Class III - substances that cause a uniform lengthening of the repolarization phases and the action potential.
AMIODARON5 (cordaron)
SOTALOL5 (sotakor, sotalex)
BRETILIA TOSILATE (Ornid)
NIBENTAN
IBUTILID
DOPETHYLIDE
DRONEDARON
Mechanism of action:They block β-adrenergic receptors of the myocardium, and the degree of blockade depends on the state of the tone of the ANS, it can be increased with the predominance of the tone of the sympathetic part of the nervous system. As you know, catecholamines have an arrhythmogenic effect by stimulating the β1-adrenergic receptors of the myocardium, β-blockers protect it from the arrhythmogenic effect of excess catecholamines with hyperfunction of the sympathetic division of the ANS.
Also β-blockers exhibit a direct membrane-stabilizing effect, blocking Na channels in concentrations exceeding the therapeutic one.
- treatment of atrial fibrillation and atrial flutter;
- relief and prevention of supraventricular tachycardia;
- treatment of arrhythmias in patients with mitral valve prolapse and hypertrophic cardiomyopathy;
- treatment of ventricular and supraventricular arrhythmias in patients with coronary artery disease;
- treatment of catechol-dependent ventricular tachycardia.
Side effects: - bronchospasm; - violation of peripheral circulation; - fatigue;
- in patients with diabetes - hyperglycemia; - gastrointestinal disorders; - rash, fever, "withdrawal syndrome".
Contraindications: - severe broncho-obstructive syndrome (bronchial asthma, asthmatic bronchitis); - violations of peripheral circulation (Raynaud's disease, obliterating endarteritis); - diabetes.
Amiodarone - the action develops slowly, also blocks sodium channels in the heart, noncompetitively blocks beta-adrenergic receptors and calcium channels, reduces myocardial oxygen demand, lowers heart rate, lowers blood pressure, improves coronary circulation.
Ornid - moderately lowers blood pressure.
Classification: Organic:
- (brilliant green, ethacridine lactate, methylene blue),
-detergents (chlorhexidine, cerigel, roccal).
Inorganic: - oxidizing agents (hydrogen peroxide, potassium permanganate),
acids and alkalis (boric, salicylic, benzoic acids, ammonia solution, sodium bicarbonate, sodium tetraborate, calcium hydroxide).
Dyes - antiseptic effect, antidote for cyanide poisoning; externally for the treatment of wounds.
Detergents - cationic soaps, washing and antiseptic properties, for hand treatment, sterilization of instruments.
Chlorhexidine - antiseptic, bactericidal and fungicidal action. For the treatment of wounds, hands, sterilization. For dermatitis and allergies, do not use.
Oxidants: hydrogen peroxide - releases O2 and forms foam, mechanical cleaning of the wound occurs; antiseptic and deodorizing effect.
Potassium permanganate - in the presence of organic substances, it removes O2, manganese oxide is formed; antimicrobial, deodorizing, astringent action. For the treatment of wounds, gastric lavage.
Acids are antiseptic, fungicidal, irritating, distracting. Outwardly.
Sodium bicarbonate - antacid, anti-inflammatory; for rinsing, rinsing.
Na tetraborate - antiseptic, topical.
Ammonia solution (ammonia) - for hand treatment, inhalation to stimulate breathing.
Sechenov - pharmacology of neurotropic drugs. In 1866, "Reflexes of the head of the brain."
Pavlov - the founder of psychopharmacology, began his activity in the field of pharmacology in the clinic of S.P. Botkin, where he headed the experimental laboratory for 11 years. There, under the leadership of Pavlov, cardiac glycosides, antipyretics, and a number of ions were studied. For the first time in the history of science, Pavlov and his colleagues studied the effect of substances (bromides, caffeine) on higher nervous activity in healthy animals and in experimentally induced neuroses. Pavlov also studied the effects of various substances - acids, alkalis, ethyl alcohol, bitterness - on digestion.
Botkin - studied cardiotropic drugs. In 1860 he founded a clinical experimental laboratory, where the first Russian studies on clinical pharmacology and a therapy experiment were carried out.
Pirogov - research of drugs for anesthesia. The first operation under anesthesia in 1847 on the battlefield.
Beta-adrenergic agonists are biological or synthetic substances that stimulate beta-adrenergic receptors and have a significant effect on the basic functions of the body.
Classification:
I. Stimulating predominantly Beta1-adrenergic receptors:
Dobutamine
Beta2-adrenergic receptors:
-Salbutamol
-Terbutaline (bricanil)
-Phenoterol (Berotec, Partusisten)
-Salmeterol (Servent)
-Formoterol
Beta1 Beta2-adrenergic receptors:
-Izadrin
Beta2 Beta1-adrenergic receptors:
-Orciprenaline (Alupent, Asthmopent)
Izadrin - Stimulation of Beta1 receptors: increased strength and heart rate, improved atrioventricular conduction, systolic blood pressure increases, diastolic blood pressure decreases, mean blood pressure decreases.
At the same time, the need for oxygen in the heart sharply increases; it cannot be used parenterally in order to avoid the development of microinfarctions.
