What is bactericidal and bacteriostatic action. Side effects of mepacrine. Side effects of fluoroquinolones

The global effect of antibiotics on bacteria or other microorganisms can be expressed in two forms: bactericidal and bacteriostatic effects. With the bactericidal action of the antibiotic, bacterial growth does not resume. Antibiotics that destroy the cell wall. The invention relates to medical and veterinary bacteriology and can be used to differentiate antibiotics by bactericidal bacteriostatic effect.

The bacteriostatic effect of drugs is a temporary suppression of the ability of microorganisms to reproduce in the body. Antibiotics such as various penicillins, streptomycin, neomycin, kanamycin, vancomycin, and polymyxin have a bactericidal effect. When removing an antibiotic from environment microorganisms can develop again. In most cases, when treating infectious diseases, the bacteriostatic effect of antibiotics in combination with the body’s defense mechanisms ensures the patient’s recovery.

Use of antibiotics in veterinary medicine and animal husbandry - The use of antibiotics in veterinary medicine began immediately after their discovery. ANTIBIOTICS are chemical substances produced by microorganisms that can inhibit the growth and cause the death of bacteria and other microbes. In the first case, microorganisms die, and then they talk about the bactericidal effect of this preservative, in the second, deep inhibition occurs vital functions microorganism

To exert their effect, antibacterial drugs in most cases must penetrate inside the cell, and the main barrier to their path in this case is the cell wall of the microorganism. When identifying a microorganism, it is necessary to use antibacterial agent, which has the narrowest spectrum of action. This means that it should have a damaging effect only on the microorganism, without affecting the macroorganism.

For many antimicrobial agents, the intimate mechanism of action is not completely clear. Antimicrobial agents can have a bactericidal or bacteriostatic effect depending on the depth of their effect on the microorganism. The bactericidal effect leads to the death of the microorganism; for example, beta-lactam antibiotics and aminoglycosides act this way. The bacteriostatic effect consists of temporarily suppressing the growth and reproduction of microorganisms (tetracyclines, sulfonamides).

Bacteriostatic drugs should not be combined with bactericidal drugs. However, the concepts of bactericidal and bacteriostatic are not absolute, since very often increasing the concentration of a bacteriostatic drug can give a bactericidal effect.

There are two main mechanisms of action of antibiotics:

The type of action of antibiotics is determined by the microorganism, the properties of the antibiotic, and their concentration. However, the most accessible and proven bactericidal type of action is the absence of the ability of cells to grow and reproduce after removal of the antibiotic. These enzymes are called extended-spectrum betalactamase.

With the bacteriostatic effect of the antibiotic on bacteria, after the addition of penicillinase, bacterial growth appears in those wells where it was not detected after the second stage of the study. Example 1. Determination of the bactericidal and bacteriostatic effect of benzylpenicillin sodium salt on museum bacterial cultures. However, for St. aureus, Y. pseudotuberculosis and B. сereus - highly sensitive to the antibiotic, this difference did not exceed a twofold value.

Possibility of using antibiotics in pregnant and lactating women

In a parallel series with added penicillinase, bacterial growth (yellowing and turbidity of the medium) was observed in all wells, including at the maximum concentration of the antibiotic. The discharge of the 6th T-va was added to all wells. After 6 hours, a delay in bacterial growth was detected in the first three wells at the antibiotic concentration. 3. The method according to claim 1, characterized in that the concentration of the antibiotic is reduced by the method of serial dilutions.

How can antibiotics be introduced into the body?

1) Bactericidal mechanism - complete suppression of bacterial growth through action on the vital cellular structures of microorganisms, therefore causing their irreversible death. If you can't stand it full course treatment and stop taking the bacteriostatic antibiotic early, the symptoms of the disease will return. After administration, the antibiotic ends up in the blood and then in a specific organ.

Currently, the problem of antibiotic resistance of microorganisms (resistance of microorganisms to the action of antibacterial drugs) is acute. In small doses, antibiotics are dangerous and affect the development of bacterial resistance. Milk and dairy products should be taken no earlier than 4 hours after taking the antibiotic or completely avoid them during the course of therapy. For example, the effect of hormonal contraceptives is reduced when taking antibiotics.

According to statistics, up to 70-85% of children with pure age receive antibiotics in Russia. viral infections, that is, antibiotics were not indicated for these children. You should also not hesitate to prescribe antibiotics for mycobacterial infection (tuberculosis), where specific antibacterial drugs are key in the treatment regimen. This is due, first of all, to the inevitable side effects of drugs of any severity. Antibiotics are a group of organic substances of natural (natural) or semi-synthetic origin that have the ability to destroy or slow down the growth of bacteria, fungi and tumors.

What is an antibiotic?

This substance is natural antibiotic– chemical weapons of the microworld. Indeed, the production of antibiotics is one of the most advanced methods of competition between microorganisms in nature.

Features of taking antibiotics:

But this was only the beginning of the era of antibiotics. It turned out that some antibiotics can be used to treat fungal infections or to destroy malignant tumors. The most important point in understanding the phenomenon of antibiotics is to determine the horizon of their action. And vice versa: antibiotics are absolutely ineffective against viruses, which, as is known, belong to subcellular microorganisms.

With a bacteriostatic effect, the death of microorganisms does not occur, only the cessation of their growth and reproduction is observed. One of the most important signs for antibiotics is the type of their action on microorganisms - bacteriostatic and bactericidal (Navashin S.M., Fomina I.P. Rational antibiotic therapy. The purpose of the invention is to increase the reliability of the method and speed up the determination by distinguishing the type of bacteriostatic and bactericidal action of antibiotics.

For millennia, bacteria have caused great amount diseases against which medicine was powerless. However, in 1928, British bacteriologist Alexander Fleming made an accidental, but truly epoch-making discovery. He studied the various properties of staphylococci, which he grew in laboratory dishes. One day, after a long absence, Fleming noticed that a mold had formed on one of the cups, which had killed all the staphylococci. The first antibiotic, penicillin, was isolated from such molds.

The era of antibiotics allowed medicine to take huge steps forward. Thanks to them, doctors were able to effectively treat numerous infectious diseases that previously led to death. Surgeons were able to perform difficult and lengthy operations, since antibiotics greatly reduced the incidence of postoperative infectious complications.

Over time, pharmacologists found more and more new substances that had a detrimental effect on bacteria. Today, doctors have a wide range of antibacterial drugs in their arsenal.

Based on their effect on bacteria, they are divided into:

1. Bacteriostatic antibiotics– do not kill bacteria, but block their ability to reproduce. Of this group of drugs, the Italian antibiotic Zithromax, which contains 500 mg of azithromycin, has an excellent therapeutic effect. In high concentrations the drug has a bactericidal effect.
2. Bactericidal antibiotics– destroy bacteria, which are then eliminated from the body. Fluoroquinolone drugs, such as ciprofloxacin, have proven themselves to be excellent. It is part of the highly effective Italian antibiotic Ciproxin 250 mg and Ciproxin 500 mg.

Based on their chemical structure they are divided into:

1. Penicillins– bactericidal antibiotics that are produced by fungi of the genus Penicillium. Drugs: Benzylpenicillin, Oxacillin, Ampicillin, Amoxicillin, etc.
2. Cephalosporins– bactericidal antibiotics. Used to destroy a wide range of bacteria, including penicillin-resistant ones. Drugs: I generation – Cefazolin, Cephalexin, II generation – Cefuroxime, Cefaclor, III generation – Ceftriaxone (in powder form + water for injection: Fidato 1g/3.5 ml, Rocephin 1g/3.5 ml), Cefixime (Supraceph 400 mg, Cefixoral 400 mg, Suprax 400 mg), Cefodizim (Timesef 1g/4 ml powder + water for injection), IV generation - Cefepime.
3. Carbopinema– reserve antibiotics with bactericidal action. They are used only for very severe infections, including hospital-acquired ones. Drugs: Imipenem, Meropenem.
4. Macrolides– have a bacteriostatic effect. They are among the least toxic antibiotics. In high concentrations they exhibit a bactericidal effect. Drugs: Erythromycin, Azithromycin (Zithromax 500 mg), Midecamycin, Clarithromycin (Klacid 500 mg - has a wide spectrum of action. Klacid 500 mg also exists in the form of modified-release tablets).
5. Quinolones and fluoroquinolones– very effective bactericidal agents wide spectrum of action. If any other drug does not have a therapeutic effect, then they resort to antibiotics of this particular group. Drugs: Nalidixic acid, Ciprofloxacin (Ciproxin 250 mg and Ciproxin 500 mg), Norfloxacin, etc.
6. Tetracyclines– bacteriostatic antibiotics, which are used to treat diseases of the respiratory system, urinary tract and severe infections such as anthrax, tularemia and brucellosis. Medicines: Tetracycline, Doxycycline.
7. Aminoglycosides– bactericidal antibiotics with high toxicity. Used to treat severe infections such as peritonitis or blood poisoning. Drugs: Streptomycin, Gentamicin, Amikacin.
8. Levomycetins– bactericidal antibiotics, have an increased risk of serious complications when taken orally. The use of the tablet form is limited - only for serious infections of the bone marrow. Preparations: Chloramphenicol, Iruksol ointment for external use, Syntomycin.
9. Glycopeptides– have a bactericidal effect. Bacteriostatically act against enterococci, some types of staphylococci and streptococci. Drugs: Vancomycin, Teicoplanin.
10. Polymyxins– bactericidal antibiotics with a fairly narrow spectrum of action: Pseudomonas aeruginosa, Shigella, Salmonella, E. coli, Klebsiella, Enterobacter. Drugs: Polymyxin B, Polymyxin M.
11. Sulfonamides– are used quite rarely today, since many bacteria have developed resistance to them. Drugs: Sulfadimidine, Sulfalene, Sulfadiazine.
12. Nitrofurans– have a bacteriostatic and bactericidal effect depending on the concentration. Rarely used for uncomplicated infections with light current. Drugs: Furazolidone, Nifuratel, Furazidin.
13. Lincosamides– bacteriostatic antibiotics. In high concentrations they exhibit a bactericidal effect. Drugs: Lincomycin, Clindomycin.
14. Anti-tuberculosis antibiotics– specialized antibiotics for the destruction of Mycobacterium tuberculosis. Drugs: Isoniazid, Rifampicin, Ethambutol, Pyrazinamide, Prothionamide, etc.
15. Other antibiotics - Gramicidin, Heliomycin, Diucifon, and others, including those with an antifungal effect - Nystatin and Amphotericin B.

