pharmacological agents on the initial state of the organism (the influence of age, sex, genetic factors, circadian rhythms and pathological background).
Medicines are prescribed for various purposes. Concerning
they can be divided into 4 main groups, depending on the type of therapy:
· Etiotropic (causal) therapy - elimination of the cause of the disease: the use of antimicrobial, antiviral and antiparasitic agents for infectious diseases, antidotes for poisoning.
· Pathogenetic therapy - the effect on the pathogenetic mechanisms of diseases: the appointment of antihypertensive drugs for arterial hypertension, cardiac glycosides for heart failure, anti-inflammatory drugs for rheumatic diseases, psychotropic drugs for the treatment of mental disorders.
· Symptomatic therapy - elimination or reduction of individual manifestations of the disease: the use of painkillers and antipyretic drugs.
· Substitution therapy - replenishment of an insufficient amount of natural metabolites of the body: the use of vitamin, hormonal, enzyme agents, salts of iodine, fluorine, iron, calcium. For prophylactic purposes, antiseptics, disinfectants, antiviral, vitamin agents are prescribed
Floor.Animal experiments and clinical studies indicate certain sex differences in drug metabolism and sensitivity to certain pharmacological effects. So, due to the fact that male sex hormones stimulate the synthesis of microsomal liver enzymes, the elimination of certain medicinal substances (paracetamol, verapamil, benzodiazepines, propranolol) occurs faster in men. The existing sex differences in ethanol metabolism are associated with the high activity of alcohol dehydrogenase in men. There is clinical evidence that women are more sensitive to the action of certain drugs.
Age. Age-related changes in drug action are especially evident in newborns and patients over 60 years of age.
Newborns are more sensitive to drugs. In terms of the rate of absorption, distribution, metabolism and excretion of substances, they differ significantly from adults. This is mainly due to the imperfection of the metabolism of medicinal substances (due to the lack of enzymes), reduced renal function, increased permeability of the blood-brain barrier, underdevelopment of the endocrine, nervous and other systems of the body. In old and senile age, pharamacokinetic processes are slow. The change in the rate of absorption is mainly associated with a decrease in the acidity of gastric juice, a decrease in blood flow in the intestine, inhibition of active absorption systems, etc. The distribution of drugs in the elderly may change due to changes in binding to blood plasma proteins, decrease in blood flow in organs and tissues. A decrease in the metabolism of medicinal substances with age is associated with a decrease in the activity of liver enzymes and a decrease in hepatic blood flow. Decreased renal function leads to a slower elimination of drugs. Therefore, for patients over 60 years of age, the doses of substances that depress the central nervous system (hypnotics, drugs of the morphine group), cardiac glycosides, diuretics should be reduced by ½, and the doses of other potent and toxic substances should be reduced to ⅔ of the doses recommended for middle-aged people. Geriatric pharmacology is engaged in the study of the features of the action and use of drugs in elderly and senile people. Decreased renal function leads to a slower elimination of drugs. Therefore, for patients over 60 years of age, the doses of substances that depress the central nervous system (hypnotics, drugs of the morphine group), cardiac glycosides, diuretics should be reduced by ½, and the doses of other potent and poisonous substances should be reduced to ⅔ of the doses recommended for middle-aged people. Geriatric pharmacology is studying the features of the action and use of drugs in elderly and senile people. Decreased renal function leads to a slower elimination of drugs. Therefore, for patients over 60 years of age, the doses of substances that depress the central nervous system (hypnotics, drugs of the morphine group), cardiac glycosides, diuretics should be reduced by ½, and the doses of other potent and poisonous substances should be reduced to ⅔ of the doses recommended for middle-aged people. Geriatric pharmacology is engaged in the study of the features of the action and use of drugs in elderly and senile people.
Diltiazem - the action develops after 30 minutes.
4. Antibiotics of the penicillin group. Classification. Mechanism of action. Action character. Spetr of action. Indications for use. Side effects. Contraindications Indications. Comparative evaluation of drugs.
Classification: Natural (biosynthetic)
Parenteral: short-acting (3-4 hours) benzylpenicillin sodium salt
long-acting (depot-penicillin): benzylpenicillin novocaine salt, bicillin 1.5
Oral: phenoxymethylpenicillin
Semi-synthetic: a) resistant to penicillase: oxacillin, nafcillin, cloxocillin.
b) Broad spectrum of action: ampicillin, amoxicillin
c) A broad spectrum of action with antipseudomonal activity: carbenicillin
d) Inhibitor-protected: amoxiclav, trifamox, tazocin, tymentin.
e) Combined: ampiox.
Mechanism: inhibit the synthesis of cell wall components, prevent the formation of peptide bonds.
Mode of action: bactericidal, affect only dividing cells.
Spectrum e: gram (+) predominantly staphylococci, streptococci, meningococci, gonococci, spirochetes, clostridia, causative agents of diphtheria, anthrax, listeria.
Indications: upper respiratory tract infections (scarlet fever), erysipelas, rheumatism, pneumonia, meningitis, endocarditis, syphilis, leptosporosis, anaerobic infections.
Side effects: allergies, dysbiosis, glossitis, stomatitis, dyspepsia.
