What are the antibiotics. Ways to use antibiotics. How drug resistance develops

Antibiotics are a huge group of bactericidal drugs, each of which is characterized by its 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 definition of GOST, antibiotics include substances of plant, animal or microbial origin. At present, this definition is somewhat outdated, since a huge number of synthetic drugs have been created, but it was precisely natural antibiotics.

Story antimicrobials begins in 1928, when A. Fleming was first discovered penicillin. This substance was just discovered, and not created, since it has always existed in nature. In wildlife, it is produced by microscopic fungi of the genus Penicillium, protecting themselves from other microorganisms.

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 Some of them are already outdated and are not used in treatment, and some are only being introduced into clinical practice.

How antibiotics work

All antibacterial drugs according to the effect of exposure to microorganisms can be divided into two large groups:

• bactericidal- directly cause the death of microbes;
• bacteriostatic- prevent the growth of microorganisms. Unable to grow and multiply, the bacteria are destroyed by the sick person's immune system.

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

Groups of antibiotics

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

The classification of antibiotics implies the presence of groups:

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

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

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

• I generation: cefazolin, cephalexin, cefradin, etc.
• II generation: cefsulodin, cefamandol, cefuroxime.
• III generation: cefotaxime, ceftazidime, cefodizime.
• IV generation: cefpir.
• V generation: ceftolosan, ceftopibrol.

The differences between different groups are mainly in their effectiveness - later generations have greater spectrum actions are more efficient. 1st and 2nd generation cephalosporins clinical practice now used extremely rarely, 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, leukomycin and a number of others. Macrolides are considered one of the safest antibacterial drugs - they can be used even by pregnant women. Azalides and ketolides are varieties of macrolides that differ in the structure of active molecules.

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

1. Aminoglycosides. Representatives: gentamicin, amikacin, kanamycin. Effective against a large number aerobic Gram-negative microorganisms. These drugs are considered the most toxic, can lead to enough serious complications. Used to treat infections urinary tract, .
2. Tetracyclines. Basically, this semi-synthetic and synthetic drugs, which include: tetracycline, doxycycline, minocycline. Effective against many bacteria. The disadvantage of these medicines 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 the first generation (pefloxacin, ciprofloxacin, norfloxacin) and the second (levofloxacin, moxifloxacin). They are most often used to treat infections of the upper respiratory tract (,) and respiratory tract (,).
4. Lincosamides. This group includes the natural antibiotic lincomycin and its derivative clindamycin. They have both bacteriostatic and bactericidal effects, the effect depends on the concentration.
5. Carbapenems. This is one of the most modern antibiotics acting on a large number of microorganisms. The drugs of this group belong to the reserve antibiotics, that is, they are used in the most difficult cases when other drugs 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 toxic effects on the nervous system and kidneys.
7. Anti-tuberculosis drugs. This is a separate group of drugs that have pronounced action on the . These include rifampicin, isoniazid, and PAS. Other antibiotics are also used to treat tuberculosis, but only if resistance has developed to the mentioned drugs.
8. Antifungals. This group includes drugs used to treat mycoses - fungal infections: amphotyrecin B, nystatin, fluconazole.

Ways to use antibiotics

Antibacterial drugs are available in different forms: tablets, powder, from which a solution for injection is prepared, ointments, drops, spray, syrup, suppositories. The main ways to use antibiotics:

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

Important:injections should be done exclusively nurse in a clinic or hospital! Doing antibiotics at home is strongly discouraged.

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 eye damage, for example, tetracycline ointment for conjunctivitis.

The route of administration is determined only by the doctor. This takes into account many factors: 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 you can dissolve the powder. For example, Abaktal can only be diluted with glucose, since when sodium chloride is used, it is destroyed, which means that the treatment will be ineffective.

Sensitivity to antibiotics

Any organism sooner or later gets used to the most severe conditions. This statement is also true in relation to microorganisms - in response to prolonged exposure microbes develop resistance to antibiotics. The concept of sensitivity to antibiotics was introduced into medical practice - with what efficiency this or that drug affects the pathogen.

Any prescription of antibiotics should be based on knowledge of the susceptibility of the pathogen. Ideally, before prescribing the drug, the doctor should conduct a sensitivity test, and prescribe the most effective drug. But the timing of such an analysis is best case- a few days, and during this time the infection can lead to the saddest result.

Therefore, in case of an 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. Antibiotics are used for this. a wide range actions.

After performing a sensitivity test, the doctor has the opportunity to change the drug to a more effective one. Replacement of the drug can be made in the absence of the effect of treatment for 3-5 days.

Etiotropic (targeted) prescription of antibiotics is more effective. In this case, it turns out what caused the disease - with the help of bacteriological research the type of exciter is set. Then the doctor selects a specific drug to which the microbe has no resistance (resistance).

Are antibiotics always effective?

Antibiotics only work on bacteria and fungi! Bacteria are unicellular 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 become the cause of the disease only when certain conditions, for example, when they enter a habitat that is not typical for them. For example, very often prostatitis is caused by E. coli that enters ascending way in 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 of their ability. Therefore, antibiotics for colds do not have an effect, since colds in 99% of cases are caused by viruses.

