In this Section:
28. Antiseptics and disinfectants
29. Antibacterial chemotherapeutic drugs
30. Antiviral drugs
31. Antifungal drugs
32. Antiprotozoal drugs
33. Antihelminthic drugs
ANTIMICROBIAL DRUGS1
Drugs that have antimicrobial properties are subdivided into two groups.
The first one includes the preparations that do not possess a selective antimicrobial effect. They destroy the majority of microorganisms. Antiseptics2 and disinfecting3 substances belong to this group of drugs.
Antiseptics are usually applied to the surface of covering tissues (skin, mucous membranes). Certain antiseptics are used to affect the microorganisms localized in the gastrointestinal tract and in the excretory urinary system. Depending on the concentration, they provide bacteriostatic or bactericidal effects. Disinfectants are used for the disinfection of medical instruments, equipment, premises, dishes, patients' excrements. They provide a rapidly developing effect. As a rule, they are applied at bactericidal concentrations and aimed at the prevention of the spread of infection.
It is not always possible to distinguish between antiseptics and disinfecting substances because at certain concentrations most of them work as antiseptics and at higher concentrations they are disinfectants.
The second group of substances comprises antimicrobial preparations with a selective action which are related to so-called chemotherapeutic drugs. Influencing specific microorganisms is typical of this group of preparations. Another important characteristic feature of these drugs is wide therapeutic window. The latter may be evaluated according to the range between bacteriostatic (bactericidal) concentrations and the concentrations which are toxic for the macroorganism. Chemotherapeutic drugs are used for the treatment and prevention of infections; they are also used for the treatment of infection carriers.