Each antibiotic has its own mechanism of bactericidal or bacteriostatic action. Therefore, drugs from each group are able to act only on certain types of microorganisms. For this reason, when deciding the question “Which antibiotic is best?” You must first accurately identify the causative agent of the infection, and then take exactly the antibiotic that is effective against this bacterium.

There is also another method of treatment, which is very popular among modern doctors and patients. They prescribe antibacterial drugs with a very broad spectrum of action. This allows you to avoid identifying the type of bacteria and begin treatment immediately. If the selected drug does not create the required therapeutic effect, then it is changed to another broad-spectrum antibiotic.

This approach allows the patient to save significant money. Judge for yourself: a good set of tests to detect a genitourinary infection will cost the patient more than 30,000 rubles. And the packaging the newest antibiotic Zithromax costs only 4,500 rubles. The antibiotic Zithromax is a broad-spectrum antibiotic, it covers a significant part of the spectrum of all common infections and the likelihood of a cure without identifying the pathogen is very high. And if the choice still turns out to be inaccurate, then an antibiotic is prescribed that covers a different spectrum possible infections, which already brings the effectiveness of treatment closer to 100%. At the same time, the drugs also destroy a number of other pathogenic bacteria, which have not yet managed to cause harm to the body noticeable during general diagnostics. So treatment with broad-spectrum antibiotics has become widespread and is quite justifiable and will probably remain popular for a very long time, until the cost and reliability of tests improve by at least an order of magnitude.

We looked at 15 types of antibiotics. It would seem that with such a huge range of diverse antibiotics, the problem of bacterial infections should be solved forever. However, under the influence of drugs, bacteria began to develop various protective mechanisms. Gradually, some of them completely lost sensitivity to certain antibiotics. Fleming also noted that if bacteria are exposed to small doses of penicillin or its effect is short-term, then the bacteria do not die. Moreover, they became resistant to regular doses of penicillin.

Today, antibacterial drugs are freely available. Many patients often immediately begin taking antibiotics at the slightest sign of a cold. At the same time, they forget that such colds are often caused by viruses. Antibiotics have absolutely no effect on viruses. Taking an antibiotic in this case will only increase the toxic load on the body and contribute to the progression of the disease.

Therefore, it is extremely important to comply with certain rules of antibacterial therapy:

1. Antibiotics should only be taken when bacterial infections!
2. Strictly observe the dosage of the drug, frequency of administration and duration of treatment! Usually the drugs are taken for 7 days, unless otherwise stated in the attached instructions.
3. It is highly desirable to determine the type of bacteria of the pathogen and its sensitivity to different types of antibacterial drugs. Then you can take a narrow-spectrum antibiotic (specifically against this pathogen). Inadequate use of broad-spectrum antibiotics leads to the emergence of resistant bacteria.
4. To increase the effectiveness of treatment for severe infections, you can take antibiotics with different spectrums of action or with different routes of administration (injections, tablets, ointments, suppositories, etc.).
5. Antibiotic therapy is recommended to be supplemented with prebiotics and probiotics, which help preserve normal microflora intestines (Bifidumbacterin, Bifinorm, Lactobacterin, Lactulose, Linex, Hilak-forte).

Thus, it is necessary to clearly understand when, how and which antibacterial drugs should be taken. The antibacterial drug should be taken strictly according to the instructions. Follow the rules of antibacterial therapy - this will help the antibiotic act effectively and quickly. With all the development of medical science, there is no antibiotic for all bacteria. Identify the specific pathogen and target it with a targeted antibiotic. Antibiotics will help you a lot if you help antibiotics, and choosing a targeted antibiotic is the best course of action.

Proper use of antibiotics is not only the key to a quick recovery. Correct treatment helps maintain the effectiveness of the antibacterial drug for you for many years. After all, after this effective treatment no pathogenic bacteria remain in the body at all. In this case, there can be no question of the formation of bacteria resistant to this drug.

Antiseptics is a set of measures aimed at destroying infectious agents on the surface of the body (skin, mucous membranes, wounds), cavities.

Disinfection is the destruction of pathogens of infectious diseases in the external environment.

In practical terms, two actions are distinguished: bacteriostatic and bactericidal.

The bacteriostatic effect is to delay the proliferation of bacteria while the substance continues to act.

The bactericidal effect is expressed in the complete killing of microorganisms.

Often the same substances can different concentrations can have both bacteriostatic and bactericidal effects. A bactericidal effect requires a higher concentration than a bacteriostatic effect.

Chemical antiseptics is the destruction of microorganisms in a wound, pathological focus or the patient’s body using various chemicals.

The mechanism of action of such antiseptic substances is different: some of them precipitate protein, which mainly consists of bacterial cell membranes; others cause the death of bacteria by penetrating into their cells and affecting their plasma; still others create unfavorable conditions for the growth of bacteria and their reproduction.

Soluble aromatic compounds with an antiseptic effect are typical protoplasmic poisons, which are already in weak solutions inhibit the proliferation of bacteria, and in stronger concentrations kill all microorganisms. Many of them belong to the most commonly used antiseptic and disinfectant substances.

Examples of antiseptics

Salicylic acid (C6H4(OH)COOH). used as a good antiseptic for various rashes (in a 1% solution), calluses (10%), as a deodorizing agent in the form of powders for foot sweats (1-2%); in anti-freckle products - as promoting desquamation of the epidermis (up to 1-1.2%), against cracks in the skin (1%).

When mixing solutions of 2 parts salicylic acid and 1 part boric acid, a very bitter boric acid is obtained. salicylic acid, serving as an excellent antiseptic, many times superior in effect to boric and salicylic acids taken separately. The combination of salicylic acid with benzyl alcohol (a good preservative) also works very well.

Boric (ortho-boric) acid (H3BO3) is a weak acid, but at high temperatures it acquires the properties of a very strong acid. When mixed with salicylic acid, it produces a bitter compound (boronic salicylic acid), which has a very strong antiseptic effect, almost equal in strength to carbolic acid.

When boric acid is mixed with fats, its antiseptic properties are reduced to almost zero. In this case, it is much more advisable to use boric salicylic acid or benzoic acid in this case. Use 1-5% aqueous and alcohol-water solutions.

Solutions of boric acid are mildly irritating and do not precipitate protein. Boric acid exhibits a bacteriostatic effect only in 2-4% solutions.

Benzoic acid (C6H5COOH) is used as a strong antiseptic and is much stronger than salicylic acid. Benzoic acid slightly irritates the skin and promotes peeling of the epidermis, so it is used to remove freckles and spots. It is soluble in fats and is used for preserving fats used in the preparation of cosmetic creams. Up to 1% is added to cosmetic preparations.

Benzyl alcohol (C7H8O) is an energetic antiseptic, significantly superior to phenol, but devoid of its toxicity. Physiologically flawless. Used as antiseptic in creams, lotions, etc. The antiseptic effect of benzyl alcohol is further enhanced by its combination with boronosalicylic acid.

Bornosalicylic acid is a strong and harmless antiseptic and preservative, its action is 10-15 times greater than that of phenol, but without its disadvantages, it does not irritate or smooth the skin.

Glyceroboride (boroglyceride) - is chemical compound, in which 3HO glycerol is replaced boric acid when water is released: C3H5(OH)3 + H3BO3 > C3H5BO3 + 3H2O

Of the glyceroboride compounds, its sodium and calcium salts are of interest. Both salts are very gentle, non-irritating, non-toxic antiseptics, and are not inferior in potency to phenol.

Naphthalene is a greasy substance Brown, weak specific odor. It is obtained from naphthalan oil. Well lubricates and softens the skin. Naphthalan ointment is prepared from naphthalan.

It has a softening, slightly analgesic effect on the skin. It has both bacteriostatic and bactericidal effects. Promotes resorption of infiltrates. It has anti-inflammatory, epithelializing and granulating properties.

Directions for use: for seborrhea of ​​the face or scalp, wipe it with cotton wool soaked in naphthalene alcohol, first daily, and then every other day until a positive result is achieved. This alcohol is equally suitable for the treatment of dry seborrhea of ​​the scalp.

Resorcinol, or metadioxybenzene C6H4(OH)2. When ground with two parts of camphor or menthol, it gives oily liquids - camphor resorcinol or menthol resorcinol. Like salicylic and carbolic acids, it has strong anti-putrefactive properties, but is less caustic and poisonous. It energetically coagulates protein and therefore has a corrosive and cauterizing effect on the skin, painlessly exfoliates the epidermis.

It is used in the form of 2-5 percent creams or in the form of liquids for acne, against seborrhea of ​​the skin and hair loss, and in a 5-10 percent solution for freckles.

Thymol (C6H3CH3C3H7OH). In therapeutic terms, thymol is similar to carbolic acid, but its effect is somewhat weaker and milder. It has a pleasant smell and is less toxic. Thymol is a good anti-putrefactive agent, used in dental preparations, to lubricate burns, while acting as a painkiller.

In an amount of 0.1-0.5% thymol is included as component in all kinds of dental products, creams, lotions; in soaps, under the influence of free alkali present in them and formed during hydrolysis during washing, thymol is converted into indifferent sodium thymolate.

