[Mechanisms of action of chemoantibiotics (author's transl)].

An useful drug for infectious diseases should have a selective antimicrobial activity and no action on animal cell. The general target, besides some very restricted process like in M. tuberculosis, are: 1) purine synthesis, 2) DNA replication, 3) protein synthesis, 4) cell-wall synthesis, 5) cytoplasmic membrane. On purine synthesis are active the sulphamidic on DNA replication nalidixic acid on Gram-negative bacteria, and griseophulvin on dermatophites. Many drugs have their target in the sequential stages of protein synthesis, among these the aminoglycosides are mainly bactericidal. The antibiotics which block the building of cell-wall are the best, according the target does not exist in animal cell; among them, penicillins and cephalosporins are bactericidal. On contrary cytoplasmic membrane, which is similar to the animal cell membrane has to be evaluated as a bad target. Polimyxins on bacteria, polyene antibiotics on fungi, have this target and are bactericidal, but their use is restricted for toxicity. Antibiotics must be selected in therapy according to their mechanism of action and to the immunological state of the patient. Some bactericidal antibiotics have to be reserved for immuno suppressed people.