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Antibiotics are a group of drugs that can inhibit the growth and development of living cells. They are most often used to treat infectious processes caused by various strains of bacteria. The first drug was discovered in 1928 by British bacteriologist Alexander Fleming. However, some antibiotics are also prescribed for cancer pathologies, as a component of combination chemotherapy. This group of drugs has practically no effect on viruses, with the exception of some tetracyclines. In modern pharmacology, the term “antibiotics” is increasingly being replaced by “antibacterial drugs”.

They were the first to synthesize drugs from the penicillin group. They have helped to significantly reduce the mortality rate of diseases such as pneumonia, sepsis, meningitis, gangrene and syphilis. Over time, due to the active use of antibiotics, many microorganisms began to develop resistance to them. Therefore, the search for new groups of antibacterial drugs has become an important task.

Gradually, pharmaceutical companies synthesized and began to produce cephalosporins, macrolides, fluoroquinolones, tetracyclines, chloramphenicol, nitrofurans, aminoglycosides, carbapenems and other antibiotics.

Antibiotics and their classification

The main pharmacological classification of antibacterial drugs is based on their effect on microorganisms. Based on this characteristic, two groups of antibiotics are distinguished:

• bactericidal - drugs cause the death and lysis of microorganisms. This effect is due to the ability of antibiotics to inhibit membrane synthesis or suppress the production of DNA components. Penicillins, cephalosporins, fluoroquinolones, carbapenems, monobactams, glycopeptides and fosfomycin have this property.
• bacteriostatic - antibiotics can inhibit the synthesis of proteins by microbial cells, which makes their reproduction impossible. As a result, further development of the pathological process is limited. This action is typical for tetracyclines, macrolides, aminoglycosides, lincosamines and aminoglycosides.

Based on the spectrum of action, two groups of antibiotics are also distinguished:

• with broad - the drug can be used to treat pathologies caused by a large number of microorganisms;
• with a narrow one - the medication affects individual strains and types of bacteria.

There is also a classification of antibacterial drugs according to their origin:

• natural - obtained from living organisms;
• semisynthetic antibiotics are modified molecules of natural analogues;
• synthetic - they are produced completely artificially in specialized laboratories.

Description of different groups of antibiotics

Beta-lactams

Penicillins

Historically, the first group of antibacterial drugs. Has a bactericidal effect on a wide range of microorganisms. Penicillins are divided into the following groups:

• natural penicillins (synthesized under normal conditions by fungi) - benzylpenicillin, phenoxymethylpenicillin;
• semisynthetic penicillins, which are more resistant to penicillinases, which significantly expands their spectrum of action - oxacillin, methicillin medications;
• with extended action - preparations of amoxicillin, ampicillin;
• penicillins with a broad effect on microorganisms - medications mezlocillin, azlocillin.

To reduce bacterial resistance and increase the chance of success of antibiotic therapy, penicillinase inhibitors - clavulanic acid, tazobactam and sulbactam - are actively added to penicillins. This is how the drugs “Augmentin”, “Tazocim”, “Tazrobida” and others appeared.

These medications are used for infections of the respiratory (bronchitis, sinusitis, pneumonia, pharyngitis, laryngitis), genitourinary (cystitis, urethritis, prostatitis, gonorrhea), digestive (cholecystitis, dysentery) systems, syphilis and skin lesions. The most common side effects are allergic reactions (urticaria, anaphylactic shock, angioedema).

Penicillins are also the safest drugs for pregnant women and infants.

Cephalosporins

This group of antibiotics has a bactericidal effect on a large number of microorganisms. Today the following generations of cephalosporins are distinguished:

The vast majority of these medications exist only in injection form, so they are used mainly in clinics. Cephalosporins are the most popular antibacterial agents for use in hospitals.

These drugs are used to treat a huge number of diseases: pneumonia, meningitis, generalized infections, pyelonephritis, cystitis, inflammation of bones, soft tissues, lymphangitis and other pathologies. Hypersensitivity is common with the use of cephalosporins. Sometimes a transient decrease in creatinine clearance, muscle pain, cough, and increased bleeding (due to a decrease in vitamin K) are observed.

Carbapenems

They are a fairly new group of antibiotics. Like other beta-lactams, carbapenems have a bactericidal effect. A huge number of different strains of bacteria remain sensitive to this group of medications. Carbapenems also exhibit resistance against enzymes synthesized by microorganisms. Data properties have led to them being considered rescue drugs when other antibacterial agents remain ineffective. However, their use is strictly limited due to concerns about the development of bacterial resistance. This group of drugs includes meropenem, doripenem, ertapenem, imipenem.

Carbapenems are used to treat sepsis, pneumonia, peritonitis, acute surgical pathologies of the abdominal cavity, meningitis, and endometritis. These drugs are also prescribed to patients with immunodeficiencies or due to neutropenia.

Side effects include dyspepsia, headache, thrombophlebitis, pseudomembranous colitis, convulsions and hypokalemia.

Monobactams

Monobactams act predominantly only on gram-negative flora. The clinic uses only one active substance from this group - aztreonam. Its advantages include resistance to most bacterial enzymes, which makes it the drug of choice when treatment with penicillins, cephalosporins and aminoglycosides is ineffective. Clinical guidelines recommend aztreonam for enterobacter infection. It is used only intravenously or intramuscularly.

Indications for use include sepsis, community-acquired pneumonia, peritonitis, infections of the pelvic organs, skin and musculoskeletal system. The use of aztreonam sometimes leads to the development of dyspeptic symptoms, jaundice, toxic hepatitis, headache, dizziness and allergic rash.

Macrolides

Medicines are also characterized by low toxicity, which allows them to be used during pregnancy and early childhood. They are divided into the following groups:

• natural ones, which were synthesized in the 50-60s of the last century - preparations of erythromycin, spiramycin, josamycin, midecamycin;
• prodrugs (converted to the active form after metabolism) - troleandomycin;
• semisynthetic - medications azithromycin, clarithromycin, dirithromycin, telithromycin.

Macrolides are used for many bacterial pathologies: peptic ulcer, bronchitis, pneumonia, infections of the ENT organs, dermatosis, Lyme disease, urethritis, cervicitis, erysipelas, impentigo. This group of medications should not be used for arrhythmias or renal failure.

Tetracyclines

Tetracyclines were first synthesized more than half a century ago. This group has a bacteriostatic effect against many strains of microbial flora. In high concentrations they also exhibit a bactericidal effect. A feature of tetracyclines is their ability to accumulate in bone tissue and tooth enamel.

On the one hand, this allows clinicians to actively use them in chronic osteomyelitis, and on the other hand, it disrupts the development of the skeleton in children. Therefore, they should absolutely not be used during pregnancy, lactation and under the age of 12 years. Tetracyclines, in addition to the drug of the same name, include doxycycline, oxytetracycline, minocycline and tigecycline.

They are used for various intestinal pathologies, brucellosis, leptospirosis, tularemia, actinomycosis, trachoma, Lyme disease, gonococcal infection and rickettsiosis. Contraindications also include porphyria, chronic liver diseases and individual intolerance.

Fluoroquinolones

Fluoroquinolones are a large group of antibacterial agents with a broad bactericidal effect on pathogenic microflora. All drugs are similar to nalidixic acid. The active use of fluoroquinolones began in the 70s of the last century. Today they are classified by generation:

• I - preparations of nalidixic and oxolinic acid;
• II - medications with ofloxacin, ciprofloxacin, norfloxacin, pefloxacin;
• III - levofloxacin preparations;
• IV - medications with gatifloxacin, moxifloxacin, gemifloxacin.

The latest generations of fluoroquinolones are called “respiratory”, due to their activity against microflora, which most often causes the development of pneumonia. They are also used to treat sinusitis, bronchitis, intestinal infections, prostatitis, gonorrhea, sepsis, tuberculosis and meningitis.