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

Important:Do not prescribe antibiotics to yourself! This will only lead to the fact that some of the pathogens will develop resistance, and the next time the disease will be much more difficult to cure.

Of course, antibiotics are effective for - this disease has only bacterial nature caused by streptococci or staphylococci. For the treatment of angina use the most simple antibiotics- penicillin, erythromycin. The most important thing in the treatment of angina is compliance with the frequency of taking drugs and the duration of treatment - at least 7 days. You can not stop taking the medicine immediately after the onset of the condition, which is usually noted for 3-4 days. True tonsillitis should not be confused with tonsillitis, which may be of viral origin.

Note: untreated angina can cause acute rheumatic fever or !

Inflammation of the lungs () can have both bacterial and viral origin. Bacteria cause pneumonia in 80% of cases, therefore, even with empirical prescription, antibiotics for pneumonia have good effect. In viral pneumonia, antibiotics do not have a therapeutic effect, although they prevent the bacterial flora from joining the inflammatory process.

Antibiotics and alcohol

Simultaneous reception alcohol and antibiotics short span time does not lead to anything good. Some drugs are broken down in the liver, like alcohol. The presence of an antibiotic and alcohol in the blood puts a heavy burden on the liver - it simply does not have time to neutralize ethanol. As a result, the likelihood of developing unpleasant symptoms: nausea, vomiting, intestinal disorders.

Important: a number of drugs interact with alcohol at the chemical level, as a result of which the therapeutic effect is directly reduced. These drugs include metronidazole, chloramphenicol, cefoperazone and a number of others. The simultaneous use of alcohol and these drugs can not only reduce healing effect but also lead to shortness of breath, convulsions 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 - course antibiotic therapy rarely exceeds 1.5-2 weeks.

Antibiotics during pregnancy

pregnant women get sick infectious diseases no less than all the others. But the treatment of pregnant women with antibiotics is very difficult. In the body of a pregnant woman, a fetus grows and develops - an unborn child, very sensitive to many chemicals. The ingress of antibiotics into the developing organism can provoke the development of fetal malformations, toxic damage to the central nervous system fetus.

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

It is impossible to refuse the prescription of antibiotics to a pregnant woman with the following diseases:

• Pneumonia;
• angina;
• infected wounds;
• specific infections: brucellosis, borreliosis;
• genital infections:,.

What antibiotics can be prescribed to a pregnant woman?

Penicillin, cephalosporin preparations, erythromycin, josamycin have almost no effect on the fetus. Penicillin, although it passes through the placenta, does not adversely affect the fetus. Cephalosporin and other named drugs cross 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 a woman can simply die without antibiotics.

Which of the 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- disturbs the formation skeletal system and teeth;
• chloramphenicol- dangerous to later dates pregnancy due to inhibition of functions bone marrow The child has.

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

It should be noted that before you should also stop taking antibiotics or change plans for conception. Some drugs have a cumulative effect - they are able to accumulate in a woman's body, and for some time after the end of the course of treatment they are gradually metabolized and excreted. Pregnancy is recommended no earlier than 2-3 weeks after the end of antibiotics.

Consequences of taking antibiotics

The ingress of antibiotics into the human body leads not only to the destruction of pathogenic bacteria. Like all foreign chemicals, antibiotics have systemic action- in one way 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 is different: a rash on the body, Quincke's edema ( angioedema), anaphylactic shock. If a allergic rash practically not dangerous, then anaphylactic shock can lead to death. The risk of shock is much higher with antibiotic injections, which is why injections should only be given in medical facilities - 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 - against the background of antibiotic therapy, toxic hepatitis. Individual drugs have a selective toxic effect on other organs: aminoglycosides - on the hearing aid (cause deafness); tetracyclines inhibit growth bone tissue in children.

note: the toxicity of the drug usually depends on its dose, but with individual intolerance, sometimes smaller doses are enough to show the effect.

Impact on the gastrointestinal tract

When taking certain antibiotics, patients often complain of stomach pain, nausea, vomiting, stool disorders (diarrhea). These reactions are most often due to the local irritating effect of drugs. Specific impact antibiotics on the intestinal flora leads to functional disorders its activities, which is most often accompanied by diarrhea. This condition is called antibiotic-associated diarrhea, which is popularly known as dysbacteriosis after antibiotics.

Other side effects

To others side effects include:

• suppression of immunity;
• the emergence of antibiotic-resistant strains of microorganisms;
• superinfection is a condition in which resistant to this antibiotic microbes, leading to the emergence of a new disease;
• violation of vitamin metabolism - due to the inhibition of the natural flora of the colon, which synthesizes some B vitamins;
• Jarisch-Herxheimer bacteriolysis is a reaction that occurs when bactericidal drugs are used, when, as a result of the simultaneous death of a large number of bacteria, a large amount 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 for the slightest sign colds. Antibiotics do not have a preventive effect - they treat the cause of the disease, that is, they eliminate microorganisms, and in the absence they appear only side effects drugs.

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

• surgery- in this case, the antibiotic 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 in 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 in unprotected sexual contact with a potentially sick person, as well as among health workers who have blood infected person or another biological fluid got on the mucous membrane;
• penicillin can be given to children for the prevention of rheumatic fever, which is a complication of tonsillitis.

