[Spiramycin]

Spiramycin is a 16-membered ring macrolide (antibiotic). It was discovered in 1952 as a product of Streptomyces ambofaciens. As a preparation for oral administration it has been used since 1955, in 1987 also the parenteral form was introduced into practice. The antibacterial action involves inhibition of protein synthesis in the bacterial cell during translocation. Resistance to spiramycin can develop by several mechanisms and its prevalence is to a considerable extent proportional to the frequency of prescription in a given area. The antibacterial spectrum comprises Gram-positive cocci and rods, Gram-negative cocci and also Legionellae, mycoplasmas, chlamydiae, some types of spirochetes, Toxoplasma gondii and Cryptosporidium sp., Enterobacteria, pseudomonads and pathogenic moulds are resistant. Its action is mainly bacteriostatic, on highly sensitive strains it exerts a bactericide action. As compared with erythromycin, it is in vitro weight for weight 5 to 20 less effective, an equipotential therapeutic dose is, however, only double. This difference between the effectiveness in vitro and in vivo is explained above all by the great affinity of spiramycin to tissues where it achieves concentrations many times higher than serum levels. An important part is played also by the slow release of the antibiotic from the tissue compartment, the marked action on microbes in sub-inhibition concentrations and the relatively long persisting post-antibiotic effect. Its great advantage is the exceptionally favourable tolerance-gastrointestinal and general. It is available for parenteral and oral administration.(ABSTRACT TRUNCATED AT 250 WORDS)