Among the disadvantages, it is necessary to highlight the fact that fluoroquinolones can influence the formation of the musculoskeletal system, therefore in childhood, pregnancy and lactation they can be prescribed only for health reasons. The first generation of drugs is also characterized by high hepato- and nephrotoxicity.

Aminoglycosides

Aminoglycosides have found active use in the treatment of bacterial infections caused by gram-negative flora. They have a bactericidal effect. Their high efficiency, which does not depend on the functional activity of the patient’s immune system, has made them an indispensable remedy for immune disorders and neutropenia. The following generations of aminoglycosides are distinguished:

Aminoglycosides are prescribed for infections of the respiratory system, sepsis, infective endocarditis, peritonitis, meningitis, cystitis, pyelonephritis, osteomyelitis and other pathologies. Among the side effects, toxic effects on the kidneys and hearing loss are of great importance.

Therefore, during the course of therapy, it is necessary to regularly conduct a biochemical blood test (creatinine, GCF, urea) and audiometry. For pregnant women, during lactation, patients with chronic kidney disease or on hemodialysis, aminoglycosides are prescribed only for health reasons.

Glycopeptides

Glycopeptide antibiotics have a broad-spectrum bactericidal effect. The best known of them are bleomycin and vancomycin. In clinical practice, glycopeptides are reserve drugs that are prescribed when other antibacterial agents are ineffective or the infectious agent is specific to them.

They are often combined with aminoglycosides, which increases the combined effect against Staphylococcus aureus, enterococcus and streptococcus. Glycopeptide antibiotics have no effect on mycobacteria and fungi.

This group of antibacterial agents is prescribed for endocarditis, sepsis, osteomyelitis, phlegmon, pneumonia (including complicated), abscess and pseudomembranous colitis. Glycopeptide antibiotics should not be used in case of renal failure, hypersensitivity to drugs, lactation, acoustic neuritis, pregnancy and lactation.

Lincosamides

Lincosamides include lincomycin and clindamycin. These drugs exhibit a bacteriostatic effect on gram-positive bacteria. I use them mainly in combination with aminoglycosides as a second-line treatment for severe patients.

Lincosamides are prescribed for aspiration pneumonia, osteomyelitis, diabetic foot, necrotizing fasciitis and other pathologies.

Quite often, while taking them, candidiasis infection, headache, allergic reactions and suppression of hematopoiesis develop.

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Tetracyclines

Tetracyclines are divided into biosynthetic and semi-synthetic.

Biosynthetic tetracyclines are a waste product of radiant fungi. Their structure is based on a condensed four-cyclic tetracycline system.

Tetracyclines act bacteriostatically: they inhibit the biosynthesis of microbial cell proteins in ribosomes. Most active against reproducing bacteria. They have a wide spectrum of action, which extends to gram-positive and gram-negative cocci and rods. Tetracyclines are effective against staphylococci, streptococci, pneumococci and actinomycetes, as well as against spirochetes, rickettsia, chlamydia and protozoa. They have no effect on Proteus, Pseudomonas aeruginosa, mycobacteria, viruses and fungi.

Tetracyclines are the drugs of choice for severe infections: brucellosis, cholera, plague, typhus and typhoid fever. Effective for pneumonia caused by mycoplasmas, chlamydial infections, gonorrhea, syphilis, leptospirosis, amoebic dysentery, rickettsiosis, etc.

Tetracyclines penetrate well through many tissue barriers, including the placental barrier. Certain amounts pass through the blood-brain barrier. Tetracyclines are excreted in urine and bile, some of them are reabsorbed from the intestine.

Tetracyclines form poorly soluble, non-absorbable complexes with metal ions, which reduces their antimicrobial activity. Therefore, tetracyclines should not be taken orally at the same time with dairy products, antacids, iron supplements, or other metals.

Tetracyclines often cause unwanted side effects and complications:

The irritant effect when taking drugs orally is one of the main causes of dyspeptic symptoms (nausea, vomiting, diarrhea), glossitis, stomatitis and other disorders in the mucous membrane of the digestive canal;

Have a toxic effect on the liver, kidneys, blood system;

Can cause photosensitivity and associated dermatitis;

They are deposited in tissues rich in calcium (bone, tooth enamel, bind with calcium ions, and the structure of the skeleton is disrupted, staining (yellow) and damage to the teeth occurs;

They inhibit intestinal microflora and contribute to the development of candidomycosis and superinfection (staphylococcal enteritis). To prevent and treat candidomycosis, tetracyclines are combined with an antifungal antibiotic nystatin.

The use of tetracyclines is contraindicated for pregnant and lactating women and children under 12 years of age. Prescribed with caution for liver and kidney dysfunction, leukopenia, and gastrointestinal diseases.

Biosynthetic tetracyclines.Tetracycline hydrochloride is a short-acting antibiotic – 6-8 hours. It is prescribed orally in film-coated tablets. Tetracycline ophthalmic ointment is used to treat local processes - trachoma, blepharitis, bacterial conjunctivitis.

Semi-synthetic tetracyclines. Doxycycline hydrochloride (medomycin, tardox) It is well absorbed from the gastrointestinal tract and is slowly eliminated from the body, so it is prescribed in a smaller daily dose, 1-2 times a day.

Drugs are produced Unidox Solutab in the form of instant tablets. The drug contains doxycycline in the form of monohydrate, so it is less likely to cause unwanted effects, especially from the gastrointestinal tract, and can be used from 8 years of age.

Chloramphenicols

There are four stereoisomers of natural chloramphenicol, of which only levorotatory, called chloramphenicol, is active against microorganisms.

The mechanism of antimicrobial action of chloramphenicol is associated with disruption of protein synthesis of microorganisms (bacteriostatic effect).

Chloramphenicol (chloramphenicol) has a wide spectrum of action. It covers gram-positive and gram-negative bacteria and cocci, rickettsia, spirochetes, chlamydia. Not active against anaerobes, Pseudomonas aeruginosa, protozoa, mycobacteria, fungi and viruses. Resistance of microorganisms to it develops relatively slowly. Levomycetin is well absorbed from the gastrointestinal tract. Penetrates into all tissues, including passing through the blood-brain barrier and placenta. It undergoes chemical transformations in the liver and is excreted by the kidneys in the form of metabolites.

The main indications for its use are typhoid fever, paratyphoid fever, intestinal infections, rickettsiosis, brucellosis and other infections.

The following are known undesirable side effects:

Severe inhibition of hematopoiesis up to aplastic anemia with a fatal outcome; therefore, the use of chloramphenicol requires regular monitoring of the blood picture;

Irritation of the mucous membranes of the digestive tract (nausea, vomiting);

Inhibition of normal intestinal flora, dysbacteriosis, candidomycosis;

Allergic reactions in the form of skin rashes, dermatitis, fever, etc.

Contraindications: inhibition of hematopoiesis, liver disease, pregnancy, childhood.

Chloramphenicol should not be prescribed for more than 2 weeks, simultaneously with drugs that inhibit hematopoiesis (sulfonamides, pyrozolones, etc.)

Levomycetin (chloramphenicol) is obtained from culture liquid and synthetically. It has a very bitter taste, which makes it difficult to take internally in tablets.

Topically used Sintomycin– synthetic racemate of chloramphenicol in the form of liniments and suppositories. Levomycetin is produced in eye drops and is part of combined ointments " Iruksol", "Levomekol", "Mekol borimed" for the treatment of wounds, burns, vaginal suppositories " Levometrin", ear drops " Otidep."

Aminoglycosides

Aminoglycosides in their structure they contain amino sugars associated with an aglycone, i.e. have a glycosidic structure. They have a bacteriostatic and bactericidal type of action depending on the dose; their mechanism of antimicrobial action is to disrupt the synthesis of proteins in the ribosomes of the microbial cell.