Antibiotics for children

The use of antibiotics in children in general does not differ from their use in other groups of people. children young age pediatricians most often prescribe antibiotics in syrup. This dosage form more convenient to take, unlike injections, it is completely painless. Older children may be prescribed antibiotics in tablets and capsules. In severe cases, infections progress to parenteral route injections - injections.

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

Antibiotics are very effective drugs while having a large number of side effects. In order to be cured with their help and not harm your body, you should take them only as directed by your doctor.

What are antibiotics? When are antibiotics needed and when are they dangerous? The main rules of antibiotic treatment are told by the pediatrician, Dr. Komarovsky:

Gudkov Roman, resuscitator

Antibiotics are a group of natural and semi-synthetic organic substances that are able to act with destructive force microbes and prevent their reproduction. There is now a wide variety of antibiotics that have various properties. Many of them are even banned for use, because they have increased toxicity. All antibiotics are chemical structure and action are divided into groups.

The main groups of antibiotics are:

• a group of penicillins;
• a group of cephalosporins;
• macrolide antibiotics;
• antibiotics of the tetracycline group;
• aminoglycoside antibiotics.

If you are prescribed for treatment potent drugs After reading this article, you will be able to determine which group of antibiotics your drug belongs to, and how correctly it is prescribed.

macrolide antibiotics

Antibiotics of the macrolide group are the least toxic to the human body. The drugs that belong to this group have antimicrobial, bacteriostatic, anti-inflammatory and immunomodulatory effects. They are used for diseases such as sinusitis, bronchitis, pneumonia, syphilis, diphtheria and periodontitis. If a person has a severe form acne, toxoplasmosis or mycobacteriosis, then you can use one of these drugs.

Antibiotics of the macrolide group are strictly prohibited for people prone to allergic reactions. You can not take them during pregnancy, breastfeeding. Elderly people, as well as those who have heart disease, should be wary of taking these drugs.

Antibiotics of the penicillin group

To antibiotics penicillin group include those drugs that have the ability to resist the emergence of bacterial cells, i.e. prevent their growth and reproduction. Penicillins are very useful properties- they fight infectious diseases, the causative agent of which is inside the cells of the body, and are harmless to the person who is taking the treatment. The most common drug from the antibiotics of the penicillin group is Amoxiclav. The disadvantages of the penicillin group include their rapid elimination from the body.

Antibiotics of the cephalosporin group

Cephalosporins are part of the group of beta-lactam antibiotics and are structurally similar to penicillin. Antibiotics of the cephalosporin group are used to treat many infectious diseases. These antibiotics have one very important advantage: they fight those microbes that are resistant to penicillin. Antibiotics of the cephalosporin group are used for diseases of the respiratory tract, urinary system, and various intestinal infections.

Antibiotics of the tetracycline group

Antibiotics of the tetracycline group include Tetracycline, Doxycycline, Oxytetracycline, Metacycline. These drugs are used to fight bacteria. At long-term use antibiotics of the tetracycline group can cause side effects such as hepatitis, dental damage, allergies.

Antibiotics of the fluoroquinolone group

Antibiotics of the fluoroquinolone group are used in infectious diseases. respiratory system, urinary organs, ENT organs and many other diseases. Antibiotics of this group include Ofloxacin, Norfloxacin, Levofloxacin.

Aminoglycoside antibiotics

Aminoglycoside antibiotics are used to treat severe infections. They rarely cause an allergic reaction, but are very toxic.

Antibiotic - a substance "against life" - a drug that is used to treat diseases caused by living agents, usually various pathogenic bacteria.

Antibiotics are divided into many types and groups for a variety of reasons. The classification of antibiotics allows you to most effectively determine the scope of each type of drug.

1. Depending on the origin.

• Natural (natural).
• Semi-synthetic - on initial stage production, the substance is obtained from natural raw materials, and then they continue to artificially synthesize the drug.
• Synthetic.

Strictly speaking, only preparations obtained from natural raw materials are actually antibiotics. All other medicines are called "antibacterial drugs." AT modern world The term "antibiotic" refers to all types of drugs that can fight live pathogens.

What are natural antibiotics made from?

• from fungi;
• from actinomycetes;
• from bacteria;
• from plants (phytoncides);
• from tissues of fish and animals.

2. Depending on the impact.

• Antibacterial.
• Antitumor.
• Antifungal.

3. According to the spectrum of influence on one or another number of different microorganisms.

• Narrow spectrum antibiotics.
  These drugs are preferred for treatment, since they act purposefully on a certain type (or group) of microorganisms and do not suppress healthy microflora the patient's body.
• Broad spectrum antibiotics.

4. By the nature of the impact on the bacterial cell.

• Bactericidal drugs - destroy pathogens.
• Bacteriostatics - stop the growth and reproduction of cells. Subsequently, the body's immune system must independently cope with the remaining bacteria inside.

5. According to the chemical structure.
For those who study antibiotics, classification by chemical structure is decisive, since the structure of the drug determines its role in the treatment of various diseases.

