[Macrolides, a group of antibiotics with a broad spectrum of activity]

The new macrolide derivatives, such as roxithromycin, clarithromycin or azithromycin, respectively, extend the spectrum of activity in antimicrobial chemotherapy. Their direct antibacterial activities are more or less similar to that of erythromycin, i.e., besides gram-positive cocci and rods the gram-negative cocci are likewise susceptible to these drugs. This holds true for aerobes as well as anaerobes. Especially the cell wall deficient bacteria, such as chlamydias, rickettsias, mycoplasmas, are generally rather susceptible. Among the gram-negative aerobic rods some genera are susceptible, for example Bordetella, Haemophilus or Legionella, whereas the Enterobacteriaceae are practically resistant, because their cell wall is rather impermeable. In a few examples, i.e. mycobacteria other than tuberculosis and certain protozoa, such as Toxoplasma, the new macrolides exert a definite greater activity than erythromycin. In particular, the property of the new derivatives to be highly accumulated within host cells, especially within phagocytes, renders these drugs extremely effective against intracellular pathogens, such as Mycobacteria, Legionella, Chlamydia, Listeria, Toxoplasma. Consequently, these new derivatives definitely improve and extend the indications for macrolide antibiotics.