They are broad-spectrum antibiotics: effective against a number of gram-positive (staphylococci, pneumococci, etc.) and gram-negative (Escherichia coli, Proteus, salmonella, etc.) microorganisms. Highly active against acid-fast bacteria, incl. Mycobacterium tuberculosis, Pseudomonas aeruginosa, protozoa. Does not affect fungi, viruses, rickettsia, anaerobes. Resistance of pathogens develops slowly, but cross-resistance to all drugs in this group is possible.

Aminoglycosides are not absorbed from the intestine when administered orally, so they are administered by injection. Can be prescribed topically for diseases of the skin and eyes. They penetrate cells poorly and are effective only when the pathogens are extracellular. They are excreted by the kidneys, creating high concentrations in the urine.

Aminoglycosides are toxic antibiotics. The main specific undesirable effects are damage to the auditory nerves (ototoxic effect up to deafness) and kidney damage (nephrotoxic effect). The severity of these undesirable effects depends on the dose. Aminoglycosides may interfere with neuromuscular conduction, which may cause respiratory depression. When treating with aminoglycosides, it is necessary to conduct urine testing and audiometry at least once a week. Allergic reactions are also observed.

Aminoglycosides are contraindicated for kidney disease, liver and auditory nerve dysfunction. They should not be prescribed together with diuretics.

Depending on the time of discovery, spectrum of action and other characteristics, three generations of aminoglycosides are distinguished.

1st generation aminoglycosides are more effective against mycobacterium tuberculosis, causative agents of intestinal infections.

Streptomycin sulfate- a product of the vital activity of radiant fungi. Has a wide spectrum of antimicrobial action. They are used mainly in the treatment of tuberculosis, rarely - plague, tularemia, urinary tract infections, and respiratory infections. The drug is most often administered into the muscle 1-2 times a day, as well as into the body cavity.

Kanamycin sulfate Its properties are similar to streptomycin, but it is more toxic. Prescribed 2 times a day into the muscle.

Neomycin sulfate unlike streptomycin and kanamycin, it is inactive against mycobacterium tuberculosis. More toxic. Not used parenterally. It is used topically as an ointment to treat infected wounds and burns. Included in the combination ointment "Neodex", "Baneotsin", "Neoderm" vaginal tablets " Terzhinan", "Sikozhinaks" and etc.

Aminoglycosides of the 2nd generation have the greatest activity against Pseudomonas aeruginosa, Proteus, Escherichia coli and some staphylococci.

Gentamicin sulfate has a bactericidal effect on gram-negative microorganisms. It is used for urinary tract infections, sepsis, wound infections, burns, etc. It is prescribed 2 times a day. Used in injections, eye drops, hydrogel plates. Included in combination eye drops " Gentadex».

Tobramycin sulfate highly active against Pseudomonas aeruginosa. Indications for use are similar to gentamicin. Eye drops available Tobrex, Tobrom, included in combination eye drops " Tobradex", "Dexatobrom"with glucocorticoids.

3rd generation aminoglycosides have a wider spectrum of antimicrobial action, including aerobic gram-negative bacteria (Pseudomonas aeruginosa, Proteus, Escherichia coli, etc.), and Mycobacterium tuberculosis. Most gram-positive anaerobic bacteria are not affected.

Amikacin sulfate is a semi-synthetic derivative of kanamycin. It is a highly active drug. Prescribed for severe bacterial infections: peritonitis, sepsis, meningitis, osteomyelitis, pneumonia, lung abscess, tuberculosis, purulent infections of the skin and soft tissues, etc. The frequency of injections is 2 times a day.

Framycetin (framinazine, isofra) has a bactericidal effect. Active against gram-positive and gram-negative bacteria that cause upper respiratory tract infections. Available in the form of a nasal spray.

Macrolides and azalides

This group includes antibiotics whose structure includes a macrocyclic lactone ring. Biosynthetic macrolides are a product of the vital activity of radiant fungi; recently, semi-synthetic drugs have also been obtained. The mechanism of the antimicrobial action of macrolides is associated with inhibition of the synthesis of microbial cell proteins.

In terms of their spectrum of antimicrobial action, macrolides resemble benzylpenicillins: they are active mainly against gram-positive microorganisms. Unlike penicillins, macrolides are active against rickettsia, chlamydia, anaerobes, etc. Those microorganisms that have developed resistance to penicillins, cephalosporins, and tetracyclines are sensitive to macrolides. They are used as reserve antibiotics for penicillin intolerance, especially for infections caused by streptococci, pneumococci and clostridia.

Sufficiently absorbed when administered orally, it penetrates well into all tissues. They do not pass through the blood-brain barrier and the placenta. Excreted in bile, partly in urine.

Used to treat pneumonia, tonsillitis, tonsillitis, scarlet fever, diphtheria, whooping cough, erysipelas, trophic ulcers, urinary and biliary tract infections, etc. Children's dosage forms are available.

Macrolides are fairly safe antimicrobial agents. Undesirable side effects are observed relatively rarely: diarrhea, allergic reactions, liver damage with long-term use. Contraindicated in case of increased individual sensitivity, liver diseases.

Biosynthetic macrolides. Erythromycin is an active antibiotic. It is prescribed orally and topically for the treatment of burns, bedsores in ointments and solutions. In the acidic environment of the stomach, erythromycin is partially destroyed, so it should be used in capsules or tablets coated to ensure drug release only in the small intestine. The reception interval is 6 hours. Included in the suspension for the treatment of acne " Zenerite».

Midecamycin (macropen, pharmacopen) is a second generation natural macrolide. Has a wide spectrum of action. Prescribed 3 times a day.

Spiramycin (doramycin, rovamycin) used for infectious and inflammatory diseases of the ENT organs, respiratory tract, gynecological diseases 2-3 times a day.

Josamycin (vilprafen) used for pneumonia, tonsillitis, skin and soft tissue infections 2 times a day.

Semi-synthetic macrolides. They have a wider spectrum of action. Effective in the treatment of sexually transmitted infections, staphylococcal infections of the skin and soft tissues, infectious diseases of the gastrointestinal tract caused by atypical bacteria - chlamydia, legionella, mycoplasma. They exhibit an anti-inflammatory effect.

Roxithromycin (Rulid, Rulox, Rulicin), are effective semi-synthetic macrolides. They are quickly absorbed when taken orally and accumulate in the tissues of the respiratory tract, kidneys, and liver. Prescribed for infections of the respiratory tract, skin, soft tissues, infections of the genitourinary system 2 times a day.

Clarithromycin (clacid, clarbact, fromilid, clarilid) 2-4 times more active than erythromycin against staphylococci and streptococci. Effective against Helicobacter pylori. Well absorbed from the gastrointestinal tract, excreted by the kidneys. Prescribed 2 times a day for infections of the respiratory tract, skin, soft tissues, gastric ulcers, etc.

Azithromycin (sumamed, sumalek, azicar, azilide, ziromin, sumamox)– broad-spectrum antibiotic. It is the first representative of a new group of macrolide antibiotics – azalides. In high concentrations at the site of inflammation it has a bactericidal effect. Used for infections of the respiratory tract, ENT organs, skin, soft tissues, gonorrhea, etc. Prescribed once a day. Undesirable effects are extremely rare.

The drug is released Zetamax in the form of a slow-release suspension, which after a single dose is effective for up to 7 days.

Lincosamides

Lincosamides are divided into biosynthetic and semi-synthetic.

Biosynthetic lincosamides.Lincomycin hydrochloride (lincocin) in therapeutic doses, it acts bacteriostatically on the microbial cell; at higher concentrations, a bactericidal effect can be observed. Suppresses protein synthesis in microbial cells.