1. Beta lactam preparations

1. Penicillin is a substance produced by colonies of mold fungi of the Penicillinum species. Natural and artificial derivatives of penicillin have a bactericidal effect. The substance destroys the walls of bacterial cells, which leads to their death.

Pathogenic bacteria adapt to drugs and become resistant to them. The new generation of penicillins is supplemented with tazobactam, sulbactam and clavulanic acid, which protect the drug from destruction inside bacterial cells.

Unfortunately, penicillins are often perceived by the body as an allergen.

Groups of penicillin antibiotics:

• Penicillins natural origin- are not protected from penicillinase - an enzyme that produces modified bacteria and which destroys the antibiotic.
• Semi-synthetics - resistant to bacterial enzyme:
  biosynthetic penicillin G - benzylpenicillin;
  aminopenicillin (amoxicillin, ampicillin, becampicillin);
  semi-synthetic penicillin (drugs of methicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin).

2. Cephalosporin.

It is used in the treatment of diseases caused by bacteria resistant to penicillins.

Today, 4 generations of cephalosporins are known.

1. Cefalexin, cefadroxil, ceporin.
2. Cefamesin, cefuroxime (axetil), cefazolin, cefaclor.
3. Cefotaxime, ceftriaxone, ceftizadime, ceftibuten, cefoperazone.
4. Cefpir, cefepime.

Cephalosporins also cause allergic reactions in the body.

Cephalosporins are used for surgical interventions ah, to prevent complications in the treatment of ENT diseases, gonorrhea and pyelonephritis.

2. Macrolides
They have a bacteriostatic effect - they prevent the growth and division of bacteria. Macrolides act directly on the focus of inflammation.
Among modern antibiotics, macrolides are considered the least toxic and give a minimum of allergic reactions.

Macrolides accumulate in the body and are used in short courses of 1-3 days. They are used in the treatment of inflammation of the internal ENT organs, lungs and bronchi, infections of the pelvic organs.

Erythromycin, roxithromycin, clarithromycin, azithromycin, azalides and ketolides.

3. Tetracycline

A group of preparations of natural and artificial origin. They have bacteriostatic action.

Tetracyclines are used in the treatment of severe infections: brucellosis, anthrax, tularemia, respiratory and urinary tract infections. The main disadvantage of the drug is that bacteria very quickly adapt to it. Tetracycline is most effective for topical application in the form of ointments.

• Natural tetracyclines: tetracycline, oxytetracycline.
• Semi-sentitic tetracyclines: chlortethrin, doxycycline, metacycline.

4. Aminoglycosides

Aminoglycosides are highly toxic bactericidal drugs active against gram-negative aerobic bacteria.
Aminoglycosides quickly and effectively destroy pathogenic bacteria even with a weakened immune system. To start the mechanism of bacteria destruction, aerobic conditions are required, that is, antibiotics of this group do not “work” in dead tissues and organs with poor blood circulation (caverns, abscesses).

Aminoglycosides are used in the treatment next states: sepsis, peritonitis, furunculosis, endocarditis, pneumonia, bacterial damage to the kidneys, urinary tract infections, inflammation of the inner ear.

Aminoglycoside preparations: streptomycin, kanamycin, amikacin, gentamicin, neomycin.

5. Levomycetin

A drug with a bacteriostatic mechanism of action on bacterial pathogens illness. It is used to treat serious intestinal infections.

An unpleasant side effect of treatment with chloramphenicol is damage to the bone marrow, in which there is a violation of the process of producing blood cells.

6. Fluoroquinolones

Preparations with a wide range of effects and a powerful bactericidal effect. The mechanism of action on bacteria is to disrupt DNA synthesis, which leads to their death.

Fluoroquinolones are used for local treatment eyes and ears, due to a strong side effect. The drugs affect the joints and bones, are contraindicated in the treatment of children and pregnant women.

Fluoroquinolones are used against the following pathogens: gonococcus, shigella, salmonella, cholera, mycoplasma, chlamydia, Pseudomonas aeruginosa, legionella, meningococcus, mycobacterium tuberculosis.

Drugs: levofloxacin, gemifloxacin, sparfloxacin, moxifloxacin.

7. Glycopeptides

Antibiotic mixed type effects on bacteria. In relation to most species, it has a bactericidal effect, and in relation to streptococci, enterococci and staphylococci, it has a bacteriostatic effect.

Glycopeptide preparations: teicoplanin (targocid), daptomycin, vancomycin (vankacin, diatracin).

8. TB antibiotics
Drugs: ftivazid, metazid, saluzid, ethionamide, prothionamide, isoniazid.

9. Antibiotics with antifungal effect
Destroy the membrane structure of fungal cells, causing their death.

10. Anti-leprosy drugs
Used to treat leprosy: solyusulfone, diucifon, diaphenylsulfone.

11. Anticancer drugs– anthracycline
Doxorubicin, rubomycin, carminomycin, aclarubicin.

12. Lincosamides
In terms of their medicinal properties, they are very close to macrolides, although chemical composition- This is a completely different group of antibiotics.
Ingredients: Delacin C.

