The rational choice of an antibiotic is the task of the attending doctor. Due to the increasing resistance of pathogens of various pathologies to antibacterial agents, physicians have to increasingly use reserve antibiotics in everyday practice. These are drugs to which drug-resistant strains have not developed in microorganisms. However, they are more toxic and bacteria resistance develops to them quite quickly.
general information
Antibiotics are substances obtained by natural, synthetic or semi-synthetic means, capable of destroying various microorganisms. They have been used as a medicine since the last century. The following antibiotic groups are known: beta-lactams, aminoglycosides, tetracyclines, macrolides, fluoroquinolones, lincosamides and glycopeptides. They have a bacteriostatic and bactericidal effect.
Groups of antibacterial drugs formed by WHO
All antibacterial agents are divided into three groups by the World Health Organization and recommendations are given on when to use them. This is done in order to:
- inhibit antimicrobial resistance;
- optimize the treatment of infectious pathologies;
- preserve antibiotics included in the reserve for the treatment of infections that are provoked by multiresistant pathogens.
Let's consider in more detail:
- The second group includes medications recommended as antibiotics of the reserve and the choice for the treatment of certain infections. The use of drugs in this group increases the risk of resistance. Therefore, the use of Ciprofloxacin for the treatment of uncomplicated infections, such as cystitis or bacterial bronchitis, should be limited. Otherwise, the risk of further development of antibiotic resistance increases.
- The third group includes Colistin and some medications from the cephalosporin group. These drugs are called back-up or “last row”. They are indicated for use in serious and severe infections when other treatment options have failed.
This approach to the use of antibacterial agents allows you to:
- rationally and rationally use antibiotics;
- increase the effectiveness of therapy;
- reduce the rate of development of resistance to them.
The practical importance of antibiotics included in the reserve
During the period of use of these funds there is a high probability of the development of resistance of microbes to them. Especially quickly it develops to such medicines as:
- "Rifampicin";
- "Oleandomycin";
- "Streptomycin".
Slower to "Levomycetin" and drugs of the penicillin and tetracycline group. Quite rare for polymyxins. In addition, there is cross-resistance, moreover, it applies not only to the agent used, but also to medicines similar to it in the structure of the molecule. The risk of sustainability is minimal, subject to the following rules:
- rational purpose;
- optimally selected dose;
- the duration of admission corresponds to the severity of the pathology;
- an adequate combination of antibacterial agents.
In the event of resistance to the main antibiotic, it is changed to a backup.
The drug "Colistin"
This is an antibiotic of the "last reserve", it is indicated in the case when other antibacterial agents do not have an effect. Before using Colistin, a pathogenic bacterium is detected and tested for antibiotic susceptibility. The drug belongs to the group of polymyxins, and by its chemical structure it is a cyclic polypeptide. The active substance is sodium colistimethate. Its bactericidal effect is directed to gram-negative microorganisms. It disrupts the functions of the outer and cytoplasmic membranes, and also changes its structure. When taken orally, the medicine is practically not absorbed in the digestive tract, it is excreted through the intestines. Used in the following dosage forms:
- Powder for the preparation of a solution for inhalation - indicated for the treatment of respiratory diseases of an infectious nature,
- Pills - treatment and prevention of gastrointestinal infections.
Antibiotic reserve "Colistin" works for ailments caused by microorganisms sensitive to its active substance. Its high effectiveness in cystic fibrosis has been proven. In practice, the drug is rarely used to treat infections. One of the undesirable effects is nephrotoxicity, i.e., toxic effects on the kidneys, causing their damage when prescribed to individuals with impaired renal function and damaged intestinal mucosa.
Features of the use of antibiotics included in the reserve
Antibiotics of the reserve group are inferior to the main ones in one or several properties, i.e. they have:
- the rapid development of microbial resistance to them;
- low activity;
- a large number of adverse events.
In connection with the foregoing, they are indicated for intolerance or with the resistance of microorganisms to the main group of antibiotics.
To influence resistant microorganism strains, doctors recommend the following reserve medicines:
- Macrolides - Oleandomycin, Erythromycin.