Stimulation of β2-receptors leads to a decrease in the tone of the bronchi, blood vessels, uterus.
Indications for use:
- atriventricular block (sublingual tablets);
- bronchial asthma, pulmonary emphysema.
- to facilitate bronchoscopy and bronchography.
Side effects: tachycardia, arrhythmias, nausea, hand tremors.
Contraindications: ischemic heart disease, hypertension, severe atherosclerosis, hyperthyroidism, diabetes mellitus.
Salbutamol - dilates the bronchi, there is no tachycardia, blood pressure does not change, the effect on the heart is insignificant. The main therapeutic effects are bronchodilatory and tocolytic (relax the uterus).
Terbutaline is a drug of medium duration of action (up to 4 - 6 hours). Available in aerosol, tablet and ampoule form. They are used for broncho-obstructive diseases, with the threat of termination of pregnancy due to increased uterine tone.
Vomiting is a complex reflex act that is controlled by the corresponding center of the medulla oblongata.
Classification of emetics:
1) central action (on dopamine receptors trigger zone) - apomorphine hydrochloride,
2) reflex action - thermopsis and ipecacuanha,
3) peripheral action - copper sulfate and zinc sulfate.
Apomorphine is mainly used.
Apomorphine - stimulates dopamine trigger-zone receptors. Used for acute poisoning, treatment of alcoholism. Side effects - collapse, visual hallucinations, neurological disorders. Contraindications: burns of the stomach with acids and alkalis, peptic ulcer, lung disease with possible bleeding, heart disease.
Antiemetic classification:
1) dopamine receptor blockers (inhibit the trigger zone) - a derivative
benzamide (metoclopramide), Phenothiazine derivatives (thiethylperazine, ethaperazine, chlorpromazine, triftazine) Butyrophenone derivatives (haloperidol)
2) blockers of M-cholinergic receptors - "Aeron", scopolamine,
3) blockers of histamine H1 receptors - diprazine, diphenhydramine,
4) blockers of serotonin receptors in the central nervous system and in the periphery - ondansetron, tropisetron.
1) phenothiazine derivatives: chlorpromazine, triftazine, ethaperazine, fluorophenazine, thiethylperazine (torecan). Thiethylperazine (torecan) is considered the best due to its strong selective effect. There is evidence that in addition to the block of dopamine receptors of the trigger zone, thiethylperazine has a depressing effect directly on the vomiting center. The drug is well tolerated.
2) butyrophenone derivatives (haloperidol).
1) and 2) groups are effective in vomiting caused by substances whose action is directed to the trigger zone (digitalis glycosides, apomorphine, etc.). They also eliminate vomiting that occurs in the postoperative period, with radiation sickness, toxicosis of pregnant women.
When motion sickness drugs of these groups are ineffective.
Side effects are possible: dry mouth, drowsiness, tachycardia, hypotension, with prolonged use - parkinsonism.
3) benzamide derivative - metoclopramide (raglan, cerucal), the central effects of which, including antiemetic, are associated with the fact that it blocks dopamine D2 receptors, and in high doses, serotonin 5-HT4 receptors.
The drug has an antiemetic and antiemetic effect. In addition, it regulates the function of the gastrointestinal tract, normalizes tone and motility, and is effective for vomiting of any genesis, with the exception of motion sickness and diseases of the inner ear. Unlike manuf. phenothiazine, which have an M-anticholinergic effect, metoclopramide is a strong parasympathomimetic and therefore it helps to accelerate the evacuation of stomach contents.
As an antiemetic, metoclopramide is indicated for vomiting and nausea:
- associated with irritation of the gastrointestinal mucosa;
- with radiation sickness;
- uremia;
- intoxication with cardiac glycosides;
- for the prevention of side effects of cytostatics and antiblastoma antibiotics;
- diet disorders;
- complex therapy of peptic ulcer disease, patients with gastritis;
- dyskinesia of the abdominal organs, flatulence;
- vomiting of pregnant women;
Side effects: in rare cases, parkinsonism may occur (caffeine must be administered), as well as drowsiness, tinnitus, dry mouth.
An antagonist of dopamine D2 receptors is also an antiemetic agent, domperidone (motilium), which is structurally similar to the group of butyrophenone preparations (droperidol), and is similar in action to metoclopramide. The drug does not cross the blood-brain barrier (unlike metoclopramide) and does not cause extrapyramidal disorders. It is used as an antiemetic and prokinetic agent.
Domperidone is indicated for functional disorders of the gastrointestinal tract, gastric hypotension, reflux esophagitis. The drug softens biliary dyskinesia.
Side effects: increased prolactin levels, headache, dry mouth, dizziness.
4. Blockers of serotonin 5-HT3-receptors - tropisetron (novoban), ondansetron (emetron).
They block the serotonin 5-HT3 receptor in the chemoreceptor trigger zone and in the gastrointestinal tract and are indicated for the prevention or elimination of vomiting during chemotherapy of tumors and radiation sickness.
Side effects: dyspepsia, dizziness, constipation, increased blood pressure.
4. Means used in the treatment of protozoal infections (amebiosis, leishmaniasis, giardiasis, trichomonadosis, balantidiasis). Classification. Mechanism of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.