13. Antibiotics used in medical practice, but do not belong to any of the known classifications.
Fosfomycin, fusidine, rifampicin.

Table of drugs - antibiotics

Classification of antibiotics into groups, the table distributes some types of antibacterial drugs depending on the chemical structure.

The main classification of antibacterial drugs is carried out depending on their chemical structure.

Antibiotics are a group of medicines that harm or kill bacteria that cause infectious diseases. As antiviral agents this type of medicine is not used. Depending on the ability to destroy or inhibit certain microorganisms, there are different groups antibiotics. In addition, this type of medication can be classified by origin, the nature of the effect on bacterial cells, and some other features.

general description

Antibiotics belong to the group of antiseptic biological preparations. They are the waste products of moldy and radiant mushrooms and some types of bacteria. Currently, more than 6,000 natural antibiotics are known. In addition, there are tens of thousands of synthetic and semi-synthetic. But in practice, only about 50 such drugs are used.

Main groups

All such drugs available on this moment are divided into three large groups:

• antibacterial;
• antifungal;
• antitumor.

In addition, according to the direction of action, this type of medicine is divided into:

• active against gram-positive bacteria;
• anti-tuberculosis;
• active against both gram-positive and gram-negative bacteria;
• antifungal;
• destroying helminths;
• antitumor.

Classification according to the type of effect on microbial cells

In this regard, there are two main groups of antibiotics:

• Bacteriostatic. Medicines of this type inhibit the development and reproduction of bacteria.
• Bactericidal. When using drugs from this group, the destruction of existing microorganisms occurs.

Species by chemical composition

The classification of antibiotics into groups in this case is as follows:

• Penicillins. This is the oldest group, from which, in fact, the development of this direction of drug treatment began.
• Cephalosporins. This group is used very widely and has a high degree of resistance to the destructive action of β-lactamases. So called special enzymes secreted by pathogens.
• Macrolides. These are the safest and most effective antibiotics.
• Tetracyclines. These drugs are used mainly for the treatment of the respiratory and urinary tract.
• Aminoglycosides. They have a very wide spectrum of action.
• Fluoroquinolones. Low-toxic drugs with bactericidal action.

These antibiotics are used in modern medicine most often. In addition to them, there are some others: glycopeptides, polyenes, etc.

Antibiotics of the penicillin group

Medicines of this variety are the fundamental basis of absolutely any antimicrobial treatment. At the beginning of the last century, no one knew about antibiotics. In 1929, the Englishman A. Fleming discovered the very first such remedy - penicillin. The principle of action of drugs of this group is based on the suppression of protein synthesis of the pathogen cell walls.

On the this moment There are only three main groups of penicillin antibiotics:

• biosynthetic;
• semi-synthetic;
• semi-synthetic broad-spectrum.

The first variety is used mainly for the treatment of diseases caused by staphylococci, streptococci, meningococci, etc. Such antibiotics can be prescribed, for example, for diseases such as pneumonia, infectious lesions skin, gonorrhea, syphilis, gas gangrene, etc.

Semi-synthetic antibiotics of the penicillin group are most often used to treat severe staphylococcal infections. Such drugs are less active against certain types of bacteria (for example, gonococci and meningococci) than biosynthetic ones. Therefore, before their appointment, procedures such as isolation and accurate identification of the pathogen are usually performed.

Broad-spectrum semi-synthetic penicillins are usually used if traditional antibiotics (levomycetin, tetracycline, etc.) do not help the patient. This variety includes, for example, the rather commonly used amoxicillin group of antibiotics.

Four generations of penicillins

In honey. In practice, four types of antibiotics from the penicillin group are currently used:

• First generation - medicines natural origin. This type of drug is characterized by a very narrow spectrum of application and not very good resistance to the effects of penicillinases (β-lactamases).
• The second and third generation are antibiotics that are much less affected by the destructive enzymes of bacteria, and therefore more effective. Treatment with their use can take place in a fairly short time.
• The fourth generation includes broad-spectrum penicillin antibiotics.

The most famous penicillins are the semi-synthetic drugs "Ampicillin", "Carbenicillin", "Azocillin", as well as the biosynthetic "Benzylpenicillin" and its durant forms (bicillins).

Side effects

Although the antibiotics of this group belong to low-toxic drugs, they, along with beneficial influence can affect the human body and negatively. Side effects when using them are as follows:

• itching and skin rash;
• allergic reactions;
• dysbacteriosis;
• nausea and diarrhea;
• stomatitis.

You can not use penicillins simultaneously with antibiotics of another group - macrolides.

Amoxicillin group of antibiotics

This type of antimicrobial drugs belongs to penicillins and is used to treat diseases when infected with both gram-positive and gram-negative bacteria. Such drugs can be used to treat both children and adults. Most often, antibiotics based on amoxicillin are prescribed for respiratory tract infections and different kind diseases of the gastrointestinal tract. They are also taken for diseases of the genitourinary system.

The amoxicillin group of antibiotics is used and various infections soft tissues and skin. Side effects of these drugs can cause the same as other penicillins.

Group of cephalosporins

The action of drugs in this group is also bacteriostatic. Their advantage over penicillins is their good resistance to β-lactamases. Antibiotics of the cephalosporin group are classified into two main groups:

• taken parenterally (bypassing the gastrointestinal tract);
• taken orally.