Thioresorcinol (C6H4O2S2). It combines the effects of resorcinol and sulfur, therefore it is of great interest for cosmetics and in dermatological practice.

Formalin is a 40% solution of formaldehyde.

A colorless liquid with a pungent odor, easily mixed with water and alcohol in all proportions.

It has tanning and antiseptic properties, especially pronounced in an alkaline environment. Formalin tans cell proteins and coagulates them.

In some cases it can sensitize the skin, so its use requires caution. In case of excessive sweating, it serves as a means of reducing the secretion of sweat glands, and also as an antiseptic in the form of 0.5-1% solutions.

In the presence of skin irritations and cracks, formalin is contraindicated.

It would be advisable to completely abandon the introduction of formalin into cosmetical tools, due to its carcinogenicity.

Furacilin-5-nitro-2-fufurylene-semicarbazone is a yellow, finely crystalline, slightly bitter powder, a strong antiseptic that acts on gram-positive and gram-negative microbes, large viruses and some protozoa. Inhibits the growth of microorganisms that have become resistant to antibiotics and sulfonamides. Furacilin solutions do not irritate the skin and promote granulation and wound healing. It has been used in cosmetics, especially in combination with sulfur, for the care of oily facial skin prone to acne.

Furacilin solutions do not deteriorate over time, however water solution should be protected from infection by fungi, since furatsilin does not have fungicidal properties. Furacilin is considered a harmless remedy, but there are reports of cases of leukoderma and graying as a result of its use.

Quinozol [C9H7(OH)2N2. H2SO4] 8-hydroxyquinoline sulfate. An extremely strong and harmless antiseptic. At a dilution of 1:300,000 it inhibits the growth of lower microorganisms, and at a dilution of 1:40,000 it kills them. Excellent remedy for cosmetic and hygiene preparations.

The use of quinzol is very advisable:

• 1. in products against freckles, skin spots and acne (1: 500-1000);
• 2. in disinfectants, intended for use after shaving for the purpose of disinfection, elimination of irritation and rashes on the skin, and as a hemostatic agent (1: 1000-2000);
• 3. against dandruff and hair loss (1: 500);
• 4. for washing hair and disinfecting skin (1: 1000);
• 5. in soaps (1: 200);
• 6. anti-sweat (1: 1000);
• 7. for burns (1: 1000), especially in a mixture with thymol;
• 8. as a preservative for fats and aqueous preparations (1: 5000-10000).

Zinc carbolic sulfur or zinc carbolic sulfur Zn(C6H4OHSO3)2+7H2O. Added to lotions as an antiseptic for skin disinfection after shaving.

Hydrogen peroxide (H2O2). Used as an energetic oxidizing, disinfectant, antiseptic and whitening (bleaching) agent for freckles and spots on the skin, in dental products for whitening teeth, and for bleaching hair. IN the latter case it brings undoubted harm, since hair from frequent use hydrogen peroxide becomes thin, brittle and brittle.

The antiseptic effect of hydrogen peroxide is based on the fact that in the light or from contact with organic matter (skin, hair), it decomposes into water and oxygen, which is released in the form of an energetic allotropic form - ozone.

Bromothymol С10Н13ОBr - a product of bromination of thymol, is introduced into liquid preparations for refreshing and disinfecting air diluted with alcohol 1: 5000. In this concentration, bromothymol has no noticeable odor.

Table - Requirements for antiseptics and disinfectants.

Based on the nature of the action of antibiotics on bacteria, they can be divided into two groups:

1) AB of bacteriostatic action

2) AB with bactericidal action

Bacteriostatic antibiotics in concentrations that can be created in the body inhibit the growth of microbes, but do not kill them, while exposure to bactericidal antibiotics in similar concentrations leads to cell death. However, at higher concentrations, bacteriostatic antibiotics can also have a bactericidal effect. Bacteriostatic antibiotics include macrolides, tetracyclines, chloramphenicol and others, and bactericidal antibiotics include penicillins, cephalosporins, ristocetin, aminoglycosides and others.

In recent years, great strides have been made in studying the mechanism of action of antibiotics at the molecular level. Penicillin, ristomycin (ristocetin), vancomycin, novobiocin, D-cycloserine disrupt the synthesis of the bacterial cell wall, that is, these antibiotics act only on developing bacteria and are practically inactive against dormant microbes. The end result of the action of these antibiotics is the inhibition of the synthesis of murein, which, along with teichoic acids, is one of the main polymer components of the bacterial cell wall. Under the influence of these antibiotics, newly formed cells lacking a cell wall are destroyed. If the osmotic pressure of the surrounding liquid is increased, for example, by adding sucrose to the medium, then bacteria deprived of a cell wall are not lysed, but are transformed into spheroplasts or protoplasts (see Bacterial Protoplasts), which, under appropriate conditions, are capable of multiplying like L-forms of bacteria. After removing the antibiotic, the microbial cell, if it has not died, again becomes capable of forming a cell wall and turning into a normal bacterial cell. There is no cross-resistance between these antibiotics, because their points of application in the process of murein biosynthesis are different. Since all of the above antibiotics affect only dividing cells, bacteriostatic antibiotics (tetracyclines, chloramphenicol), which stop cell division, reduce the activity of bactericidal antibiotics, and therefore their combined use is not justified.

The mechanism of action of other antibacterial antibiotics - chloramphenicol, macrolides, tetracyclines - is to disrupt the protein synthesis of the bacterial cell at the ribosome level. Like antibiotics that inhibit murein formation, antibiotics that inhibit protein synthesis act at different stages of this process and therefore do not have cross-resistance with each other.

The mechanism of action of aminoglycoside antibiotics, for example streptomycins, is primarily to suppress protein synthesis in the microbial cell due to the effect on the 30 S-ribosomal subunit), as well as disruption of the reading of the genetic code during translation.

Antifungal antibiotics polyenes disrupt the integrity of the cytoplasmic membrane of the fungal cell, as a result of which this membrane loses its properties as a barrier between the contents of the cell and external environment, providing selective permeability. Unlike penicillin, polyenes are also active against resting fungal cells. Antifungal action polyene antibiotics are caused by their binding to sterols contained in the cytoplasmic membrane of fungal cells. The resistance of bacteria to polyene antibiotics is explained by the absence of sterols in their cytoplasmic membrane that bind to polyenes.

Antitumor antibiotics, unlike antibacterial ones, disrupt the synthesis of nucleic acids in bacterial and animal cells. Antibiotics actinomycins and aureolic acid derivatives suppress DNA-dependent RNA synthesis by binding to DNA, which serves as a template for RNA synthesis. The antibiotic mitamicin C has an alkylating effect on DNA, forming strong covalent cross-links between two complementary DNA helices, thereby disrupting its replication. The antibiotic bruneomycin leads to a sharp inhibition of DNA synthesis and its destruction. Rubomycin also has a suppressive effect on DNA synthesis. All these reactions are probably primary and main in the action of the antibiotic on the cell, since they are observed already at very weak concentrations drugs. Antibiotics in high concentrations disrupt many other biochemical processes occurring in the cell, but, apparently, this effect of antibiotics is of secondary importance in the mechanism of their action.

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Antibiotics

2. antibiotics in surgery. Classification, indications for use. Possible complications. Prevention and treatment of complications

In different groups of ayatibiotics, the chemical mechanism of their effect on bacteria is different; Many antibiotics inhibit the synthesis of substances that form bacterial walls, while others interfere with protein synthesis by bacterial ribosomes. Some types of antibiotics affect DNA replication in bacteria, and some disrupt the barrier function of cell membranes. In table Table 5.1 provides a list of the most commonly used antibiotics and their classification depending on the inhibitory effect on the functional characteristics of bacteria.

Table 5.1. Classification of antibiotics depending on their inhibitory effect on bacterial functions

The fundamental principles of antibiotic therapy are the following: 1) the use of a drug that is effective against the identified pathogen, 2) the creation of adequate access of the antibiotic to the microbial focus, 3) the absence of a toxic side effect of the drug, and 4) strengthening the body's defenses to achieve maximum antibacterial effect. Material for bacteriological research If possible, should always be taken before starting antibiotics. After receiving a bacteriological conclusion about the nature of the microflora and its sensitivity to antibiotics, the antibiotic can be changed if necessary. Before receiving the results of a bacteriological study, the doctor chooses an antibiotic based on clinical manifestations infection and own experience. Many infections may be polymicrobial and may therefore require a combination of antibiotics to treat.

Antibiotic therapy is inevitably accompanied by changes in the composition of the normal intestinal microflora. Colonization refers to the quantitative manifestations of changes in microflora caused by the use of antibiotics. Superinfection is a new infectious disease caused or potentiated by antibiotic therapy. Superinfection is often the result of colonization.

PREVENTION OF INFECTION USING ANTIBIOTICS

When treating potentially infected wounds, antibiotics are prescribed to prevent infectious complications, while the use of antibiotics complements surgical treatment of the wound, but does not replace it. The need for prophylactic antibiotics in addition to proper surgical debridement is dictated by the risk associated with microbial contamination. After operations performed under aseptic conditions, the risk is minimal and antibiotics are not needed. Operations with a risk of microbial contamination are those that involve opening the lumen or contacting the hollow organs of the respiratory, urinary, or gastrointestinal tracts. “Dirty” operations are those that involve the leakage of intestinal contents or the treatment of wounds not associated with surgery. “Dirty” wounds are those that come into contact with a previously existing infectious focus, such as intraperitoneal or perirectal abscesses.

In addition to the degree of contamination, the risk of which is present during certain operations, the possibility of developing infectious complications is influenced by factors related to the condition of the patient's body. A special risk group for the development of infectious complications are patients with low nutrition or, conversely, obesity, the elderly and those with immune deficiency.