Active against gram-positive microorganisms: aerobic cocci (staphylococci, streptococci, pneumococci), anaerobic bacteria. Resistance of microorganisms to lincomycin develops slowly. Refers to reserve antibiotics prescribed for infections caused by gram-positive microorganisms resistant to penicillin and other antibiotics.

It is well absorbed when administered orally, penetrates into all tissues, and accumulates in bone tissue. Excreted by the kidneys and bile.

Used for sepsis, osteomyelitis, pneumonia, lung abscess, purulent and wound infections, locally - for purulent-inflammatory diseases in the form of ointments, absorbable films ( Linkocel, Ferantsel).

Undesirable side effects: dyspeptic symptoms, stomatitis, pseudomembranous colitis, hematopoietic disorders; with rapid intravenous administration - decreased blood pressure, dizziness, weakness.

Contraindications: impaired renal and liver function, pregnancy.

Semi-synthetic lincosamides.Clindamycin (climycin, dalacin, vagycin)– a semi-synthetic derivative of lincomycin, similar to it in the spectrum of antimicrobial action, but more active – 2-10 times. Better absorbed from the intestines. Prescribed orally, parenterally and locally (creams, gels, vaginal suppositories).

Oxazolidinones

Linezolid (Zyvox) disrupts protein synthesis by binding to ribosomes in the microbial cell. Spectrum of action: gram-positive microorganisms (staphylococci, enterococci), gram-negative microorganisms: hemophilus influenzae, legionella, gonococcus, anaerobes. It is well absorbed from the gastrointestinal tract and creates high concentrations in many organs and tissues. Penetrates through the BBB. Excreted through the kidneys. It is used by injection for pneumonia, skin and soft tissue infections.

Undesirable effects: nausea, vomiting, diarrhea, change in taste, anemia, headache.

Rifamycins

Rifampicin– semisynthetic derivative of rifamycin. It is a broad-spectrum antibiotic. It has a bacteriostatic and, in large doses, a bactericidal effect. It is highly active against Mycobacterium tuberculosis and is a first-line anti-tuberculosis drug. Active against a large number of gram-positive and gram-negative bacteria (cocci, anthrax, clostridia, brucella, salmonella, proteus, etc.) Resistance to drugs develops quickly.

The main indications for the use of drugs are tuberculosis of the lungs and other organs. Can be used for infections of the respiratory tract, urinary and biliary tract, osteomyelitis, gonorrhea, meningitis.

Undesirable side effects: liver dysfunction, allergic reactions, dyspeptic symptoms, kidney problems, leukopenia.

Contraindications: hepatitis, renal dysfunction, pregnancy, lactation, infants.

Rifamycin (otofa) active against most microorganisms that cause inflammatory ear diseases. Used for otitis media in the form of drops.

Rifaximin (alpha normix)– an antibiotic with a broad spectrum of antimicrobial activity, including most gram-positive and gram-negative, aerobic and anaerobic bacteria that cause gastrointestinal infections. Used for gastrointestinal infections.

Antibiotics of different groups

Fusidine sodium is a derivative of fusidic acid. An antibiotic with a narrow spectrum of action, mainly affects gram-positive bacteria: staphylococci, meningococci, gonococci, less active against pneumococci and streptococci. Does not affect gram-negative bacteria, fungi and protozoa. Acts bacteriostatically. Well absorbed when taken enterally. Penetrates into all tissues, accumulates in bone tissue. Used for staphylococcal infections, especially osteomyelitis.

Undesirable side effects: dyspeptic symptoms, skin rashes, jaundice.

Fusafungin (bioparox) antibiotic for topical use. Has a wide spectrum of antibacterial action. Has an anti-inflammatory effect. Prescribed by inhalation for diseases of the upper respiratory tract (sinusitis, pharyngitis, tonsillitis, laryngitis, tracheitis).

Fosfomycin (monural)– a derivative of phosphonic acid. It has a wide spectrum of action and a bactericidal type of action (inhibits the synthesis of bacterial cell walls). Reduces the adhesion of a number of bacteria to the epithelium of the urinary tract. Used for urinary tract infections: cystitis, urethritis. Available in granules for oral administration.

The concept of infectious diseases refers to the body’s reaction to the presence of pathogenic microorganisms or their invasion of organs and tissues, manifested by an inflammatory response. For treatment, antimicrobial drugs are used that selectively act on these microbes in order to eradicate them.

Microorganisms leading to infectious and inflammatory diseases in the human body are divided into:

• bacteria (true bacteria, rickettsia and chlamydia, mycoplasma);
• mushrooms;
• viruses;
• protozoa.

Therefore, antimicrobial agents are divided into:

• antibacterial;
• antiviral;
• antifungal;
• antiprotozoal.

It is important to remember that one drug can have several types of activity.

For example, Nitroxoline ®, Rev. with a pronounced antibacterial and moderate antifungal effect - called an antibiotic. The difference between such a remedy and a “pure” antifungal agent is that Nitroxoline ® has limited activity against some species of Candida, but has a pronounced effect against bacteria on which the antifungal agent has no effect at all.

In the 50s of the twentieth century, Fleming, Chain and Florey received the Nobel Prize in Medicine and Physiology for the discovery of penicillin. This event became a real revolution in pharmacology, completely revolutionizing the basic approaches to the treatment of infections and significantly increasing the patient’s chances of a complete and rapid recovery.

With the advent of antibacterial drugs, many diseases that caused epidemics that previously devastated entire countries (plague, typhus, cholera) turned from a “death sentence” into a “disease that can be effectively treated” and are now practically non-existent.

Antibiotics are substances of biological or artificial origin that can selectively inhibit the vital activity of microorganisms.

That is, a distinctive feature of their action is that they affect only the prokaryotic cell, without damaging the cells of the body. This is due to the fact that there is no target receptor for their action in human tissues.

Antibacterial agents are prescribed for infectious and inflammatory diseases caused by the bacterial etiology of the pathogen or for severe viral infections, in order to suppress the secondary flora.

When choosing adequate antimicrobial therapy, it is necessary to take into account not only the underlying disease and the sensitivity of pathogenic microorganisms, but also the patient’s age, pregnancy, individual intolerance to the components of the drug, concomitant pathologies and taking medications that are not combined with the recommended medication.

Also, it is important to remember that if there is no clinical effect from therapy within 72 hours, the drug is changed, taking into account possible cross-resistance.

For severe infections or for the purpose of empirical therapy with an unspecified pathogen, a combination of different types of antibiotics is recommended, taking into account their compatibility.

Based on their effect on pathogenic microorganisms, they are divided into:

• bacteriostatic - inhibiting the vital activity, growth and reproduction of bacteria;
• Bactericidal antibiotics are substances that completely destroy the pathogen due to irreversible binding to the cellular target.

However, such a division is quite arbitrary, since many antib. may exhibit different activity, depending on the prescribed dosage and duration of use.

If the patient has recently used an antimicrobial agent, re-use should be avoided for at least six months to prevent the emergence of antibiotic-resistant flora.

How does drug resistance develop?

Most often, resistance is observed due to mutation of the microorganism, accompanied by a modification of the target inside the cells, which is affected by types of antibiotics.

The active substance of the prescribed solution penetrates the bacterial cell, but cannot contact the required target, since the “key-lock” binding principle is violated. Consequently, the mechanism for suppressing the activity or destroying the pathological agent is not activated.

Another effective method of protection against drugs is the synthesis by bacteria of enzymes that destroy the main structures of the antibacterial agent. This type of resistance most often occurs to beta-lactams, due to the production of beta-lactamases by the flora.

Much less common is an increase in resistance due to a decrease in the permeability of the cell membrane, that is, the drug penetrates inside in too small doses to provide a clinically significant effect.