In addition, cephalosporins are classified into:

• First generation drugs. They differ in a narrow spectrum of action and have practically no effect on gram-negative bacteria. Moreover, such drugs are successfully used in the treatment of diseases caused by streptococci.
• Second generation cephalosporins. More effective against Gram-negative bacteria. Active against staphylococci and streptococci, but have virtually no effect on enterococci.
• Third and fourth generation drugs. This group of drugs is very resistant to the action of β-lactamases.

The main disadvantage of such a drug as antibiotics of the cephalosporin group is that, when taken orally, they very strongly irritate the gastrointestinal mucosa (except for the drug "Cefalexin"). The advantage of drugs of this variety is a much smaller number of side effects caused compared to penicillins. Most often in medical practice, the drugs "Cefalotin" and "Cefazolin" are used.

Negative effects of cephalosporins on the body

Side effects sometimes manifested in the process of taking antibiotics of this series include:

• negative impact on the kidneys;
• violation of hematopoietic function;
• various kinds of allergies;
• negative impact on the gastrointestinal tract.

macrolide antibiotics

Among other things, antibiotics are classified according to the degree of selectivity of action. Some are able to negatively affect only the cells of the pathogen, without affecting human tissue in any way. Others may have on the patient's body toxic effect. Preparations of the macrolide group are considered the safest in this regard.

There are two main groups of antibiotics of this variety:

• natural;
• semi-synthetic.

The main advantages of macrolides include the highest efficiency of bacteriostatic effects. They are especially active against staphylococci and streptococci. Among other things, macrolides do not adversely affect the gastrointestinal mucosa, and therefore are often available in tablets. All antibiotics affect the immune system person. Some species are depressing, some are beneficial. Antibiotics of the macrolide group have a positive immunomodulatory effect on the patient's body.

Popular macrolides are Azithromycin, Sumamed, Erythromycin, Fuzidin, etc.

Antibiotics of the tetracycline group

Medicines of this variety were first discovered in the 40s of the last century. The very first tetracycline drug was isolated by B. Duggar in 1945. It was called "Chlortetracycline" and was less toxic than other antibiotics that existed at that time. In addition, it turned out to be very effective in terms of influencing pathogens. huge amount very dangerous diseases (for example, typhoid).

Tetracyclines are considered somewhat less toxic than penicillins, but have more negative impact on the body than macrolide antibiotics. Therefore, at the moment they are being actively replaced by the latter.

Today, the drug "Chlortetracycline", discovered in the last century, oddly enough, is very actively used not in medicine, but in agriculture. The fact is that this drug is able to accelerate the growth of animals taking it, almost twice. The substance has such an effect because, when it enters the intestines of the animal, it begins to actively interact with the microflora present in it.

In addition to, in fact, the drug "Tetracycline" in medical practice, drugs such as "Metacycline", "Vibramycin", "Doxycycline", etc. are often used.

Side effects caused by antibiotics of the tetracycline group

Rejection wide application The use of drugs of this variety in medicine is primarily due to the fact that they can have not only beneficial, but also negative effects on the human body. For example, long-term use of tetracycline antibiotics can interfere with the development of bones and teeth in children. In addition, interacting with the human intestinal microflora (with misuse), such drugs often provoke the development of fungal diseases. Some researchers even argue that tetracyclines can have a depressing effect on the male reproductive system.

Aminoglycoside antibiotics

Preparations of this variety have a bactericidal effect on the pathogen. Aminoglycosides, like penicillins and tetracyclines, are one of the oldest groups of antibiotics. They were opened in 1943. In subsequent years, preparations of this variety, in particular "Streptomycin", were widely used to cure tuberculosis. In particular, aminoglycosides are effective against gram-negative aerobic bacteria and staphylococci. Among other things, some drugs of this series are active in relation to the simplest. Since aminoglycosides are much more toxic than other antibiotics, they are prescribed only for severe diseases. They are effective, for example, in sepsis, tuberculosis, severe forms paranephritis, abscesses abdominal cavity etc.

Very often, doctors prescribe aminoglycosides such as Neomycin, Kanamycin, Gentamicin, etc.

Preparations of the fluoroquinolone group

Most drugs of this type of antibiotics have a bactericidal effect on the pathogen. Their advantages include, first of all, the highest activity against a huge number of microbes. Like aminoglycosides, fluoroquinolones can be used to treat severe illness. However, they do not have such a negative impact on the human body as the first ones. There are antibiotics of the fluoroquinolone group:

• First generation. This variety is mainly used for inpatient treatment sick. First-generation fluoroquinolones are used for infections of the liver, biliary tract, pneumonia, etc.
• Second generation. These drugs, unlike the first, are very active against gram-positive bacteria. Therefore, they are prescribed, including in the treatment without hospitalization. Second-generation fluoroquinolones are widely used in the treatment of sexually transmitted diseases.

Popular drugs in this group are Norfloxacin, Levofloxacin, Gemifloxacin, etc.