Contraindications: individual intolerance, allergies.
Benzylpenicillins act briefly (3-4 hours), bicillin - long-term (once every 7-14 days, months). Oxacillin is resistant to penicillinase, it is destroyed in an acidic environment. Nafcillin penetrates the BBB. Ampicillin is destroyed by penicillinase, acid-resistant. Carbenicillin is destroyed in an acidic environment and by penicillinase.
Benzylpenicillin is widely used in pediatrics because low toxicity, it can be administered in large doses. Not effective when taken by mouth, even in young children with low gastric acidity. Penicillin is a GABA antagonist and can cause seizures when given in large doses. The younger the child, the greater the risk of developing seizures. Ampicillin, when administered orally, causes diarrhea in a third of children. Oxacillin is capable of impairing liver function.
The state of the body.Various pathological conditions can cause changes in the pharmacokinetics and pharmacodynamics of drugs. In diseases of the gastrointestinal tract, there may be a decrease in the rate and degree of drug absorption. Some diseases of the lungs and cardiovascular system lead to significant changes in hemodynamics, which affects the distribution of medicinal substances.
In case of impaired renal function, the effect of substances excreted by the kidneys in an unchanged form is lengthened.
In the focus of inflammation, the effect of local anesthetics is sharply weakened, and the effect of sulfonamides is reduced in purulent wounds.
With extreme caution, medications should be prescribed to pregnant and lactating women. It is necessary to take into account not only the altered sensitivity of the body, but also the possibility of penetration of medicinal substances through the placental barrier, its excretion in milk and the harmful effect on the fetus and child.
Genetic factors.There are significant differences in the individual sensitivity of people to drugs, determined by genetic factors. The section of pharmacology Pharmacogenetics studies the role of genetic factors in changing the action of drugs. Very often, individual differences in the action of drugs are due to differences in their metabolism. This happens due to a change in the activity of enzymes that metabolize drugs, which is often associated with a mutation of genes that control the synthesis of these enzymes. Violation of the structure and function of the enzyme is called enzymopathy (fermentopathy). With enzymopathies, the activity of the enzyme can be increased (the metabolism of drugs is accelerated and their action is weakened) or decreased (the metabolism slows down, which can lead to an increase in the action of the drug and the appearance of toxic effects). With a genetic deficiency of some enzymes, atypical reactions to substances (idiosyncrasy) may occur. A typical example of idiosyncrasy is the hemolytic effect of some antimalarial drugs (quinine, primaquine, chloroquine) in congenital insufficiency of glucose-6-phosphate dehydrogenase in erythrocytes. As a result of a deficiency of this enzyme, quinone is formed, which causes hemolysis of erythrocytes.
2). M-anticholinergic substances. Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs. Atropine poisoning, measures of assistance.
M-anticholinergics (atropine-like drugs)
Plant origin:
- Atropine (alkaloid of plants of the Solanaceae family - belladonna, dope);
- Scopolamine (henbane alkaloid, dope, mandrake);
- Platyphylline (rhomboid alkaloid):
Synthetic:
- Metacin;
- Ipratropium bromide (aerosol "Atrovent", "Itrop");
- Troventol;
- Pirenzepine (Gastrozem, Gastrocepin).
INDICATIONS FOR USE OF M-CHOLINO BLOCKERS
ATROPINE
1. With spasms of smooth muscle organs [colic (intestinal, renal, hepatic, pancreatic, etc.), bronchospasm].
2. In the treatment of gastric ulcer and 12 duodenal ulcer, acute pancreatitis.
3. To eliminate hypersalivation (parkinsonism, poisoning with salts of heavy metals).
4. For premedication before surgery (suppresses the secretion of the eye, salivary, nasopharyngeal, tracheobronchial glands).
5. With an atrioventricular block of vagal origin.
6. Sometimes with angina pectoris.
7. In ophthalmology for diagnostic purposes (retinal examination, selection of glasses), in the treatment of iridocyclitis.
8. In the treatment of poisoning by direct and indirect (anticholinesterase agents) m-cholinomimetics.
SCOPOLAMIN
1. For the same indications as atropine.
2. For the prevention of sea and airborne diseases (contained in the table. "Aeron"), with parkinsonism.
PLATIFILLINE
1. With spasms of the stomach, intestines, bile ducts, gall bladder, ureters.
2. To reduce the pathologically increased tone of the cerebral and coronary vessels.
3. For short-term pupil dilation.
CONTRAINDICATIONS TO APPOINTMENT
M-CHOLINOBLOCKERS
Glaucoma, organic lesions of the heart and blood vessels, prostatic hypertrophy, kidney disease.
Prescribe cautiously to persons of the elderly and senile age (there may be poisoning).
SIDE EFFECTS
Dry mouth, dry skin, scarlet fever, dysphagia (impaired swallowing), thirst, visual impairment (due to accommodation paralysis).
Mechanism of action- the formation of a complex with the M-cholinergic receptor, which prevents the interaction of the receptor with acetylcholine. By blocking M-cholinergic receptors, this group of drugs removes the effects of excitation of the parasympathetic nervous system (acetylcholine), and sympathetic influences begin to prevail.