Shock and/or poor blood supply to tissue in the surgical area also increases the risk of infectious complications. In these cases, infection prophylaxis with antibiotics should be considered. In principle, the use of prophylactic antibiotics should begin early enough to ensure therapeutic concentrations of the drug in the tissues and in the body during surgery. Often repeated intraoperative administration of the antibiotic is necessary to maintain its adequate concentration in the tissues. The duration of surgery and the half-life of antibiotics in the body are significant factors that must be taken into account during prophylaxis.

In table Table 5.2 provides a short list of operations in which prophylaxis with antibiotics usually gives the desired result.

Table 5.2. Operations and conditions for which antibiotic prophylaxis is appropriate

INTESTINAL ANTISEPTICS

Prevention of infection of intraperitoneal wounds during intestinal operations consists of a preliminary reduction in the volume of normal microflora. One of standard methods consists of a two-day fast with water, and then intensive bowel cleansing with enemas the day before surgery. Neomycin and erythromycin for enteral administration, which are not absorbed from the gastrointestinal tract, are prescribed 1 g each at 13, 14 and 23 hours a day before surgery. This method of intestinal antisepsis has been shown to reduce the incidence of postoperative bacterial complications, but does not prevent complications associated with errors in surgical technique and poor tactical decisions.

ANTIMICROBIALS

It is important that antibiotic treatment is directed against a pathogen that is sensitive to it, and not just the treatment of a specific nosological form. Effective antimicrobial therapy requires accurate bacteriological diagnostics with determination of the sensitivity of the isolated microflora to certain antibiotics. When assessing the effectiveness of antibiotic therapy, it is important to pay attention to the dynamics of leukocytosis in peripheral blood. The various antibiotics commonly used in surgical practice are described below.

Penicillins are antibiotics that block the synthesis of proteins that make up the bacterial wall. The B-lactam ring forms the basis of their antibacterial activity. Bacteria that produce p-lactamase are resistant to penicillins. There are several groups of penicillins. 1) Penicillin G effectively destroys gram-positive flora, but does not resist microbial p-lactamase. 2) Methicillin and nafcillin have unique resistance to p-lactamase, but their bactericidal effect against gram-positive microbes is lower. 3) Ampicillin, carbenicillin and ticarcillin have the widest spectrum of action compared to other penicillins and affect both gram-positive and gram-negative microorganisms. They are, however, unstable against β-lactamase. 4) Penicillin V and cloxacillin are oral forms of penicillin. 5) Mezlocillin and piperacillin are new extended-spectrum penicillins with more pronounced activity against gram-negative microbes. These drugs are effective against Pseudomonas, Serratia and Klebsiella.

Cephalosporins are classified as penicillins, which also have a bactericidal effect. Instead of a 6-aminopenicillanic acid core, they have a 7-aminocephalosporanic acid core and comprise a number of generations, depending on their extended activity against gram-negative bacteria. First-generation cephalosporins are quite effective against Gram-positive bacteria, but have little effect on anaerobic bacteria and are only moderately effective against Gram-negative bacteria. These drugs, however, are much cheaper than the next generation of cephalosporins and are widely used in clinical practice. Second generation cephalosporins are more effective against gram-negative and anaerobic bacteria. They are particularly effective against Bacteroides fragilis. A number of antibiotics representing the second generation of cephalosporins are quite effective for the treatment of intra-abdominal purulent infection, especially in combination with aminoglycosides. The third generation of cephalosporins has an even wider spectrum of action against gram-negative bacteria. They are especially useful for the treatment of nosocomial infections. These drugs are highly resistant to β-lactamase. Their disadvantage is less effectiveness against anaerobes and staphylococci. In addition, they are relatively expensive.

Erythromycin is a macrocyclic lactone. It is effective against gram-positive bacteria. Its mechanism of action is more bacteriostatic than bactericidal. It affects bacteria, inhibiting protein synthesis in them. Erythromycin, intended for internal use intestinal use generally well tolerated, but may cause some gastrointestinal upset. This form of the drug is used for intestinal antiseptics. Erythromycin is the drug of choice for the treatment of mycoplasma infection and Legionnaires' disease.

Tetracyclines are also classified as bacteriostatic drugs. They are represented by broad-spectrum oral antibiotics that are effective against treponemas, mycobacteria, chlamydia and rickettsia. The use of tetracyclines should be avoided in children and patients with renal failure.

Levomycetin (chloramphenicol) is a broad-spectrum antibiotic with a bacteriostatic effect. It is used to treat typhoid fever, salmonellosis, and infections (including those causing meningitis) with pathogens resistant to penicillin. Side effects may manifest as hypoplastic anemia, which, fortunately, is rare. Circulatory collapse has also been described as a side effect in premature infants.

Aminoglycosides are bactericidal antibiotics that are equally effective against both gram-positive and gram-negative microflora; inhibit protein synthesis by attaching to messenger RNA. They, however, have side effects in the form of nephrotoxicity and ototoxicity. When using these antibiotics, serum creatinine levels and clearance should be monitored. It has been established that aminoglycosides are characterized by synergism with p-lactam antibiotics, such as cephalosporin or carbenicillin, against Klebsiella and Pseudomonas, respectively. Aminoglycosides are considered the most valuable drugs for the treatment of life-threatening infectious complications caused by intestinal gram-negative bacteria. Resistant strains of various gram-negative bacteria are developing against these antibiotics. Amikacin and netilmicin are considered reserve antibiotics for the treatment of severe nosocomial infections caused by gram-negative bacteria. :

Polymyxins are drugs of a polypeptide nature that are effective against Pseudomonas aeruginosa. They must be administered parenterally. Due to toxicity such as paresthesia, dizziness, kidney damage, or possible sudden stop breathing, these drugs are currently used to a limited extent.

Lincosamides, especially clindamycin, act primarily against anaerobes. A good effect from the use of these drugs is also observed in the treatment of gram-positive infections in the lungs. The main side effect is the development of pseudomembranous colitis, which manifests itself as bloody diarrhea; associated with the necrotizing effect of the toxin produced by Clostridium difficile. Cl. difficile is resistant to the action of clindamycin and becomes the dominant intestinal microflora when this antibiotic is administered orally or parenterally.

Vancomycin is bactericidal against gram-positive microflora, including staphylococci, streptococci and clostridia. It is particularly effective against multidrug-resistant gram-positive microbes. In the form for oral administration it is effectively used against C1. difficile. Its significant side effect is ototoxicity. In addition, when renal failure the time it remains in the blood is significantly extended.

Metronidazole is an antibiotic effective against amoebas, Trichomonas and Giardia. Its effect also applies to anaerobes. The drug easily crosses the blood-brain barrier and is effective in treating some brain abscesses. Metronidazole is an alternative to vancomycin in the control of Cl. difficile.

Imipenem (syn. tienam) is a carbapenem that has the widest antibacterial spectrum of action among other β-lactam antibiotics. The drug is prescribed in combination with cilastatin, which inhibits the metabolism of imipenem in the renal tubules and prevents the occurrence of nephrotoxic substances. Imipenem can be used alone to treat mixed bacterial infections that would otherwise require a combination of multiple antibiotics.

Quinolones are a family of antibiotics that have a bactericidal effect, realized through inhibition of DNA synthesis only in bacterial cells. They are effective against gram-negative bacilli and gram-positive bacteria, but poorly inhibit the growth of anaerobes. Ciprofloxin is one of the most used drugs in this group. It is especially effective in the treatment of pneumonia, infections of the urinary tract, skin and subcutaneous tissue.

ANTIFUNGAL DRUGS

Amphotericin B is the only antifungal drug that is effective against systemic mycoses. Amphotericin B changes the permeability of the fungal cytolemma, which causes cytolysis. The drug can be administered intravenously or locally. It is poorly absorbed from the gastrointestinal tract. Toxic side effects include fever, chills, nausea, vomiting and headache. Nephrotoxic effects with impaired renal function appear only with long-term continuous use.

Griseofulvin is a fungicidal drug for topical and oral use. It is used to treat superficial mycoses of the skin and nails. Long-term treatment with this drug is well tolerated by patients.

Nystatin also changes the permeability of the fungal cytolemma and has a fungistatic effect. It is not absorbed from the gastrointestinal tract. Nystatin is usually used for the prevention and treatment of gastrointestinal candidiasis, which develops secondarily as a complication of treatment with broad-spectrum antibiotics.

Flucytosine inhibits synthetic processes in the nuclei of fungal cells. It is well absorbed from the gastrointestinal tract and has low toxicity. Flucytosine is used for cryptococcosis and candidiasis, often in combination with amphotericin B.

Fluconazole improves ergosterol synthesis in fungal cells. The drug is excreted in the urine and easily penetrates into the cerebrospinal fluid.

SULPHANYLAMES

These were the first antimicrobial drugs. They have a bacteriostatic effect and are especially widely used for urinary tract infections caused by E. coli. In addition, sulfonamide derivatives are used for topical treatment of severe burn wounds. The activity of these drugs is suppressed by pus, which is rich in amino acids and purines, which is associated with the breakdown of proteins and nucleic acids. The products of this breakdown contribute to the inactivation of sulfonamides.

Sulfisoxazole and sulfamethoxazole are used to treat urinary tract infections. Mafenide is a cream for the treatment of burn wounds. Pain from tissue necrosis is a significant side effect of treatment with these drugs. Sulfamethoxazole in combination with trimethoprim has a good effect against urinary tract infections, bronchitis and pneumonia caused by Pneumocystis carinii. The drug is also successfully used against resistant strains of salmonella.

Side effects during antibiotic therapy can be classified into three main groups: allergic, toxic and associated with the chemotherapeutic effect of antibiotics. Allergic reactions are common to many antibiotics. Their occurrence does not depend on the dose, but they intensify with a repeated course and increasing doses. Life-threatening allergic reactions include anaphylactic shock, angioedema of the larynx, to non-life-threatening ones - itching, urticaria, conjunctivitis, rhinitis, etc. Allergic reactions most often develop with the use of penicillins, especially parenteral and local. Particular attention is required when prescribing long-acting antibiotics. Allergic phenomena are especially common in patients with hypersensitivity to other medications.

