The basic rules of antibacterial therapy can be formulated as follows:
- Establish the causative agent of the disease;
- Determine the drugs to which the pathogen is most sensitive;
- In case of an unknown pathogen, use either a drug with a wide spectrum of action, or a combination of two drugs, the total spectrum of which includes probable pathogens;
- Start treatment as early as possible;
- The doses of drugs should be sufficient to ensure that the cells and tissues contain concentrations that prevent reproduction (bacteriostatic) or destroy bacteria (bactericidal);
- The duration of treatment should be sufficient; a decrease in body temperature and the weakening of other symptoms are not grounds for discontinuing treatment;
- A significant role is played by the choice of rational ways of administering drugs, given that some of them are not completely absorbed from the gastrointestinal tract, they do not penetrate the blood-brain barrier well;
- The combined use of antibacterial agents should be justified, since with the wrong combination, both the total activity can be weakened and their toxic effects can be summed up.
Let’s consider the antibacterial drugs themselves from the point of view of the nature, spectrum and mechanism of their action:
Antibiotics act directly on the etiological factor, and by the nature of the action there are bacteriostatic and bactericidal:
Bacteriostatic drugs inhibit the growth and reproduction of microorganisms. They do not cause their death. At the same time, it is assumed that the immune defense mechanisms are able to independently cope with the destruction and elimination of microbes. Bacteriostatic drugs include: macrolides, clindamycin, streptogramins, chloramphenicol, tetracyclines.
Bactericidal drugs lead to the death of microorganisms, the body only needs to ensure their excretion. These include: beta-lactam antibiotics, aminoglycosides, fluoroquinolones, glycopeptides and others (trimethoprim, metronidazole, rifampicin, etc.).
There are several mechanisms of action of antibiotics:
- Violation of the synthesis of the cell wall by inhibiting the synthesis of peptidoglycan (penicillin, cephalosporins, monobactams), the formation of dimers and their transfer to the growing chains of peptidoglycan (vancomycin), the synthesis of chitin (niccomycin). Antibiotics acting by this mechanism have a bactericidal nature of action, they do not act on resting cells and L-forms (devoid of a cell wall) of bacteria.
- Disruption of the functioning of membranes due to a violation of their integrity, the formation of ion channels, the binding of ions into complexes soluble in lipids and violations of their transport (nystatin, gramicidins, polymyxins).
- Suppression of the synthesis of nucleic acids: DNA (streptomycin, griseofulvin, rifampicin, rifampicin, vancomycin) and RNA (bruneomycin, rubomycin, olivomycin).
- Violation of protein synthesis by the cell (tetracyclines, macrolides).
- Violation of the synthesis of purines and pyrimidines (azaserin, sarcomycin).
- Inhibition of the respiratory chain (antimycins, oligomycins).
Antibiotics (antibacterial therapy) are one of the few groups of medicines that are used irrationally and unreasonably in 50% of cases. This is often the fault of the patients themselves, who prescribe them to themselves, their relatives and colleagues, copying the once heard treatment tactics. They prescribe them to themselves, tear them off, from abdominal and throat pains, as antipyretics and antitussives. Often, according to the same indications, they are also prescribed by pharmacists in pharmacies.
But, since its discovery, antibiotics have remained one of the most important breakthroughs in medicine. If, of course, they are used correctly.