- Combined - “Adimycin”, “Sigmamycin”, “Oletetrin”, “Tetraolean”.
Antimicrobial drugs included in the reserve group used in medical practice
The following is a small list of reserve antibiotics.
- "Tetracycline" is prescribed in rare cases, since the resistance of microbes to it develops quite quickly. Therefore, it belongs to the reserve group and is indicated when other antibiotics are ineffective. The pharmaceutical industry produces both external and internal dosage forms of erythromycin. It is used for pathological conditions caused by staphylococcus.
- "Levomycetin" refers to reserve funds in connection with serious adverse reactions - granulocytopenia, reticulocytopenia, aplastic anemia, which ends in death. Thus, taking this antibiotic requires regular monitoring of the hematopoietic system. To reduce the negative impact, it is prescribed for a short course of therapy. Repeated administration of Levomycetin is not recommended. It is used to treat typhoid fever, brucellosis and only with ineffective treatment with other antibacterial drugs.
- "Gentamicin", "Monomycin", "Kanamycin", "Neomycin" - drugs of the aminoglycoside group, which have strong toxicity. Their admission is carried out under the strict supervision of a doctor and with the exception of contraindications for use in each individual individual.Most often, "Gentamicin" is prescribed to combat purulent infection. The medicine “Monomycin” is allowed only for the treatment of cutaneous leishmaniasis.
- "Vancomycin" has a strong ototoxicity.
Reserve antibiotics: list
The antibiotics included in the reserve group include the following drugs. They are used only in a hospital setting:
- Amikacin;
- Ceftazidime;
- "Ciprofloxacin";
- “Cefepime”;
- Imipenem
- Miropenem;
- Vancomycin
- "Rifampicin";
- Amphotericin B
Antibiotics used to treat cystitis
Fluoroquinolones of the following generations are the drugs of choice for the treatment of this disease:
- the third is Sparfloxacin, Levofloxacin;
- the fourth is Moxifloxacin.
These drugs have high penetrating power and create a rather high concentration in the tissues. Apply them once a day, since fluoroquinolone antibacterial agents have a long half-life. Prescribe medications in the maximum allowable daily dose. Due to the wide distribution in the outpatient practice of fluoroquinolones, an increase in the resistance of urinary tract pathogens to them is observed.
If there are contraindications for taking antibiotics of this group or obtaining data on resistance, the doctor adjusts the treatment and recommends second-line drugs from the group of macrolides or tetracyclines, i.e. reserve antibiotics. With cystitis in a hospital setting, the duration of a course of treatment is from ten to fourteen days. In some cases, Meropenem, which refers to carbapenems, is prescribed from the reserve group. The result of therapy is evaluated by the bacteriological culture of urine, as well as the normalization of the level of white blood cells in the urine.
Antibiotics for influenza and SARS
Can I take reserve antibiotics for respiratory infections? The doctor recommends antibacterial medications for influenza, acute respiratory viral infections after identifying the first symptoms of pneumonia, sinusitis, tonsillitis, etc. The group of penicillins is prescribed in the absence of an allergic reaction to them. With resistance to penicillins, fluoroquinolones are preferred, and these are reserve preparations. Their use is prohibited for children, pregnant and lactating women. Cephalosporins are recommended for various pathologies of the respiratory system. For the treatment of ARVI complications, the drugs of choice are macrolides, which are also reserve drugs. Antibiotics for ARVI should be prescribed only for:
- Deterioration of the patient.
- Joining a bacterial infection.
- The appearance of purulent discharge.
- High temperature, which lasts more than three days.
In order to optimally select the appropriate antibiotic, an antimicrobial culture is done.
Conclusion
In order to prevent the development of resistant forms of bacteria, it is necessary to replace widely used antibacterial agents with new, rarely used and recently created ones. Such medicines are called reserve antibiotics. One of the most important tasks is the creation of new drugs with a pronounced selective effect, which would have activity against stable forms of microbes and have a minimum of negative effects on the body of an individual.