Toxic phenomena during antibiotic therapy are observed much more often than allergic ones; their severity is determined by the dose of the administered drug, route of administration, interaction with other drugs, and the patient’s condition. The rational use of antibiotics involves choosing not only the most active, but also the least toxic drug in harmless doses. Particular attention should be paid to newborns and young children, the elderly (due to age-related disorders of metabolic processes, water and electrolyte metabolism). Neurotoxic phenomena are associated with the possibility of damage to the auditory nerves by certain antibiotics (monomycin, kanamycin, streptomycin, florimycin, ristomycin), the effect on vestibular apparatus(streptomycin, florimycin, kanamycin, neomycin, gentamicin). Some antibiotics can also cause other neurotoxic effects (damage to optic nerve, polyneuritis, headache, neuromuscular blockade). The antibiotic should be administered intragiombally with caution due to the possibility of direct neurotoxicity.

Nephrotoxic phenomena are observed with the use of various groups of antibiotics: polymyxins, amphotericin A, aminoglycosides, griseofulvin, ristomycin, some penicillins (methicillin) and cephalosporins (cephaloridine). Patients with impaired renal excretory function are particularly susceptible to nephrotoxic complications. To prevent complications, it is necessary to choose an antibiotic, dose and regimen of its use in accordance with kidney function under constant control drug concentrations in urine and blood.

The toxic effect of antibiotics on the gastrointestinal tract is associated with a locally irritating effect on the mucous membranes and manifests itself in the form of nausea, diarrhea, vomiting, anorexia, abdominal pain, etc. Inhibition of hematopoiesis is sometimes observed up to hypo- and aplastic anemia with the use of chloramphenicol and amphotericin B; hemolytic anemia develop when using chloramphenicol. Embryotoxic effects can be observed when pregnant women are treated with streptomycin, kanamycin, neomycin, tetracycline; therefore, the use of potentially toxic antibiotics is contraindicated in pregnant women.

Side effects associated with the antimicrobial effect of antibiotics are expressed in the development of superinfection and nosocomial infections, dysbiosis and the impact on the immune system of patients. Immune suppression is characteristic of antitumor antibiotics. Some antibacterial antibiotics, for example erythromycin, lincomycin, have an immunostimulating effect.

In general, the frequency and severity of side effects during antibiotic therapy are not higher, and sometimes significantly lower, than when prescribing other groups of drugs.

By following the basic principles of rational antibiotic prescription, it is possible to minimize side effects. Antibiotics should be prescribed, as a rule, when the causative agent of the disease is isolated from a given patient and its sensitivity to a number of antibiotics and chemotherapy drugs is determined. If necessary, determine the concentration of the antibiotic in the blood, urine and other body fluids to establish optimal doses, routes and schedules of administration.

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Characteristics of the main antibacterial drugs in the treatment of patients with purulent diseases and complications

The problem of treating purulent-inflammatory diseases, which is one of the most ancient in surgery, continues to remain relevant, which is determined by the prevalence of this type of pathology, long periods of treatment for patients and high mortality. The basic principles of any method of treating purulent-necrotic processes are early removal of devitalized tissue, suppression of microflora activity in the lesion, acceleration of reparative regeneration. N.N. Burdenko (1946) wrote: “The desire to remove infection has always been the task of doctors - first on the basis of empirical thinking, and then scientifically. Bacteriological agents played a big role in both periods.” Bacteriostatic antibiotics stop the proliferation of bacteria, while bactericidal antibiotics kill the microbial cell. Bacteriostatic antibiotics include tetracyclines, chloramphenicol, some macrolides and lincosamines, and bactericidal antibiotics include penicillins, cephalosporins, aminoglycosides, fluoroquinolones, modern macrolides, rifampicin, vancomycin. When prescribing combination antibiotic therapy, the combination of agents with bactericidal and bacteriostatic activity is considered inappropriate. It is undesirable to use bacteriostatics that stop the proliferation of bacteria in patients with reduced immunity (severe infections, immunosuppressive therapy, sepsis), on whose condition the final destruction of the microbial cell depends.

Beta-lactam antibiotics (containing a beta-lactam ring) have a bactericidal effect by interfering with the synthesis of the bacterial cell wall.

Natural penicillins are the drugs of choice for pyogenic streptococcal and clostridial infections (as well as in the treatment of actinomycosis and syphilis) and remain active against anaerobic and gram-negative aerobic cocci, fusobacteria and bacteroides (with the exception of B. fragilis). In medium and high doses in combination with aminoglycosides, they are effective against enterococcal infections. Natural penicillins have lost activity against staphylococci, in most cases (60-90%) producing enzymes (beta-lactamases) that destroy penicillin antibiotics.

Penicillins are excreted mainly in the urine through the renal tubules (80-90%) and by glomerular filtration (10-20%) both in biologically active form (50-70%) and in the form of metabolites. Depending on the severity of the infection, average daily doses of benzylpenicillin can range from 8-12 million to 18-24 million units, reaching 30-60 million units in the treatment of gas gangrene. Phenoxymethylpenicillin, intended for oral administration, is used for mild infection(usually in outpatient practice) and maintenance therapy after a course of treatment with benzylpenicillin. Penicillins resistant to penicillinases (semi-synthetic penicillins) are rightfully considered the most effective antibiotics in the treatment of staphylococcal infection in patients who are not allergic to penicillins. They are quite effective against streptococci and are somewhat inferior to benzylpenicillin in activity against anaerobes; excreted in urine and bile. Methicillin has limited use, as it can cause interstitial nephritis. For infections moderate severity Oxacillin is recommended at a dose of 1 g intravenously every 4 hours; for severe infections, 9-12 g/day is prescribed.

Aminopenicillins (ampicillin, amoxicillin) belong to the second generation semisynthetic penicillins. Their spectrum of action covers many (but not all) strains of E. Coli, Proteus mirabilis, Salmonella, Shigella, H. Influenzae, Moraxella spp. The drugs are active against penicillinase-producing staphylococci, but in combination with beta-lactamase inhibitors (clavulanic acid, sulbactam), complex drugs do not have this drawback; accumulate in urine and bile and do not have a nephrotoxic effect.

Carboxypenicillins (carbenicillin, ticarcillin) and ureidopenicillins (azlocillin, mezlocillin, piperaillin) belong to the third and fourth generations of semisynthetic penicillins, are active against gram-positive and gram-negative bacteria, as well as against Pseudomonas aeruginosa and bacteroides. For Pseudomonas aeruginosa infection, it is advisable to combine these antibiotics with gentamicin (synergistic action), but solutions of the two drugs cannot be mixed, as their inactivation is possible.

Combined semisynthetic penicillins: ampicillin/sulbactam, amoxicillin/clavulanic acid, ticarcillin/clavulanic acid (timentin) are resistant to beta-lactamases and are active against beta-lactamase-producing strains of staphylococcus, enterobacteria and other gram-negative pathogens. For the treatment of severe infections, it is not recommended to use semisynthetic penicillins as monotherapy. Excreted by the kidneys (80-85%) and liver (15-20%).

Monobactams occupy a special place among beta-lactam antibiotics, since their activity extends only to gram-negative bacteria except Acinetobacter, Pseudomonas cepacia, Pseudomonas maltopillia, including beta-lactamase-producing strains. Aztreonam is ineffective against anaerobic infections and has almost no effect on gram-positive aerobes. It can be used for infections of soft tissues, bones and joints, peritonitis, and sepsis. Due to its low toxicity, this antibiotic is often used instead of aminoglycosides in patients with impaired renal function and in elderly patients.

Carbapenems - imepenem (Tienam), melopinem (Meronem) also belong to the group of new beta-lactam antibiotics, resistant to beta-lactamases, and have the widest spectrum of antibacterial activity, suppressing up to 90% of all aerobic and anaerobic microorganisms. They are ineffective against methicillin-resistant staphylococci, but are the drugs of choice in the treatment of peritonitis, pancreatic necrosis and other severe hospital infections caused by Acinetobacter spp. and P. aeruginosa. Cephalosporins have a wide spectrum of action and pronounced activity against penicillinase-producing staphylococci. First generation cephalosporins (cefazolin, cephalogin, cephalexin, etc.) are more active against gram-positive bacteria. Second generation cephalosporins (cefuroxime, cefoxigin, cefamandole, cefacmor, cefmetazole, etc.) additionally affect gram-negative pathogens (with the exception of Prseudomonas spp. Acinetobacter spp.), and cefotetam, cefmetazole are also effective against anaerobes (especially Bacteroidesfragilis), which expands their use for mixed aerobic-anaerobic infections. Third generation cephalosporins (cefotaxime, ceftazime, cefoperazone, ceftriaxone, etc.) are distinguished by even more pronounced activity against gram-negative flora, including P. aeruginosa (ceftazidime, cefoperazone), and are 2-4 times less effective against staphylococcal monoinfection. Fourth generation cephalosporins (cefepime, cefpirome) have not yet found adequate use in domestic practice, although their spectrum of activity against gram-negative flora is comparable to carbapenems.

Aminoglycosins are also broad-spectrum antibiotics with bactericidal activity against gram-positive cocci (although it is wrong to start treatment of staphylococcal infections with them) and many gram-negative bacteria (Enterobacteriaceae, Pseudomonas spp., Acinetobacter spp.), which allows their use, in particular, in combination with beta-lactam antibiotics for the treatment of severe nosocomial infections. Aminoglycosides are divided into first generation (streptomycin, kanamycin, monomycin, neomycin), second (gentamicin, tobramycin, netilmicin), third (amikacin, sisomycin).