To prevent the development of drug-resistant flora, it is also necessary to take into account the minimum concentration of suppression, which expresses a quantitative assessment of the degree and spectrum of action, as well as the dependence on time and concentration. in blood.

For dose-dependent drugs (aminoglycosides, metronidazole), the effectiveness of action depends on the concentration. in the blood and the focus of the infectious-inflammatory process.

Time-sensitive medications require repeated administrations throughout the day to maintain an effective therapeutic concentration. in the body (all beta-lactams, macrolides).

Classification of antibiotics by mechanism of action

• drugs that inhibit the synthesis of bacterial cell walls (penicillin antibiotics, all generations of cephalosporins, Vancomycin ®);
• destroying the normal organization of the cell at the molecular level and interfering with the normal functioning of the tank membrane. cells (Polymyxin ®);
• agents that help suppress protein synthesis, inhibit the formation of nucleic acids and inhibit protein synthesis at the ribosomal level (Chloramphenicol preparations, a number of tetracyclines, macrolides, Lincomycin ®, aminoglycosides);
• inhibit. ribonucleic acids - polymerases, etc. (Rifampicin ®, quinols, nitroimidazoles);
• inhibitory processes of folate synthesis (sulfonamides, diaminopyrides).

Classification of antibiotics by chemical structure and origin

1. Natural - waste products of bacteria, fungi, actinomycetes:

• Gramicidins ® ;
• Polymyxins;
• Erythromycin ® ;
• Tetracycline ® ;
• Benzylpenicillins;
• Cephalosporins, etc.

2. Semi-synthetic - derivatives of natural antibacterials:

• Oxacillin ®;
• Ampicillin ® ;
• Gentamicin ® ;
• Rifampicin ®, etc.

3. Synthetic, that is, obtained as a result of chemical synthesis:

• Levomycetin ®;
• Amikacin ®, etc.

Classification of antibiotics by spectrum of action and purposes of use

Modern classification of antibiotics by groups: table

Having no subclasses:

• Lincosamides (lincomycin ®, clindamycin ®);
• Nitrofurans;
• Hydroxyquinolines;
• Chloramphenicol (this group of antibiotics is represented by Levomycetin ®);
• Streptogramins;
• Rifamycins (Rimactan ®);
• Spectinomycin (Trobitsin ®);
• Nitroimidazoles;
• Antifolates;
• Cyclic peptides;
• Glycopeptides (vancomycin ® and teicoplanin ®);
• Ketolides;
• Dioxidine;
• Fosfomycin (Monural ®);
• Fusidane;
• Mupirocin (Bactoban ®);
• Oxazolidinones;
• Evernomycins;
• Glycylcyclines.

Groups of antibiotics and drugs in the table

Penicillins

Like all beta-lactam drugs, penicillins have a bactericidal effect. They influence the final stage of the synthesis of biopolymers that form the cell wall. As a result of blocking the synthesis of peptidoglycans, due to their effect on penicillin-binding enzymes, they cause the death of the pathological microbial cell.

The low level of toxicity to humans is due to the absence of target cells for antibacterial agents.

The mechanisms of bacterial resistance to these drugs have been overcome by the creation of protected agents enhanced with clavulanic acid, sulbactam, etc. These substances suppress the action of the tank. enzymes and protect the drug from destruction.

Natural BenzylpenicillinBenzylpenicillin Na and K salts.

Cephalosporins

Due to low toxicity, good tolerability, the ability to be used by pregnant women, as well as a wide spectrum of action, cephalosporins are the most commonly used antibacterial agents in therapeutic practice.

The mechanism of action on the microbial cell is similar to penicillins, but is more resistant to the effects of the drug. enzymes.

Rev. cephalosporins have high bioavailability and good absorption by any route of administration (parenteral, oral). They are well distributed in internal organs (with the exception of the prostate gland), blood and tissues.

Only Ceftriaxone ® and Cefoperazone ® are capable of creating clinically effective concentrations in bile.

A high level of permeability through the blood-brain barrier and effectiveness in inflammation of the meninges is noted in the third generation.

The only cephalosporin protected by sulbactam is Cefoperazone/sulbactam ® . It has an expanded spectrum of effects on flora, due to its high resistance to the influence of beta-lactamases.

The table shows groups of antibiotics and the names of the main drugs.

* They have an oral release form.

Carbapenems

They are reserve drugs and are used to treat severe nosocomial infections.

Highly resistant to beta-lactamases, effective for the treatment of drug-resistant flora. In case of life-threatening infectious processes, they are the first-priority means for an empirical regimen.

The teachers are distinguished:

• Doripenema ® (Doriprex ®);
• Imipenema ® (Tienam ®);
• Meropenem ® (Meronem ®);
• Ertapenem ® (Invanz ®).

Monobactams

• Aztreonam ® .

Rev. has a limited range of applications and is prescribed to eliminate inflammatory and infectious processes associated with Grambacteria. Effective in treating infections. processes of the urinary tract, inflammatory diseases of the pelvic organs, skin, septic conditions.

Aminoglycosides

The bactericidal effect on microbes depends on the concentration level of the agent in biological fluids and is due to the fact that aminoglycosides disrupt the processes of protein synthesis on bacterial ribosomes. They have a fairly high level of toxicity and many side effects, however, they rarely cause allergic reactions. Practically ineffective when taken orally due to poor absorption in the gastrointestinal tract.

Compared to beta-lactams, the rate of penetration through tissue barriers is much poorer. They do not have therapeutically significant concentrations in bones, cerebrospinal fluid and bronchial secretions.

Macrolides

They provide inhibition of the process of growth and reproduction of pathogenic flora, due to the suppression of protein synthesis on cell ribosomes. bacterial walls. With increasing dosage, they can have a bactericidal effect.

Also, there are combined teachers:

1. Pilobact ® is a complex solution for the treatment of Helicobacter pylori. Contains clarithromycin ® , omeprazole ® and tinidazole ® .
2. Zinerit ® is a product for external use to treat acne. The active ingredients are erythromycin and zinc acetate.

Sulfonamides

They inhibit the growth and reproduction of pathogenic microorganisms due to their structural similarity to para-aminobenzoic acid, which is involved in the life of bacteria.

They have a high rate of resistance to their action in many representatives of Gram-, Gram+. They are used as part of complex therapy for rheumatoid arthritis, retain good antimalarial activity, and are effective against toxoplasma.

Classification:

For topical use, silver sulfathiazole (Dermazin ®) is used.

Quinolones

Due to the inhibition of DNA hydrases they have a bactericidal effect and are concentration-dependent agents.

• The first generation includes non-fluorinated quinolones (nalidixic, oxolinic and pipemidic acids);
• Second pok. represented by Gram-drugs (Ciprofloxacin ®, Levofloxacin ®, etc.);
• The third is the so-called respiratory means. (Levo- and Sparfloxacin ®);
  Fourth - Rev. with antianaerobic activity (Moxifloxacin ®).

Tetracyclines

Tetracycline ®, whose name was assigned to a separate group of antibacterial agents, was first obtained chemically in 1952.

Active ingredients of the group: metacycline ®, minocycline ®, tetracycline ®, doxycycline ®, oxytetracycline ®.

On our website you can get acquainted with most groups of antibiotics, complete lists of drugs included in them, classifications, history and other important information. For this purpose, a section “” has been created in the top menu of the site.

Broad-spectrum antibiotics are often prescribed to patients. Their antimicrobial effect is aimed at bacteria, viruses, fungi and protozoa. Today, doctors have a huge number of antibiotics at their disposal. They have different origins, chemical composition, mechanism of antimicrobial action, antimicrobial spectrum and frequency of development of drug resistance. The classification of antibiotics has undergone many changes since their use in clinical practice.