So, we have found out which group antibiotics belong to, and figured out exactly how they are classified. Because most of these drugs can cause side effects, they should only be used as directed by your doctor.

- These are substances that have a detrimental effect on bacteria. Their origin can be biological or semi-synthetic. Antibiotics have saved many lives, so their discovery is of great importance for all mankind.

History of antibiotics

Many infectious diseases, such as pneumonia, typhoid fever, dysentery were considered incurable. Also, patients often died after surgical interventions, as the wounds festered, gangrene and further blood poisoning began. Until there were antibiotics.

Antibiotics were discovered in 1929 by Professor Alexander Fleming. He noticed that green mold, or rather the substance that it produces, has a bactericidal and bacteriostatic effect. The mold produces a substance Fleming called penicillin.

Penicillin has a detrimental effect on and on some types of protozoa, but absolutely no effect on the white blood cells that fight the disease.

And only in the 40s of the twentieth century began the mass production of penicillin. Around the same time, sulfamides were discovered. Scientist Gause in 1942 received gramicidin, Selman Waxman derived streptomycin in 1945.

Later, such antibiotics as bacitracin, polymyxin, chloramphenicol, tetracycline were discovered. By the end of the 20th century, all natural antibiotics had synthetic analogues.

Classification of antibiotics

There are many antibiotics available today.

First of all, they differ in the mechanism of action:

• Bactericidal action - antibiotics of the penicillin series, streptomycin, gentamicin, cephalexin, polymyxin
• Bacteriostatic action - tetracycline series, macrolides, erythromycin, chloramphenicol, lincomycin,
• Pathogenic microorganisms either die completely (bactericidal mechanism), or their growth is suppressed (bacteriostatic mechanism), and the body itself fights the disease. Antibiotics with bactericidal action help faster.

Then, they differ in the spectrum of their action:

• Broad spectrum antibiotics
• Narrow spectrum antibiotics

Preparations with a wide spectrum of action are very effective in many infectious diseases. They are also prescribed in the case when the disease is not exactly established. Destructive for almost everyone pathogenic microorganisms. But they also have a negative impact on healthy microflora.

Narrow spectrum antibiotics affect certain types bacteria. Let's consider them in more detail:

• Antibacterial effect on gram-positive pathogens or cocci (streptococci, staphylococci, enterococci, listeria)
• Effects on gram-negative bacteria ( coli, salmonella, shigella, legionella, proteus)
• Antibiotics that affect Gram-positive bacteria include penicillin, lincomycin, vancomycin, and others. The drugs that affect gram-negative pathogens include aminoglycoside, cephalosporin, polymyxin.

In addition, there are several more narrowly targeted antibiotics:

• Anti-tuberculosis drugs
• drugs
• Drugs that affect protozoa
• Anticancer drugs

Antibacterial agents vary by generation. There are now 6th generation drugs. Antibiotics latest generation have a wide spectrum of action, safe for the body, easy to use, most effective.

For example, consider penicillin preparations by generation:

• 1st generation - natural penicillins (penicillins and bicillins) - this is the first antibiotic that has not lost its effectiveness. It's cheap, it's available. Refers to drugs with a narrow spectrum of action (acts detrimental to gram-positive microbes).
• 2nd generation - semi-synthetic penicillinase-resistant penicillins (oxacillin, cloxacillin, fluclosacillin) - are less effective, unlike natural penicillin, against all bacteria except staphylococci.
• 3rd generation - penicillins with a wide spectrum of action (ampicillin, amoxicillin). Starting from the 3rd generation, antibiotics have a negative effect on both gram-positive and gram-negative bacteria.
• 4th generation - carboxypenicillins (carbenicillin, ticarcillin) - in addition to all types of bacteria, 4th generation antibiotics are effective against Pseudomonas aeruginosa. Their spectrum of action is even wider than that of the previous generation.
• 5th generation - ureidopenicillins (azlocillin, mezlocillin) - are more effective against gra-negative pathogens and Pseudomonas aeruginosa.
• 6th generation - combined penicillins - include beta-lactamase inhibitors. These inhibitors include clavulanic acid and sulbactam. Strengthen the action, increasing its effectiveness.

Of course, the higher the generation of antibacterial drugs, the wider the spectrum of action they have, respectively, and their effectiveness is higher.

Application methods

Antibiotic treatment can be carried out in several ways:

• oral
• Parenterally
• Rectally

The first way is to take the antibiotic orally or by mouth. For this method, tablets, capsules, syrups, suspensions are suitable. This drug is the most popular, but it has some disadvantages. Some types of antibiotics may be destroyed or poorly absorbed (penicillin, aminoglycoside). They also have an irritating effect on the gastrointestinal tract.

The second way to use antibacterial drugs parenterally or intravenously, intramuscularly, in spinal cord. The effect is achieved faster oral route reception.

Some types of antibiotics can be given rectally or directly into the rectum (medicated enema).

In especially severe forms of diseases, the parenteral method is most often used.

At various groups antibiotics available different localization in certain bodies and systems of the human body. According to this principle, doctors often select one or another antibacterial drug. For example, with pneumonia, azithromycin accumulates in, and in the kidneys with pyelonephritis.