Aminoglycosides

The first generation has practically lost its importance in medical practice(with the exception of streptomycin in phthisiopulmonology and in the treatment of enterococcal endocarditis in combination with benzylpenicillin, as well as oral neomycin during preoperative bowel preparation). Aminoglycosides penetrate poorly through the blood-brain barrier, into bile, and bone tissue; Insufficient concentrations are created in pleural, pericardial, ascitic fluid, bronchial secretions, and sputum; aminoglycosides are excreted in the urine. Observations recent years indicate that a single injection of aminoglycosides into daily dose It is preferable to multiple injections due to a more pronounced bactericidal effect on the pathogen and a lower frequency of side effects.

Macrolides [erythromycin, azithromycin (sumamed), roxithromycin (rulid), midakamycin (macropen), etc.] are classified as bacteriostatic drugs, but in high doses and low contamination by microorganisms they act bactericidal. Streptococci, staphylococci and gram-negative anaerobes (except B. fragilis) are sensitive to them, and in mild and moderate severe course Staphylococcal infections, they are the drugs of choice in patients with allergies to penicillins and cephalosporins. Microflora resistance to erythromycin quickly develops.

Tetracyclines act bacteriostatically on many gram-positive and gram-negative microorganisms, but as a result of rapidly developing resistance and poor tolerability, they are practically not used in the treatment of inpatients. This group includes tetracycline, oxytetracycline and semisynthetic tetracyclines - doxycycline (vibramycin), minocycline. Fluoroquinolones [ciprofloxacin, lomofloxacin, oloxacin (Tarivid), pefloxacin, slarfloxacin, etc.] destroy the cells of many strains of gram-negative bacteria (including P. aeruginosa), staphylococci and selectively streptococci, have no effect on anaerobes, fecal enterococcus and individual species Pseudomonas. They are well absorbed when taken orally, which ensures the achievement of therapeutic concentrations in biological fluids and tissues, but in case of severe infection, infusion administration of the drug is preferable. Excreted in urine, where high levels of antibiotics are achieved. Staphylococcus and intracellular bacteria, Mycobacterium tuberculosis are highly sensitive to fluoroquinolone. Lincosamines - lincomycin, clindamycin - alternative antibiotics for allergies to penicillins and cephalosporins; active against streptococci, most strains of S. aureus, gram-positive and gram-negative anaerobes; metabolized in the liver. Relative contraindications- diarrhea and related inflammatory diseases intestines. Clindamycin has fewer side effects and, compared to lincomycin, is clinically more active against staphylococcal infections. Glycopeptides (vancomycin, teicoplakin) are the most effective infusion antibiotics against methicillin-resistant staphylococci and are highly effective in the treatment of enterococcal infections; do not act on gram-negative bacteria and anaerobes. Polymyxins [polymyxin (polyfax), colistin (polymyxin E)] are used for the treatment of Pseudomonas aeruginosa infection due to the high sensitivity of pseudomonas to these drugs. Rifampicin is a traditional anti-tuberculosis drug, which in combination with other antibiotics is successfully used to treat streptococcal and staphylococcal infections, but is inferior to vancomycin in anti-staphylococcal activity. A significant drawback of the drug is the rapidly developing resistance of the microbial flora to it. Levomycetin (chloramphenicol) is used to treat typhus, dysentery, tularemia, and meningococcal infections. For purulent-inflammatory diseases it is ineffective due to the high resistance of the microbial flora, but all gram-negative non-clostridial bacilli are sensitive to chloramphenicol (Vasina T.A., 1996). Indications for the use of chloramphenicol in purulent surgery are limited to cases of anaerobic non-spore-forming infection, when it can be used in combination with aminoglycosides. Antifungal drugs. This group includes nystatin, levorin, amphotericin B, ketoconazole, fluconazole. In the treatment of purulent-inflammatory diseases, sulfonamide drugs are effective, having a bactericidal effect on gram-positive and gram-negative flora. The most important are sulfonamides with long-term (sulfapyridazine, sulfadimethoxine) or extra-long-term (sulfalene) action. The maximum concentration in the blood of long-acting drugs after a single dose decreases by 50% after 24-48 hours, and 50% of the drug is excreted in the urine after 24-56 hours. A decrease in the therapeutic concentration of sulfalene by 50% occurs after 65 hours, and the bacteriostatic concentration remains in for 7 days. The drugs are also used in combination with antibiotics in the treatment of purulent diseases of soft tissues, glandular organs, osteomyelitis, and purulent wounds. Sulfapyridazine and sulfapyridazine sodium are prescribed orally according to the scheme, the course of treatment is 5-7 days. Sulfapyridazine sodium in the form of a 3-10% solution is used to wash wounds; A 10% solution of the drug in polyvinyl alcohol is used topically to sanitize purulent lesions. Sulfalene is prescribed orally, administered intravenously in the same doses (special ampoules of 0.5 g). Sulfonamide preparations in combination with diaminopyrimidine derivatives (Bactrim, Biseptol) have an active antibacterial effect. Of the nitrofuran derivatives, for the treatment of purulent-inflammatory diseases, potassium furagin is used intravenously, 300-500 ml (0.3-0.5 g) of a 0.1% solution, used for a course of 3-7 infusions. Used locally for the rehabilitation of purulent cavities.

Chemical antiseptics are used topically, they allow you to create high concentration directly in the hearth purulent inflammation. The drugs are more resistant to the effects of inflammation or necrosis products than antibiotics. The antibacterial activity of antiseptics is increased by physical factors - drainage, ultrasound, laser energy, plasma; necrotic - proteolytic enzymes, sodium hypochlorite; biological agents (bacteriophages), etc.

Antiseptics have a wide antibacterial spectrum of action and provide a bactericidal or bacteriostatic effect. The resistance of microorganisms to them is relatively low, the distribution of these forms is small. The drugs are poorly absorbed, but are stable when long-term storage and rarely exhibit side effects (irritant or allergic). Most effective antiseptics used in surgical practice are surfactants: chlorhexidine bigluconate. Working concentrations 0.02-0.5%; catapol, working concentration 0.1-0.4%; miramistin - at a concentration of 0.01%; The spectrum of action of surfactants is aerobes, anaerobes, fungi.

Iodide preparations:

Povidone-iodine (iodopyrone, betadine). Working concentration - 0.1-1.0%; Iodinol - ready solution. The spectrum of action of iodine preparations is aerobes, anaerobes, fungi.

Derivatives of quinoline and quinoxaline:

Rivanol (ethacridalactate) - 0.05-0.2%; dioxidine - 0.5-1.0%. The drugs act on aerobic and anaerobic flora.

Nitrofuran derivatives:

Furacilin 1:5000; furagin K (furazidim) - 1:13,000. Spectrum of action - aerobes and anaerobes.

Electrochemical solutions:

Sodium ripochlorite 0.03-0.12%. Spectrum of action: aerobes, anaerobes, fungi. The listed drugs give a pronounced antibacterial, mainly bactericidal effect when local application in the treatment of wounds (washing, wetting tampons), sanitation of mucous membranes. Similar drugs used to treat surgeon's hands. The drugs are used for intracavitary administration, for empyema, but for the sanitation of purulent cavities large sizes , the serous membrane of which has a pronounced sorption capacity (peritoneum), it is possible to use only drugs suitable for intravenous administration (potassium furagin, dioxidine, sodium hypochlorite). Flow-through, flow-wash drainage, and peritoneal dialysis make it possible to avoid the general toxic effect of drugs due to their absorption into the blood. The pyogenic flora does not have absolute sensitivity to antiseptics, although it is quite sensitive to some of them. So, according to G.E. Afinogenov and M.V. Krasnov (2003), S. aureus is sensitive to chlorhexidine, dioxidine, catapol, and iodopyrine in 69-97% of strains. The highest sensitivity was noted for catapol (97%). E. coli is most sensitive to dioxidine and catapol (78%), and to chlorhexidine and iodopyrone in 55-58%. Proteus spp. most sensitive to chlorhexidine and dioxidine (90 and 84%), and to iodopyrone - only 35%, to catapol - 40%. Ps. aeruginosa is most sensitive to dioxidine (92%), chlorhexidine, iodopyrone (52-62%). The effectiveness of antiseptics increases when they are used together or when combined with physical antiseptics. The activity of antibiotics is determined by their accumulation in the lesion. The concentration of the drug should be quite high, and the exposure should be long. The action of the antibiotic is also characterized by the “antibacterial titer”, i.e. the ratio of the concentration of the antibiotic in the blood (tissues) and its minimum concentration that has an antibacterial effect. In practical work, it is sufficient to determine the concentration of the antibiotic in the blood. Ideally, the concentration of the drug in the lesion should provide a bactericidal effect. As a rule, there is a certain relationship between the concentrations of antibiotics in the blood and tissues, which is determined by the overall diffusion ability of the drug. Drugs such as chloramphenicol, erythromycin, and oleandomycin have high diffusion ability. For tetracycline it is 50%, for aminoglycosides - about 30%, for penicillins - 10-30%. Thus, with a concentration of erythromycin in the blood equal to 1-3 μg/ml, its content in the lungs is 30%, in the bones - up to 15%. When the concentration of penicillin in the blood is 0.5-3 units in the abdominal cavity it reaches 30-50%, in the pleural cavity - 20-30%, in the bones - 30-50%. The accumulation of the drug at the site of inflammation is also determined by the tropism of the antibiotics to organs and tissues. Penicillins, macrolides, tetracyclines, aminoglycosides, monobactams, and fluoroquinolones have a high affinity for lung tissue. An average degree of tropism is noted for lincosamines and fusidine. Rifampicin and monobactams exhibit high tropism for the pleura and the ability to accumulate in pleural exudate; fluoroquinolones, tetracyclines, fusidine, and macrolides have moderate tropism; polymyxins and lincosamines have low tropism. Fluoroquinolones have an average affinity for mediastinal tissue. High tropism for bone tissue exhibit lincosamines, cephalosporins, fusidine, fluoroquinolones; medium - tetracyclines (monobactams have affinity for the bone tissue of the sternum, fusidine - for cartilage tissue), low - penicillins, macrolides. High tropism for muscle tissue in cephalosporins, macrolides, monobactams, fluoroquinolones; average - for lincosamines, rifampicin, low - for macrolides. To lymphoid tissue, lymph nodes Macrolides and fluoroquinolones exhibit high tropism. Fusidine, which is excreted in milk, exhibits moderate affinity for breast tissue. Penicillins have a high affinity for liver tissue and bile. fluoroquinolones, macrolides, intermediate - aminoglycosides, cephalosporins, macrolides. Carbopenems show a high affinity for pancreatic tissue, while aminoglycosides, fluoroquinolones, and rifampicin show moderate affinity. VC. Gostishchev

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Ecology DIRECTORY

Based on the nature of their action, antibiotics are divided into bactericidal and bacteriostatic. The bactericidal effect is characterized by the fact that under the influence of the antibiotic, the death of microorganisms occurs. Achieving a bactericidal effect is especially important when treating weakened patients, as well as in cases of such severe illness infectious diseases, such as general blood infection (sepsis), endocarditis, etc., when the body is not able to fight the infection on its own. Antibiotics such as various penicillins, streptomycin, neo-mycin, kanamycin, vancomycin, polymyxin have a bactericidal effect. [...]