There are various groups of antibiotics. However, they all have similar characteristics:

• They do not exhibit a noticeable toxic effect on the body.
• They have a pronounced selective effect on microorganisms.
• Forming drug resistance.

The term “antibiotic” has been introduced into the lexicon of medical practice since the receipt and introduction of penicillin into medical practice in 1942.

The first antibiotic was discovered back in 1929 by scientist Alexander Fleming. The English biochemist Ernst Chain was the first to obtain an antibiotic in its pure form. Then their production began. And since 1940, antibiotics have already been actively used for treatment.

Today, more than 30 groups of antimicrobial drugs are produced. They all have their own microbial spectrum and have varying degrees of effectiveness and safety.

Rice. 1. In 1945, Fleming, Florey and Chain were awarded the Nobel Prize in Physiology or Medicine “for the discovery of penicillin and its healing effects in various infectious diseases.”

Rice. 2. The photo shows the “Saving Mold” of penicillin.

“When I woke at dawn on September 28, 1928, I certainly did not plan to revolutionize medicine with my discovery of the world’s first antibiotic or killer bacteria,” Alexander Fleming, the man who invented penicillin, wrote in his diary.

Who makes antibiotics?

Antibiotics are capable of producing some strains of bacteria, fungi and actinomycetes.

Bacteria

• Strains Bacillus subtilis form bacitracin and subtilin.
• has the ability to form some types of pyocompounds (pyocinase, pyocyanin, etc.).
• Bacillus brevis forms gramicidin and tyrothricin.
• Bacillus subtilis forms some polypeptide antibiotics.
• Bacillus polimixa forms polymyxin (aerosporin).

Actinomycetes

Actinomycetes are fungal-like bacteria. More than 200 antimicrobial compounds with antibacterial, antiviral and antifungal properties have been obtained from actinomycetes. The most famous of them: streptomycin, tetracyclinin, erythromycin, neomycin, etc.

Streptomyces rimosus secrete oxytetracycline and rimocidin.

Streptomyces aureofaciens secrete chlortetracycline and tetracycline.

Streptomyces griseus forms streptomycin, mannosidostreptomycin, cycloheximide and streptocin.

Fungi

The most important manufacturers of antibiotics. Fungi produce cephalosporin,

griseofulvin, mycophenolic and penicillic acids, etc.

Penicillium notatum And Penicillium chrysogenum form penicillin.

Aspergillus flavus forms penicillin and aspergillic acid.

Aspergillus fumigatus forms fumigatin, spinulosin, fumigacin (gelvolic acid) and gliotoxin.

Rice. 3. The photo shows a colony of Bacillus subtilis, a soil bacterium. Bacillus subtilis produces some polypeptide antibiotics.

Rice. 4. In the photo, the strains Penicillium notatum and Penicillium chrysogenum form penicillin.

Rice. 5. The photo shows a colony of actinomycetes.

Bacterial cell wall and antibiotics

The painting of bacterial cells in different colors depending on the thickness of the cell was invented in 1884 by the Danish bacteriologist Hans Christian Joachim Gram. His staining method played a major role in developing the classification of bacteria.

Rice. 6. The photo shows the structure of the bacterial wall of gram-positive (right) and gram-negative (left) bacteria.

Gram-negative bacteria

In bacteria that acquire a red or pink color when stained by Gram (Gram-negative), thick, multilayered. The outer membrane of gram-negative bacteria serves as protection against certain antibiotics - lysozyme and penicillin. In addition, the lipid part of the outer leaf of the membrane of these bacteria acts as endotoxins, which, when they enter the bloodstream during infection, cause severe intoxication and toxic shock.

Gram-positive bacteria

Bacterial cells that appear purple on Gram staining (Gram-positive) have a thin cell wall. The outer sheet of their membrane lacks a lipid layer - protection from adverse conditions. Such bacteria are easily damaged by antibiotics with bacteriostatic action and antiseptics.

Rice. 7. The photo shows a Gram-stained smear. Blue gram-positive cocci and pink gram-negative bacilli are visible.

Groups of natural antibiotics

There are the following groups of antibiotics, differing in chemical composition:

• Beta-lactam antibiotics.
• Tetracycline and its derivatives.
• Aminoglycosides and aminoglycoside antibiotics.
• Macrolides.
• Levomycetin.
• Rifampicins.
• Polyene antibiotics.

Groups of antibiotics of synthetic origin (chemical drugs)

Substances that suppress the growth and reproduction of bacteria of synthetic origin are correctly called not antibiotics, but chemotherapy drugs. Today there are 14 groups. Antimicrobial chemical compounds have been created since the beginning of the 20th century. However, scientists have achieved great success in this field since the success of synthetic chemistry. The first chemical was synthesized by Paul Ehrlich in 1907. It was a drug to treat syphilis

Today, 90% of all medications sold in pharmacies are of synthetic origin.

Rice. 8. In the photo is Salvarsan or “Drug 606”. The drug was created by Paul Ehrlich on the 606th attempt. 605 experiments to create a chemical drug to treat syphilis were unsuccessful.

Sulfonamides

This group of chemotherapy drugs is represented by Norsulfazole, Sulfazine, Sulfadimezine, Sulfapyridazine, Sulfamono- and Sulfadimethoxins. Urosulfan widely used in urological practice. Biseptol is a combination drug that contains sulfamethoxazole and trimethoprim.

Drugs from the sulfonamide group block the formation of growth factors in the cell - special chemicals that take part in metabolic processes. The use of sulfonamides is limited due to their concurrent effects on human cells.

Analogues of isonicotinic acid and nitrogenous bases

Analogues of isonicotinic acid and nitrogenous bases are widely used in the treatment of tuberculosis. Drugs in this group: Phtivazid, Isoniazd, Metazide, Ethionamide, Prothionamide and PAS.

Nitrofuran derivatives

Nitrofuran derivatives have antimicrobial activity against gram-negative and gram-negative bacteria, chlamydia and trichomonas. Drugs in this group are presented Furacillin, Furazolidone and others, as well as nitro-imidazole derivatives - Metronidazole and Tinidazole. They block the processes of synthesis of daughter DNA molecules.

Quinolone/fluoroquinol group

Drugs in this group are active against gram-negative bacteria. They are presented nalidixic acid, derivatives quinolone tricarboxylic acid and quinoxaline derivatives. As these drugs were introduced into clinical practice, they were divided into 4 generations. The high antimicrobial activity of fluoroquinols gave rise to the development of dosage forms for topical use - ear and eye drops.

Imidazole derivatives

Hydroxyquinoline derivatives

Drugs in this group are active against gram-positive and gram-negative bacteria, including strains that are resistant to antibiotics. Some of them are active against protozoa ( Hiniofor), others - in relation to yeast-like fungi of the genus Candida ( Nitroxoline).

Rice. 9. Routes of administration of antibiotics.

Groups of antibiotics according to the mechanism of inhibitory action on different cell structures

Antibiotics have a detrimental effect on the microbial cell. Their “targets” are the cell wall, cytoplasmic membrane, ribosomes and nucleotide.

Antibiotics that affect the cell wall

This group of drugs is presented penicillins, cephalosporins and cycloserine.

Penicillins kill microbial cells by inhibiting the synthesis of peptidoglycan (murein), the main component of their cell membranes. This enzyme is produced only by growing cells.

Antibiotics that inhibit the synthesis of ribosomal proteins

The largest group of antibiotics that are produced by actinomycetes. She is presented aminoglycosides, tetracycline group, chloramphenicol, macrolides and etc.

Streptomycin(a group of aminoglycosides) has an antibacterial effect by blocking the 30S ribosomal subunit and disrupting the reading of genetic codons, resulting in the formation of polypeptides unnecessary for the microbe.

Tetracyclines disrupt the binding of aminoacyl-tRNA to the ribosome-matrix complex, as a result of which protein synthesis by ribosomes is suppressed.

