Antacids are a group of drugs that are bases that react chemically with hydrochloric acid in gastric juice and neutralize it.
1. Absorbable antacids:
Sodium bicarbonate; Precipitated calcium carbonate; Magnesium oxide; Magnesium trisilicate; Basic magnesium carbonate; Magnesium hydroxide
2. combination drugs: Rennie; Gafter's Blend
2. Non-absorbable antacids: Aluminum hydroxide
combination drugs: Protab; Almagel A; Almagel; Phospholugel; Gastal; Compensated; Alugastrin; Maalox; Gelusil varnish
Mechanism of action: Sodium bicarbonate (drinking soda) is a compound that is readily soluble in water and reacts quickly with hydrochloric acid in the stomach. This reaction takes place to produce sodium chloride, water and carbon dioxide.
Sodium bicarbonate acts almost instantly, but its effect is short-lived (10-15 minutes). The carbon dioxide formed during the reaction, accumulating in the stomach, stretches its walls, which leads to irritation of the mucous membrane receptors and increases the release of gastrin, which can lead to a secondary increase in the secretion of hydrochloric acid (syndrome of "recoil" or "secondary hypersecretion").
Calcium carbonate neutralizes hydrochloric acid to form calcium chloride, water and carbon dioxide. The antacid effect develops rapidly, because a suspension of calcium carbonate reacts with acid rather slowly, the drug acts for a longer time than sodium bicarbonate
Magnesium preparations (magnesium oxide, magnesium trisilicate, magnesium carbonate, magnesium hydroxide) are not absorbed when taken orally; neutralize hydrochloric acid to form magnesium chloride. The release of carbon dioxide during the interaction of magnesium preparations (except for magnesium carbonate) with hydrochloric acid does not occur, therefore the antacid effect is not accompanied by secondary hypersecretion. The resulting magnesium chloride is poorly absorbed in the intestine and usually does not have a systemic effect. No alkalosis phenomena are observed. With prolonged use in high doses, hypermagnesemia is possible. Passing into the intestines, magnesium chloride has a laxative effect.
Indications: Aluminum hydroxide: The drug is indicated for diseases with increased secretion of gastric juice (hydrochloric acid): ulcers, gastritis, gastroduodenitis, food poisoning, flatulence. Assign aluminum hydroxide orally in the form of a 4% aqueous suspension, 1-2 teaspoons per dose (4-6 times a day).
Almagel. The drug is prescribed individually, depending on the localization of the process, the acidity of the gastric juice.
Side effects: Aluminum hydroxide: Side effects: not all patients tolerate the astringent effect of the drug well, which may result in nausea; taking aluminum preparations is accompanied by constipation, therefore, aluminum-containing preparations are combined with magnesium preparations. In patients with renal failure, the accumulation of aluminum is not excluded, which may be accompanied by pain in the bones, muscles, encephalopathy.
Contraindications: Hypersensitivity to any component of the drug, severe renal failure, Alzheimer's disease, pregnancy.
4. Antimicrobial agents-derivatives of quinolone. Classification. Mechanism of action. The nature of the action. Spectrum of action. Indications for use. Side effects. Contraindications Comparative evaluation of drugs.
Antimicrobials are medicines used to treat infections caused by bacteria, fungi, viruses.
Classification:
1.Qinolones of the 1st generation (nalidixic acid, oxolinic acid, pipemidic acid)
2.2 Generation (ciprofloxacin, norfloxacin, ofloxacin, pefloxacin, lomefloxacin)
3.3 generation (sparfloxacin, levofloxacin)
4.4 generation (moxifloxacin, gemifloxacin)
The mechanism of action of all quinolones
- blockade of the enzyme DNA gyrase (gyrus - thread) of the microbial cell. This enzyme cross-links two DNA strands and thus participates in the processes of DNA transcription and replication. When DNA gyrase is inhibited, DNA despiralization occurs. This mechanism provides high selectivity and specificity of the quinolones action.