Antibiotics, depending on the type, are excreted in a modified and unchanged form from the body along with urine, sometimes with bile.

Rules for taking antibacterial drugs

When taking antibiotics, certain rules must be observed. Since drugs often cause allergic reactions, they must be taken with great care. If the patient knows in advance that he has an allergy, he should immediately inform the attending physician about this.

In addition to allergies, there may be other side effects when taking antibiotics. If they were observed in the past, this should also be reported to the doctor.

In cases where there is a need to take another drug along with an antibiotic, the doctor should know about it. Often there are cases of incompatibility of medicines with each other, or the medicine reduced the effect of the antibiotic, as a result of which the treatment was ineffective.

During pregnancy and breastfeeding many antibiotics are banned. But there are drugs that can be taken during these periods. But the doctor must be made aware of the fact and feeding the baby with breast milk.

Before taking, you must read the instructions. The dosage prescribed by the doctor should be strictly observed, otherwise poisoning may occur if the drug is taken too high, and bacterial resistance to the antibiotic may develop if the drug is too low.

You can not interrupt the course of taking the drug ahead of schedule. Symptoms of the disease may return again, but in this case, this antibiotic will no longer help. You will need to change it to something else. recovery can long time don't attack. This rule is especially true for antibiotics with a bacteriostatic effect.

It is important to observe not only the dosage, but also the time of taking the drug. If the instructions indicate that you need to drink the medicine with meals, then this is how the drug is better absorbed by the body.

Along with antibiotics, doctors often prescribe prebiotics and probiotics. This is done in order to restore normal microflora intestines, which are adversely affected by antibacterial drugs. Probiotics and prebiotics treat intestinal dysbiosis.

It is also important to remember that at the first signs allergic reaction, such as pruritus, urticaria, swelling of the larynx and face, shortness of breath, you should immediately consult a doctor.

If the antibiotic does not help within 3-4 days, this is also a reason to contact the doctors. Perhaps the drug is not suitable for the treatment of this disease.

List of new generation antibiotics

There are a lot of antibiotics on the market today. It is easy to get confused in such a variety. The new generation of drugs include the following:

• Sumamed
• Amoxiclav
• Avelox
• Cefixime
• Rulid
• Ciprofloxacin
• Lincomycin
• Fusidin
• Klacid
• Hemomycin
• Roxilor
• Cefpir
• Moxifloxacin
• Meropenem

These antibiotics belong to different families or groups of antibacterial drugs. These groups are:

• Macrolides - Sumamed, Hemomycin, Rulid
• Amoxicillin group - Amoxiclav
• Cephalosporins - Cefpirome
• Fluoroquinol group - Moxifloxacin
• Carbapenems – Meropenem

All new generation antibiotics are broad-spectrum drugs. They possess high efficiency and a minimum of side effects.

The treatment period is on average 5-10 days, but in particular severe cases may be extended up to one month.

Side effects

When taking antibacterial drugs, side effects may occur. If they are pronounced, you should immediately stop taking the drug and consult a doctor.

To the most common side effects antibiotics include:

• Nausea
• vomit
• Stomach ache
• dizziness
• Headache
• Urticaria or rash on the body
• Skin itching
• Toxic effects on the liver individual groups antibiotics
• Toxic effect on the gastrointestinal tract
• Endotoxin shock
• Intestinal dysbiosis, in which there is diarrhea or constipation
• Decreased immunity and weakening of the body (fragility of nails, hair)

Since antibiotics have a large number of possible side effects, they must be taken with great care. It is unacceptable to self-medicate, this can result in serious consequences.

Especially precautions should be taken when treating children and the elderly with antibiotics. In the presence of allergies, antihistamines should be taken along with antibacterial drugs.

Treatment with any antibiotics, even a new generation, always seriously affects health. Of course, from the main infectious disease they relieve, but overall immunity is also significantly reduced. After all, not only pathogenic microorganisms die, but also normal microflora.

Recovery defensive forces it will take some time. If side effects are pronounced, especially those associated with the gastrointestinal tract, then a sparing diet will be required.

It is obligatory to take prebiotics and probiotics (Linex, Bifidumbacterin, Acipol, Bifiform and others). The start of the reception should be simultaneous with the start of taking the antibacterial drug. But after a course of antibiotics, probiotics and prebiotics should be taken for about two more weeks to populate the intestines with beneficial bacteria.

If antibiotics have a toxic effect on the liver, hepatoprotectors may be advised. These drugs will repair damaged liver cells and protect healthy ones.

As immunity declines, the body is susceptible to colds especially strong. Therefore, it is worth taking care not to overcool. Take immunomodulators, but it is better if they are plant origin(, Echinacea purpurea).

If the disease viral etiology, then antibiotics are powerless here, even a broad spectrum of action and newest generation. They can only serve as a preventive measure in joining bacterial infection to the virus. Antiviral drugs are used to treat viruses.

While watching the video you will learn about antibiotics.

It's important to lead healthy lifestyle life to get sick less often and less likely to resort to antibiotic treatment. The main thing is not to overdo it with the use of antibacterial drugs in order to prevent the emergence of bacterial resistance to them. Otherwise, it will be impossible to cure any.