The cytoplasmic membrane is located under the cell wall and is a lipoprotein (up to 30% lipids and up to 70% proteins). Antibacterial drugs that disrupt the function of the cytoplasmic membrane are represented by polyene antibiotics ( ) And Polymyxin. Polyene antibiotics are adsorbed on the cytoplasmic membrane of fungi and bind to its substance ergosterol. As a result of this process, the cell membrane loses macromolecules, which leads to cell dehydration and death.

Antibiotics that inhibit RNA polymerase

This group is represented by rifampicins, which are produced by actinomycetes. Rifampin inhibits the activity of DNA-dependent RNA polymerase, which leads to blocking protein synthesis when transferring information from DNA to RNA.

Rice. 10. Damage to the membrane of a bacterial cell by antibiotics leads to its death (computer modeling).

Rice. 11. The photo shows the moment of protein synthesis from amino acids by the ribosome (left) and a three-dimensional model of the ribosome of the bacterium Haloarcula marismortui (right). It is ribosomes that often become the “target” for many antibacterial drugs.

Rice. 12. The photo shows the moment of DNA doubling at the top and the RNA molecule at the bottom. Rifampin inhibits the activity of DNA-dependent RNA polymerase, which leads to blocking protein synthesis when transferring information from DNA to RNA.

Classification of antibiotics according to their effect on the microbial cell

Antibiotics have different effects on bacteria. Some of them stop the growth of bacteria (bacteriostatics), others kill (bacteriocidal action).

Antibiotics with bactericidal action

Drugs in this group kill bacterial cells. These include benzylpenicillin, its semisynthetic derivatives, cephalosporins, fluoroquinolones, aminoglycosides, rifampicins.

Antibiotics with a bacteriostatic effect

Drugs in this group stop the growth of microbes. Bacteria that have not reached a certain size are not capable of reproduction and die quickly, therefore the bacteriostatic effect is equal in strength to the bacteriocidal effect. Antibiotics in this group include tetracyclines, macrolides and aminoglycosides.

Rice. 13. Allergies can develop to antibiotics, as to other medications. The photo shows different manifestations of allergies (skin form).

Narrow and broad spectrum antibiotics

Based on their effect on microbes, antibiotics are divided into two groups: broad-spectrum (the bulk of antimicrobial drugs) and narrow.

Narrow-spectrum antibiotics

A) Benzylpenicillin has activity against pyogenic cocci, gram-positive bacteria and spirochetes.

b) Antifungal drugs of natural origin Nystatin, Levorin and Amphotericin B. They are active against fungi and protozoa.

Broad-spectrum antibiotics

Rice. 14. Tablet forms, suspensions and syrups are widely used for children. For teenagers - tablets and capsules.

Broad-spectrum antibiotics: brief description

Penicillins

Naturally occurring penicillins are considered narrow-spectrum antibiotics. Benzylpenicillin and phenoxypenicillin are most actively used in medical practice. The drugs are active against gram-positive bacteria and cocci.

Isoxalpenicillins

80–90% of strains of Staphylococcus aureus (Staphylococcus aureus) are resistant to penicillin, as they are capable of producing enzymes (penicillinases) that destroy one of the constituent parts of the molecule of all penicillins - the beta-lactam ring. Since 1957, the development of semi-synthetic antibacterial drugs began. Scientists have developed antibiotics that are resistant to the action of the staphylococcal enzyme (isoxalpenicillins). The main antistaphylococcal drugs among them are oxacillin and naphthicillin, which are widely used in the treatment.

Penicillins with an extended spectrum of activity

Extended-spectrum penicillins include:

• aminopenicillins (do not kill Pseudomonas aeruginosa),
• carboxypenicillins (active against Pseudomonas aeruginosa),
• ureidopenicillins (active against Pseudomonas aeruginosa).

Aminopenicillins (Ampicillin and Amoxicillin)

Drugs in this group are active against, Proteus mirabilis, Salmonella spp., Shigella spp., Haemophilus influenzae, Listeria monocytogenes and

Streptococcus pneumoniae.

The drugs are widely used in the treatment of upper respiratory tract infections, in the practice of ENT doctors, diseases of the urinary system and kidneys, gastrointestinal tract, including in the treatment of gastric ulcers caused by Helicobacter pylori and meningitis.

Carboxypenicillins (Carbenicillin, Ticarcillin, Carfecillin)

Like aminopenicillins, drugs in this group are effective against a number of infections, including Pseudomonas aeruginosa.

Ureidopenicillins (Piperacillin, Azlocillin, Mezlocillin)

Like aminopenicillins, drugs in this group are effective against a number of infections, including Pseudomonas aeruginosa and Klebsiella spp.

In medical practice today it is used only Azlocillin.

Carboxypenicillins and ureidopenicillins are destroyed by staphylococcal beta-lactamase enzymes.

Compounds that are beta-lactamase inhibitors (clavulanic acid, sulbactam and tazobactam) can overcome staphylococcal enzymes. Penicillins protected from the destructive action of the staphylococcal enzyme are called inhibitor-protected. They are represented by Amoxicillin/Clavulanate, Ampicillin/Sulbactam, Amoxicillin/Sulbactam, Piperacillin/Tazobactam, Ticarcillin/Clavulanate. Inhibitor-protected penicillins are widely used to treat infections of various localizations and are used for preoperative prophylaxis in abdominal surgery.

Cephalosporins

The largest group of antibiotics are cephalosporins. They cover a wide antimicrobial spectrum, have high bactericidal activity and are highly resistant to staphylococcal beta-lactamases. Cephalosporins are divided into 4 generations. 3rd and 4th generation cephalosporins have a wide spectrum of antimicrobial action. This division is based on the spectrum of antimicrobial activity and resistance to beta-lactamases. Cephalosporins kill microbial cells by inhibiting the synthesis of peptidoglycan (murein), the main component of their cell membranes.

3rd generation cephalosporins are presented Cefixime, Cefotaxime, Ceftriaxone, Ceftazidime, Cefoperazone, Ceftibuten, etc. 4th generation cephalosporins — Cefepime and Cefpirome.

The high effectiveness of cephalosporins and low toxic effect have made these antibiotics one of the most popular among all antimicrobial drugs in clinical use.

Tetracyclines

The use of tetracycline group drugs is limited today. The reason for this is the side effects of these antibiotics and the emergence of a large number of cases of tetracycline-resistant microorganisms. Natural antibiotic Tetracycline and semisynthetic antibiotic Doxycycline Today they are used for chlamydia, rickettsiosis, some diseases transmitted from animals to humans (zoonoses) and severe acne.

Aminoglycosides

Aminoglycosides lead to microbial cell death by blocking the 30S ribosomal subunit and disrupting the reading of genetic codons, resulting in the formation of polypeptides unnecessary for the microbe. As aminoglycosides are introduced into medical practice, 4 generations of antibiotics of this group are distinguished.

• The first generation is represented by Streptomycin, Neomycin, Kanamycin, Monomycin.
• II generation - Gentamicin.
• III generation - Tobramycin, Amikacin, Netilmicin, Sizomycin.
• IV generation - Isepamycin.

Aminodicosides are used to treat serious diseases such as plague, tuberculosis, tularemia, etc. They have dangerous side effects, and therefore their use in medical practice is limited (damage to the kidneys, auditory and phrenic nerves).

Macrolides

Macrolides are the most non-toxic antibiotics. They have a high degree of safety and are well tolerated by patients. Drugs in this group are presented Erythromycin, Spiramycin, Josamycin and Midecamycin- natural antibiotics and Clarithromycin, Azithromycin, Midecamycin acetate and Roxithromycin- semi-synthetic origin.