The nature of the action is bactericidal
All quinolones are incompatible with nitrofurans (efficiency drops sharply)
Spectrum of action I generation
non-fluorinated quinolones
narrow - Gr (-) sticks (E. coli, shigella, salmonella, protea, klebsiella)
Do not create a therapeutic concentration in blood and tissues. They are used for urinary tract infections, as they are completely excreted by the kidneys, creating therapeutic concentrations in the urine
Nalidixic acid (nevigramone, blacks)
Used 4 times a day (T1 / 2 1 - 2 hours). The effectiveness is increased by alkalinization of the urine. Microbial resistance develops rapidly
1st generation
non-fluorinated quinolones
• Indications: Acute cystitis, anti-relapse therapy of chronic pyelonephritis (in acute pyelonephritis, it is ineffective, since the drugs accumulate little in the kidney tissues)
Side effects: Gastrointestinal tract - heartburn, epigastric pain, nausea, vomiting, diarrhea (taken after meals)
CNS - an exciting effect, can manifest itself with tremors, insomnia, paresthesias, a decrease in the seizure threshold
Blood - leukopenia, thrombocytopenia, in patients with genetic deficiency of glucose-6-phosphate dehydrogenase - hemolytic anemia
Liver - cholestatic jaundice, hepatitis
• Contraindications: Fluoroquinolone: History of convulsive syndromes
• Deficiency of the enzyme glucose-6-phosphate dehydrogenase
• Pregnancy (possibly inhibition of the development of cartilage tissue in the fetus)
• Lactation
• Children's age (up to 10 - 12 years old due to the possibility of inhibition of the development of cartilage tissue)
Comparative characteristics:
Nifuroxazide (enterofuril) is used for intestinal infections (acute infectious diarrhea, enterocolitis). Practically not absorbed in the digestive tract. Does not disturb the normal intestinal microflora
Furazolidone is currently used only for giardiasis as a reserve drug. NB! In combination with alcohol, it can cause a teturam-like reaction. Inhibits MAO, therefore, in combination with other MAO inhibitors, sympathomimetics, tricyclic antidepressants and tyramine-containing foods, there is a risk of developing a hypertensive crisis
Nifuratel (makmiror) is used for intestinal infections (acute infectious diarrhea, enterocolitis), giardiasis, intestinal amebiasis, trichomonas vulvovaginitis
Furacilin is used as an antiseptic for treating wounds, skin, mucous membranes, for washing serous and articular cavities.
With the combined use of medicinal substances, their effect can be enhanced (synergism) or weakened (antagonism)
Synergy is the 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 is a decrease or complete elimination of the pharmacological effect of one drug 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 - arises from 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 - occurs 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)
Sleeping pills are medicinal substances that cause a person to experience a state close to natural sleep.
It is used for insomnia to facilitate falling asleep and to ensure a normal duration of sleep.
Classification:
I. hypnotics with a non-narcotic type of action:
1. Benzodiazepine receptor agonists:
1) Derivatives of benzodiazepine - short-acting triazolam,
medium duration of action-lorazepam, lorazepam, nitrazepam, long-acting-phenazepam, diazepam.
2) Preparations of different chemical structures: zopiclone, zolpidem, zaleplon.
2. Agonists of melatonin receptors (synthetic analogs of melatonin): ramelteon, melaxen.
3. Blockers of H1 - histamine receptors (ethanolamine derivative): doxylamine, donormil.
II.Sleeping drugs with a narcotic type of action:
1. Heterocyclic compounds (derivatives of barbituric acid): phenobarbital, sodium ethaminal.
2. Compounds of the aliphatic series: chloral hydrate, sodium oxybutyrate, bromized.
The mechanism of action of benzodiazepine derivatives and drugs of different chemical structure: They interact with benzodiazepine receptors, increase their sensitivity to GABA, melatonin receptor agonists are analogous to the hormone melatonin, the main function of which is the regulation of biological rhythms. The drugs stimulate melatonin receptors, histamine receptor blockers block these receptors and cholinergic receptors in the reticular formation and enhance inhibitory processes, aliphatic compounds are converted in the central nervous system into an inhibition mediator - GABA.
Indications: insomnia due to anxiety, stress; neuroses, removal of seizures, alcoholic obsession.
Side effects: drowsiness, lethargy, the phenomenon of recoil, hypoventilation, impaired coordination, decreased blood pressure, irritability, depression, allergic reactions.
Contraindications: drug addiction, myasthenia gravis, respiratory, renal failure, hepatitis, pregnancy, blood diseases. Long-term use of barbiturates causes mental and physical drug dependence.