With a bacteriostatic effect, the death of microorganisms does not occur, only the cessation of their growth and reproduction is observed. When the antibiotic is removed from the environment, microorganisms can develop again. In most cases, when treating infectious diseases, the bacteriostatic effect of antibiotics in combination with the body’s defense mechanisms ensures the patient’s recovery.[...]

It is interesting to note that penicillinase has now found practical use as an antidote - a drug that removes harmful effect penicillin, when it causes severe allergic reactions that threaten the patient’s life.[...]

Microorganisms that are resistant to one antibiotic are simultaneously resistant to other antibiotic substances that are similar to the first in their mechanism of action. This phenomenon is called cross-resistance. For example, microorganisms that become resistant to tetracycline simultaneously become resistant to chlortetracycline and oxytetracycline.[...]

All these facts indicate that for successful treatment Before prescribing antibiotics, one should determine the antibiotic resistance of pathogenic microbes, and also try to overcome the drug resistance of microbes.[...]

There are many conflicting theories that try to explain the origin of resistance to medicinal substances. They mainly concern questions about the role of mutations and adaptation in the acquisition of resistance. Apparently, in the process of developing resistance to drugs, including antibiotics, both adaptive and mutational changes play a certain role.[...]

Nowadays, when antibiotics are widely used, resistant to antibiotic drugs forms of microorganisms are very common.[...]

Antibiotics are a huge group of bactericidal drugs, each of which is characterized by its own spectrum of action, indications for use and the presence of certain consequences

Antibiotics are substances that can inhibit the growth of microorganisms or destroy them. According to the GOST definition, antibiotics include substances of plant, animal or microbial origin. Currently, this definition is somewhat outdated, since a huge number of synthetic drugs have been created, but natural antibiotics served as the prototype for their creation.

The history of antimicrobial drugs begins in 1928, when A. Fleming first discovered penicillin. This substance was discovered, and not created, since it has always existed in nature. It is produced in living nature microscopic fungi genus Penicillium, protecting itself from other microorganisms.

In less than 100 years, more than a hundred different antibacterial drugs have been created. Some of them are already outdated and are not used in treatment, and some are just being introduced into clinical practice.

How do antibiotics work?

All antibacterial drugs can be divided into two large groups according to their effect on microorganisms:

• bactericidal– directly cause the death of microbes;
• bacteriostatic– prevent the proliferation of microorganisms. Unable to grow and reproduce, bacteria are destroyed by the immune system of a sick person.

Antibiotics exert their effects in many ways: some of them interfere with the synthesis of microbial nucleic acids; others interfere with the synthesis of bacterial cell walls, others disrupt protein synthesis, and others block the functions of respiratory enzymes.

Antibiotic groups

Despite the diversity of this group of drugs, all of them can be classified into several main types. This classification is based on chemical structure - drugs from the same group have a similar chemical formula, differing from each other in the presence or absence of certain molecular fragments.

The classification of antibiotics implies the presence of groups:

1. Penicillin derivatives. This includes all drugs created on the basis of the very first antibiotic. In this group, the following subgroups or generations of penicillin drugs are distinguished:

• Natural benzylpenicillin, which is synthesized by fungi, and semi synthetic drugs: methicillin, nafcillin.
• Synthetic drugs: carbpenicillin and ticarcillin, which have a wider spectrum of action.
• Mecillam and azlocillin, which have an even wider spectrum of action.

1. Cephalosporins- Closest relatives of penicillins. The very first antibiotic of this group, cefazolin C, is produced by fungi of the genus Cephalosporium. Most drugs in this group have a bactericidal effect, that is, they kill microorganisms. There are several generations of cephalosporins:

• I generation: cefazolin, cephalexin, cefradine, etc.
• II generation: cefsulodin, cefamandole, cefuroxime.
• III generation: cefotaxime, ceftazidime, cefodizime.
• IV generation: cefpirom.
• V generation: ceftolozane, ceftopibrol.

The differences between the different groups are mainly in their effectiveness - later generations have a greater spectrum of action and are more effective. 1st and 2nd generation cephalosporins are now used extremely rarely in clinical practice, most of them are not even produced.

1. – drugs with a complex chemical structure that have a bacteriostatic effect on a wide range of microbes. Representatives: azithromycin, rovamycin, josamycin, leucomycin and a number of others. Macrolides are considered one of the safest antibacterial drugs - they can even be used by pregnant women. Azalides and ketolides are varieties of macorlides that have differences in the structure of the active molecules.

Another advantage of this group of drugs is that they are able to penetrate the cells of the human body, which makes them effective in the treatment of intracellular infections:,.

1. Aminoglycosides. Representatives: gentamicin, amikacin, kanamycin. Effective against a large number of aerobic gram-negative microorganisms. These drugs are considered the most toxic and can lead to quite serious complications. Used to treat genitourinary tract infections.
2. Tetracyclines. These are mainly semi-synthetic and synthetic drugs, which include: tetracycline, doxycycline, minocycline. Effective against many bacteria. The disadvantage of these drugs is cross-resistance, that is, microorganisms that have developed resistance to one drug will be insensitive to others from this group.
3. Fluoroquinolones. These are completely synthetic drugs that do not have their natural counterpart. All drugs in this group are divided into first generation (pefloxacin, ciprofloxacin, norfloxacin) and second generation (levofloxacin, moxifloxacin). They are most often used to treat infections of the ENT organs (,) and respiratory tract ( , ).
4. Lincosamides. This group includes the natural antibiotic lincomycin and its derivative clindamycin. They have both bacteriostatic and bactericidal action, the effect depends on the concentration.
5. Carbapenems. These are one of the most modern antibiotics acting on a large number of microorganisms. Drugs in this group belong to reserve antibiotics, that is, they are used in the most difficult cases when other medications are ineffective. Representatives: imipenem, meropenem, ertapenem.
6. Polymyxins. These are highly specialized drugs used to treat infections caused by. Polymyxins include polymyxin M and B. The disadvantage of these drugs is their toxic effect on the nervous system and kidneys.
7. Antituberculosis drugs. This is a separate group of drugs that have a pronounced effect on. These include rifampicin, isoniazid and PAS. Other antibiotics are also used to treat tuberculosis, but only if resistance to the drugs mentioned has developed.
8. Antifungal agents. This group includes drugs used to treat mycoses - fungal infections: amphothirecin B, nystatin, fluconazole.

Methods of using antibiotics

Antibacterial drugs are available in different forms: tablets, powder from which an injection solution is prepared, ointments, drops, spray, syrup, suppositories. The main uses of antibiotics:

1. Oral- oral administration. You can take the medicine in the form of a tablet, capsule, syrup or powder. The frequency of administration depends on the type of antibiotic, for example, azithromycin is taken once a day, and tetracycline is taken 4 times a day. For each type of antibiotic there are recommendations that indicate when it should be taken - before, during or after meals. The effectiveness of treatment and the severity of side effects depend on this. Antibiotics are sometimes prescribed to young children in syrup form - it is easier for children to drink the liquid than to swallow a tablet or capsule. In addition, the syrup can be sweetened to eliminate the unpleasant or bitter taste of the medicine itself.
2. Injectable– in the form of intramuscular or intravenous injections. With this method, the drug reaches the site of infection faster and is more active. The disadvantage of this method of administration is that the injection is painful. Injections are used for moderate and severe diseases.

Important:Only a nurse should give injections in a clinic or hospital setting! It is strictly not recommended to inject antibiotics at home.

1. Local– applying ointments or creams directly to the site of infection. This method of drug delivery is mainly used for skin infections - erysipelas, as well as in ophthalmology - for infectious lesion eyes, for example, tetracycline ointment for conjunctivitis.

The route of administration is determined only by the doctor. In this case, many factors are taken into account: the absorption of the drug in the gastrointestinal tract, the state of the digestive system as a whole (in some diseases, the absorption rate decreases and the effectiveness of treatment decreases). Some drugs can only be administered one way.

When injecting, you need to know how to dissolve the powder. For example, Abactal can only be diluted with glucose, since when sodium chloride is used it is destroyed, which means the treatment will be ineffective.

Antibiotic sensitivity

Any organism sooner or later gets used to the harshest conditions. This statement is also true in relation to microorganisms - in response to prolonged exposure to antibiotics, microbes develop resistance to them. The concept of sensitivity to antibiotics was introduced into medical practice - the effectiveness with which a particular drug affects the pathogen.

Any prescription of antibiotics should be based on knowledge of the sensitivity of the pathogen. Ideally, before prescribing a drug, the doctor should conduct a sensitivity test and prescribe the most effective drug. But the time required to carry out such an analysis is, in the best case, several days, and during this time the infection can lead to the most disastrous result.