Amoebiasis: at any localization (metronidazole); in the intestinal lumen (quiniofon); in the lumen and wall of the intestine (tetracycline); in the wall of the intestine and liver (emetine); in the liver (hingamin).
Mechanism:amoebicidal, tetracycline inhibits intestinal flora and this inhibits the growth and reproduction of amoebas (indirect division). A side effect is diarrhea, emetine accumulates (damage to the CVS, gastrointestinal tract, nervous system, kidneys and liver). It is impossible for diseases of the heart and kidneys. Combinations of drugs are used: metronidazole + quiniofon.
Leishmaniasis: for visceral and skin (solusurmin), for skin (monomycin, metronidazole), topically (akrikhin).
Mechanism:bactericidal. Side effects - nausea, headache, rash, inhibition of hematopoiesis, ↓ blood pressure. In case of an overdose of solusurmin - unitiol. Contraindications: acute infectious diseases, intoxication, organ damage to internal organs. Monomycin oto- and nephrotoxicity. Akrikhin is not allowed for mental illness.
Giardiasis:metronidazole, aminoquinol, furazolidone. Mechanism: ↓ activity of enzyme systems, disruption of protein and nucleic acid synthesis. Side effects - dyspepsia, headache, allergies, inhibition of hematopoiesis. Contraindications: violation of hematopoiesis, diseases of the central nervous system.
Trichomoniasis: metronidazole, tinidazole, trichomonacid, nitazole. Mechanism: bactericidal action. Side effects - dyspepsia, tremors. Contraindications: pregnancy in the 1st trimester, lactation, hematopoiesis disorder, central nervous system diseases. Tinidazole is more active than metronidazole.
Toxoplasmosis:chloridine, sulfonamides, pentamidine. Mechanism: bacteriostatic (chloridine inhibits the transition of dihydrofolic acid to tetrahydrofolic acid). Side effects - teratogenic effects, anemia, leukopenia. Contraindications: pregnancy, blood and kidney diseases.
Balantidiasis: monomycin, tetracycline, quiniophone.
With the combined use of medicinal substances, their effect can be enhanced (synergism) or weakened (antagonism)
Synergy - unidirectional action of two or more medicinal substances in which a pharmacological effect develops that exceeds the effects of each substance separately. Synergy occurs in two forms: summation and potentiation.
Antagonism- reduction or complete elimination of the pharmacological effect of one medicinal substance by another when used together. Used in the treatment of poisoning and to eliminate unwanted reactions to a drug.
Types of antagonism: direct functional, indirect functional, physical, chemical.
Direct functional - Example: competitive antagonism of beta blockers, antimetabolites.
Indirect functional antagonism - develops in those cases when medicinal substances show the opposite effect on the work of an organ and, at the same time, their action is based on different mechanisms. Example: aceclidine, papaverine.
Physical - occurs as a result of the adsorption of one drug on the surface of another, resulting in the formation of inactive or poorly absorbed complexes. It is used to treat poisoning.
Chemical - arises as a result of a chemical reaction between substances as a result of which inactive compounds are formed. These substances are called antidotes.
If, as a result of the combined use of drugs, a pronounced therapeutic effect is achieved, then the combination of drugs is considered rational and therapeutically appropriate, if undesirable effects develop, such combinations are considered irrational, therapeutically inexpedient (drug incompatibility)
Antiparkinsonian drugs - drugs used in Parkinson's disease, tremor palsy in old age, and with complications of drug therapy.
Classification:
Drugs that activate dopaminergic effects
1.The precursor to dopamine is levodopa
2. Drugs that stimulate dopamine receptors (dopaminomimetics) - bromocriptine, ropinirole.
3 monoamine oxidase B inhibitors - selegiline
Means that inhibit glutamatergic effects - midantan.
Agents that inhibit the cholinergic effect - cyclodol.
Mechanism of action: in parkinsonism, the dopamine content in the basal ganglia is reduced, the interaction of acetylcholine and dopamine is shifted towards the predominance of cholinergic activity. Alignment of the interaction of 2 mediators is achieved by the use of central anticholinergics, or agents that activate the dopaminergic effect, or by the combined use of these drugs.
Indications: parkinsonism, spastic paralysis associated with damage to the extrapyramidal system.
Side effects: dyspepsia, orthostatic hypotension, mental disorders, movement disorders, arrhythmias.
Contraindications: glaucoma, atrial fibrillation, liver and kidney disease, hypertension.
Levodopa, a precursor of dopamine, penetrates the BBB, where it is converted into dopamine. It especially affects hypokinesia, decreases rigidity and tremor.
The most effective remedy. Action in a week. There are many side effects, they decrease with dose reduction.
Bromocriptine - a stimulant of dopamine receptors, reduces prolactin and growth hormone, side effects are often manifested.
Midantan - blocks glutamate receptors, has a beneficial effect on the substantia nigra (decreases in calcium in the cells); causes hypokinesia. The action develops in 1-2 days. There are fewer side effects.
Cyclodol - reduces movement disorders (damage to the extrapyramidal system), effectively reduces tremor.