Benzodiazepine derivatives have a sedative, hypnotic, anticonvulsant and muscle relaxant effect, in small doses they have an anti-anxiety and sedative effect, in high doses - hypnotic, anticonvulsant. shorten the phase of REM sleep, but to a lesser extent than derivatives of barbituric acid.
Preparations of different chemical structures have a selective hypnotic effect, do not cause recoil syndrome, and do not disrupt the physiological structure of sleep.
Agonists of melatonin receptors have an adaptogenic sedative hypnotic effect, normalize circadian rhythms, addiction and drug dependence do not develop, there is no recoil phenomenon, and do not disturb the physiology of sleep.
Blockers of H-histamine receptors in terms of effectiveness, the action is similar to benzodiazepine derivatives, has a daytime aftereffect, low toxicity.
Heterocyclic compounds in high doses cause anesthesia, induction of liver enzymes, material accumulation, post-somnic effect, with prolonged use - addiction, drug dependence.
Class II - substances that limit the neuro-sympathetic effects on the heart.
Classification:
1) Non-cardioselective: -Anaprilin (beta1,2), pindolol, timolol, nadolol.
2) Cardioselective: -Metoprolol (beta1), talinolol (beta 1), nebivolol, atenolol, bisoprolol.
Each of the presented groups is subdivided into two subgroups:
Drugs without sympathomimetic activity (without SMA)
Drugs with sympathomimetic activity (with SMA)
Mechanism of action: blockade of beta-adrenergic receptors of the myocardium, blood vessels, bronchi. They reduce automatism, slow down conduction, increase the effective refractory period (in the AV node), reduce the force of myocardial contraction, reduce the sympathetic effect, and reduce the need for oxygen.
Indications: ischemic heart disease, arterial hypertension, tachyarrhythmia (atrial and ventricular).
Side effects: increase the tone of the bronchi (not possible with bronchial asthma), bradycardia, allergies, conduction disturbances, impaired peripheral circulation, hyperglycemia, withdrawal syndrome, weakness, lethargy.
Contraindications: bradycardia, heart failure, bronchial asthma, diabetes mellitus, pregnancy, hypotension, impaired peripheral circulation.
Anaprilin - reduces heart rate and the strength of heart contractions, can provoke bronchospasm, reduces the activity of the sinus node and excitability, slows down the rhythm, reduces contractility, heart function decreases.
Talinolol - reduces contractility less, lowers blood pressure.
The most cardioselective drugs: nebivolol, bisoprolol.
Celiprolol blocks beta 1 receptors, but at the same time has some stimulating effect on beta 2 receptors, so it has no side effects from the bronchi, carbohydrate and lipid metabolism.
Nebivolol has a vasodilating effect by increasing the synthesis and release of nitric oxide, and has antioxidant properties.
Esmolol is the shortest-acting drug used only as an intravenous infusion.
1. Neurotoxic - damage to 8 pairs of cranial nerves, neuromuscular block.
2. Nephrotoxic; 3. Inhibition of hematopoiesis; 4. Irritation of the gastrointestinal tract; 5. Teratogenic action; 6. Dysbacteriosis, candidomycosis; 7. Allergic reactions - skin, anaphylactic shock, serum sickness, agranulocytosis; 8. Reduction of the therapeutic effect - with the indiscriminate use of antibiotics, non-compliance with dosages, frequency of use, course doses.
The success of antibiotic therapy depends on the fulfillment of the following basic conditions:
- it is necessary not only to choose the right antibiotic, but also to cancel it in a timely manner;
- when finishing antibiotic therapy, the drug is canceled immediately, and not gradually;
- the duration of the course of antibiotic treatment should be at least 6 - 8 (sometimes 10) days;
- with combined treatment with antibiotics with glucocorticoids, the antibiotic is canceled 3 to 5 days after the end of the course of hormone therapy;
- uncontrolled prescription of antibiotics leads to allergization of patients and an increase in the number of antibiotic-resistant microorganisms;
- the method of administration of antibiotics is selected depending on the localization of the infection, must be individual and quickly create the optimal concentration of the drug in the focus of infection;
- the frequency of antibiotic administration is determined by the duration of the bacteriostatic or bactericidal concentration of the drug in the blood;
- the maximum effectiveness of antibiotics is achieved when combined with other antimicrobial, antihistamines and vitamin preparations.