Therefore, in case of infection with an unknown pathogen, doctors prescribe drugs empirically - taking into account the most likely pathogen, with knowledge of the epidemiological situation in a particular region and medical institution. For this purpose, broad-spectrum antibiotics are used.

After performing a sensitivity test, the doctor has the opportunity to change the drug to a more effective one. The drug can be replaced if there is no effect from treatment for 3-5 days.

Etiotropic (targeted) prescription of antibiotics is more effective. At the same time, it becomes clear what caused the disease - using bacteriological research, the type of pathogen is established. Then the doctor selects a specific drug to which the microbe does not have resistance (resistance).

Are antibiotics always effective?

Antibiotics only act on bacteria and fungi! Bacteria are considered single-celled microorganisms. There are several thousand species of bacteria, some of which coexist quite normally with humans—more than 20 species of bacteria live in the large intestine. Some bacteria are opportunistic - they cause disease only under certain conditions, for example, when they enter an atypical habitat. For example, very often prostatitis causes coli, entering through the ascending route from the rectum.

Note: Antibiotics are completely ineffective viral diseases. Viruses are many times smaller than bacteria, and antibiotics simply do not have a point of application for their ability. That's why antibiotics have no effect on colds, since colds in 99% of cases are caused by viruses.

Antibiotics for coughs and bronchitis may be effective if they are caused by bacteria. Only a doctor can figure out what causes the disease - for this he prescribes blood tests, and, if necessary, an examination of sputum if it comes out.

Important:Prescribing antibiotics to yourself is unacceptable! This will only lead to the fact that some of the pathogens will develop resistance, and next time the disease will be much more difficult to cure.

Of course, antibiotics are effective for - this disease is exclusively bacterial in nature, caused by streptococci or staphylococci. To treat sore throat, the simplest antibiotics are used - penicillin, erythromycin. The most important thing in the treatment of angina is compliance with the frequency of dosing and the duration of treatment - at least 7 days. You should not stop taking the medicine immediately after the onset of the condition, which is usually noted on the 3-4th day. True tonsillitis should not be confused with tonsillitis, which can be of viral origin.

Note: untreated sore throat can cause acute rheumatic fever or!

Pneumonia (pneumonia) can be of both bacterial and viral origin. Bacteria cause pneumonia in 80% of cases, so even when prescribed empirically, antibiotics for pneumonia have a good effect. For viral pneumonia, antibiotics do not have a therapeutic effect, although they prevent the bacterial flora from joining the inflammatory process.

Antibiotics and alcohol

Taking alcohol and antibiotics at the same time in a short period of time does not lead to anything good. Some drugs are broken down in the liver, just like alcohol. The presence of antibiotics and alcohol in the blood puts a heavy load on the liver - it simply does not have time to neutralize ethanol. As a result, the likelihood of developing unpleasant symptoms increases: nausea, vomiting, and intestinal disorders.

Important: a number of drugs interact with alcohol at the chemical level, resulting in a direct decrease in therapeutic effect. These drugs include metronidazole, chloramphenicol, cefoperazone and a number of others. Concomitant use of alcohol and these drugs can not only reduce the therapeutic effect, but also lead to shortness of breath, seizures and death.

Of course, some antibiotics can be taken while drinking alcohol, but why risk your health? It is better to abstain from alcoholic beverages for a short time - the course of antibacterial therapy rarely exceeds 1.5-2 weeks.

Antibiotics during pregnancy

Pregnant women suffer from infectious diseases no less often than everyone else. But treating pregnant women with antibiotics is very difficult. In the body of a pregnant woman, the fetus grows and develops - the unborn child, very sensitive to many chemicals. The entry of antibiotics into the developing body can provoke the development of fetal malformations and toxic damage to the central nervous system of the fetus.

During the first trimester, it is advisable to avoid the use of antibiotics altogether. In the second and third trimesters, their use is safer, but should also be limited, if possible.

A pregnant woman cannot refuse to prescribe antibiotics for the following diseases:

• Pneumonia;
• angina;
• infected wounds;
• specific infections: brucellosis, borelliosis;
• sexually transmitted infections: , .

What antibiotics can be prescribed to a pregnant woman?

Penicillin, cephalosporin drugs, erythromycin, and josamycin have almost no effect on the fetus. Penicillin, although it passes through the placenta, does not have a negative effect on the fetus. Cephalosporin and other named drugs penetrate the placenta in extremely low concentrations and are not capable of harming the unborn child.

K conditionally safe drugs include metronidazole, gentamicin and azithromycin. They are prescribed only for health reasons, when the benefit to the woman outweighs the risk to the child. Such situations include severe pneumonia, sepsis, and other severe infections in which, without antibiotics, a woman can simply die.

Which drugs should not be prescribed during pregnancy?

The following drugs should not be used in pregnant women:

• aminoglycosides– can lead to congenital deafness (with the exception of gentamicin);
• clarithromycin, roxithromycin– in experiments they had a toxic effect on animal embryos;
• fluoroquinolones;
• tetracycline– disrupts the formation of the skeletal system and teeth;
• chloramphenicol– dangerous in late pregnancy due to inhibition of bone marrow functions in the child.

For some antibacterial drugs there is no data on negative effects on the fetus. This is explained simply - experiments are not carried out on pregnant women to determine the toxicity of drugs. Experiments on animals do not allow us to exclude all negative effects with 100% certainty, since the metabolism of drugs in humans and animals can differ significantly.

Please note that you should also stop taking antibiotics or change your plans for conception. Some drugs have a cumulative effect - they can accumulate in a woman’s body, and for some time after the end of the course of treatment they are gradually metabolized and eliminated. It is recommended to become pregnant no earlier than 2-3 weeks after finishing taking antibiotics.

Consequences of taking antibiotics

The entry of antibiotics into the human body leads not only to the destruction of pathogenic bacteria. Like all foreigners chemicals, antibiotics provide systemic action– to one degree or another affect all systems of the body.

There are several groups of side effects of antibiotics:

Allergic reactions

Almost any antibiotic can cause allergies. The severity of the reaction varies: rash on the body, Quincke's edema (angioedema), anaphylactic shock. While an allergic rash is practically harmless, anaphylactic shock can be fatal. The risk of shock is much higher with antibiotic injections, which is why injections should only be done in medical institutions - emergency care can be provided there.

Antibiotics and other antimicrobial drugs that cause cross-allergic reactions:

Toxic reactions

Antibiotics can damage many organs, but the liver is most susceptible to their effects; during antibacterial therapy, toxic hepatitis. Selected drugs have a selective toxic effect on other organs: aminoglycosides - on the hearing aid (cause deafness); tetracyclines inhibit bone growth in children.

note: The toxicity of a drug usually depends on its dose, but in case of individual intolerance, sometimes smaller doses are sufficient to produce an effect.

Effects on the gastrointestinal tract

When taking certain antibiotics, patients often complain of stomach pain, nausea, vomiting, and stool disorders (diarrhea). These reactions are most often caused by the locally irritating effect of the drugs. The specific effect of antibiotics on the intestinal flora leads to functional disorders of its activity, which is most often accompanied by diarrhea. This condition is called antibiotic-associated diarrhea, which is popularly known as dysbiosis after antibiotics.

Other side effects

Other things side effects include:

• immunosuppression;
• emergence of antibiotic-resistant strains of microorganisms;
• superinfection – a condition in which microbes resistant to a given antibiotic are activated, leading to the emergence of a new disease;
• violation of vitamin metabolism - caused by inhibition of the natural flora of the colon, which synthesizes some B vitamins;
• Jarisch-Herxheimer bacteriolysis is a reaction that occurs when using bactericidal drugs, when, as a result of the simultaneous death of a large number of bacteria, a large number of toxins are released into the blood. The reaction is clinically similar to shock.

Can antibiotics be used prophylactically?

Self-education in the field of treatment has led to the fact that many patients, especially young mothers, try to prescribe themselves (or their child) an antibiotic at the slightest sign of a cold. Antibiotics do not have a prophylactic effect - they treat the cause of the disease, that is, they eliminate microorganisms, and in their absence, only side effects of the drugs appear.

There are a limited number of situations when antibiotics are administered before clinical manifestations of infection, in order to prevent it:

• surgery– in this case, the antibiotic present in the blood and tissues prevents the development of infection. As a rule, a single dose of the drug administered 30-40 minutes before the intervention is sufficient. Sometimes even after an appendectomy postoperative period do not inject antibiotics. After “clean” surgical operations, antibiotics are not prescribed at all.
• major injuries or wounds(open fractures, soil contamination of the wound). In this case, it is absolutely obvious that an infection has entered the wound and it should be “crushed” before it manifests itself;
• emergency prevention of syphilis carried out during unprotected sexual contact with a potentially sick person, as well as among health workers who have had the blood of an infected person or other biological fluid come into contact with the mucous membrane;
• penicillin can be prescribed to children for the prevention of rheumatic fever, which is a complication of tonsillitis.

Antibiotics for children

The use of antibiotics in children is generally no different from their use in other groups of people. For young children, pediatricians most often prescribe antibiotics in syrup. This dosage form is more convenient to take and, unlike injections, is completely painless. Older children may be prescribed antibiotics in tablets and capsules. In severe cases, infections progress to parenteral route administration - injections.

Important: The main feature in the use of antibiotics in pediatrics is the dosage - children are prescribed smaller doses, since the drug is calculated in terms of per kilogram of body weight.

Antibiotics are very effective drugs, but at the same time they have a large number of side effects. In order to be cured with their help and not harm your body, they should be taken only as prescribed by a doctor.

What types of antibiotics are there? In what cases is taking antibiotics necessary and in what cases is it dangerous? The main rules of antibiotic treatment are explained by pediatrician Dr. Komarovsky:

Gudkov Roman, resuscitator