Rifampicins are semi-synthetic derivatives of a natural antibiotic Rifamycin, which is produced by actinomycetes. Antibiotics are widely used to treat tuberculosis and leprosy. Rifampicins inhibit the activity of DNA-dependent RNA polymerase, which leads to blocking protein synthesis during the transfer of information from DNA to RNA.

Rice. 17. In the photo on the left, bacterial colonies are showing resistance to antibiotic tablets. On the right there is no growth around the tablets, which means the bacteria are sensitive to antibiotics.

Rice. 18. Over the past five years, the antibiotic market in the Russian Federation has more than doubled. As they say, there is demand - there is supply. Russians' home medicine cabinets are overflowing with antimicrobial drugs. Microorganisms are becoming more and more resistant every year, which requires longer courses of treatment and new antibiotics to overcome.

Broad-spectrum antibiotics are universal soldiers in the fight against numerous pathogens. The classification of antibiotics has undergone many changes since their use in clinical practice. There are many groups of antibiotics. However, they are all united by a pronounced selective effect on microorganisms and a slight toxic effect on the macroorganism.

Content

The human body is attacked every day by many microbes that try to settle and develop at the expense of the internal resources of the body. The immune system usually copes with them, but sometimes the resistance of microorganisms is high and you have to take medications to fight them. There are different groups of antibiotics that have a certain spectrum of action and belong to different generations, but all types of this drug effectively kill pathological microorganisms. Like all powerful medications, this drug has its side effects.

What is an antibiotic

This is a group of drugs that have the ability to block protein synthesis and thereby inhibit the reproduction and growth of living cells. All types of antibiotics are used to treat infectious processes that are caused by different strains of bacteria: staphylococcus, streptococcus, meningococcus. The drug was first developed in 1928 by Alexander Fleming. Antibiotics of certain groups are prescribed for the treatment of oncological pathologies as part of combination chemotherapy. In modern terminology, this type of medication is often called antibacterial drugs.

Classification of antibiotics by mechanism of action

The first drugs of this type were medications based on penicillin. There is a classification of antibiotics according to groups and mechanism of action. Some of the drugs have a narrow focus, others have a broad spectrum of action. This parameter determines how much the medicine will affect a person’s health (both positively and negatively). Medicines help cope with or reduce the mortality rate of such serious diseases:

• sepsis;
• gangrene;
• meningitis;
• pneumonia;
• syphilis.

Bactericidal

This is one of the types from the classification of antimicrobial agents according to pharmacological action. Bactericidal antibiotics are drugs that cause lysis, the death of microorganisms. The medication inhibits membrane synthesis and suppresses the production of DNA components. The following groups of antibiotics have these properties:

• carbapenems;
• penicillins;
• fluoroquinolones;
• glycopeptides;
• monobactams;
• fosfomycin.

Bacteriostatic

The action of this group of medications is aimed at inhibiting the synthesis of proteins by microbial cells, which prevents them from further multiplying and developing. The result of the action of the drug is to limit the further development of the pathological process. This effect is typical for the following groups of antibiotics:

• lincosamines;
• macrolides;
• aminoglycosides.

Classification of antibiotics by chemical composition

The main division of drugs is based on their chemical structure. Each of them is based on a different active substance. This division helps to fight specifically against a specific type of microbe or to have a broad spectrum of action on a large number of varieties. This prevents bacteria from developing resistance (resistance, immunity) to a specific type of medication. The main types of antibiotics are described below.

Penicillins

This is the very first group that was created by man. Antibiotics of the penicillin group (penicillium) have a wide range of effects on microorganisms. Within the group there is an additional division into:

• natural penicillins - produced by fungi under normal conditions (phenoxymethylpenicillin, benzylpenicillin);
• semisynthetic penicillins are more resistant to penicillinases, which significantly expands the spectrum of action of the antibiotic (methicillin, oxacillin medications);
• extended action – preparations of ampicillin, amoxicillin;
• medicines with a wide spectrum of action - azlocillin, mezlocillin.

In order to reduce bacterial resistance to this type of antibiotics, penicillinase inhibitors are added: sulbactam, tazobactam, clavulanic acid. Vivid examples of such medications are: Tazocin, Augmentin, Tazrobida. Medicines are prescribed for the following pathologies:

• respiratory system infections: pneumonia, sinusitis, bronchitis, laryngitis, pharyngitis;
• genitourinary: urethritis, cystitis, gonorrhea, prostatitis;
• digestive: dysentery, cholecystitis;
• syphilis.

Cephalosporins

The bactericidal property of this group has a wide spectrum of action. The following generations of cephalosporins are distinguished:

• I-e, drugs cefradine, cephalexin, cefazolin;
• II, products with cefaclor, cefuroxime, cefoxitin, cefotiam;
• III, medications ceftazidime, cefotaxime, cefoperazone, ceftriaxone, cefodizime;
• IV, products with cefpirome, cefepime;
• V-e, medications fetobiprole, ceftaroline, fetolosan.

Most of the antibacterial medications in this group are available only in the form of injections, so they are used more often in clinics. Cephalosporins are the most popular type of antibiotics for inpatient treatment. This class of antibacterial agents is prescribed for:

• pyelonephritis;
• generalization of infection;
• inflammation of soft tissues, bones;
• meningitis;
• pneumonia;
• lymphangitis.

Macrolides

1. Natural. They were synthesized for the first time in the 60s of the 20th century, these include spiramycin, erythromycin, midecamycin, and josamycin.
2. Prodrugs, the active form is taken after metabolism, for example, troleandomycin.
3. Semi-synthetic. These are clarithromycin, telithromycin, azithromycin, dirithromycin.

Tetracyclines

This species was created in the second half of the 20th century. Antibiotics of the tetracycline group have an antimicrobial effect against a large number of strains of microbial flora. At high concentrations, a bactericidal effect is manifested. A feature of tetracyclines is their ability to accumulate in tooth enamel and bone tissue. This helps in the treatment of chronic osteomyelitis, but also disrupts skeletal development in young children. This group is prohibited for pregnant girls and children under 12 years of age. These antibacterial medications are represented by the following drugs:

• Oxytetracycline;
• Tigecycline;
• Doxycycline;
• Minocycline.

Contraindications include hypersensitivity to components, chronic liver pathologies, porphyria. Indications for use are the following pathologies:

• Lyme disease;
• intestinal pathologies;
• leptospirosis;
• brucellosis;
• gonococcal infections;
• rickettsiosis;
• trachoma;
• actinomycosis;
• tularemia.

Aminoglycosides

The active use of this series of medications is carried out in the treatment of infections caused by gram-negative flora. Antibiotics have a bactericidal effect. The drugs show high efficiency, which is not related to the indicator of the patient’s immune activity, making these medications indispensable for weakening of the immune system and neutropenia. The following generations of these antibacterial agents exist:

1. The drugs kanamycin, neomycin, chloramphenicol, streptomycin belong to the first generation.
2. The second includes products with gentamicin and tobramycin.
3. The third includes amikacin drugs.
4. The fourth generation is represented by isepamycin.

Indications for the use of this group of medications are the following pathologies:

• sepsis;
• respiratory tract infections;
• cystitis;
• peritonitis;
• endocarditis;
• meningitis;
• osteomyelitis.

Fluoroquinolones

One of the largest groups of antibacterial agents has a broad bactericidal effect on pathogenic microorganisms. All medications are similar to nalidixic acid. They began actively using fluoroquinolones in the 7th year; there is a classification by generation:

• medicines oxolinic, nalidixic acid;
• products containing ciprofloxacin, ofloxacin, pefloxacin, norfloxacin;
The information presented in the article is for informational purposes only. The materials in the article do not encourage self-treatment. Only a qualified doctor can make a diagnosis and give treatment recommendations based on the individual characteristics of a particular patient. Found an error in the text? Select it, press Ctrl + Enter and we will fix everything!