In-vitro activity of roxithromycin against respiratory and skin pathogens.

The activity of roxithromycin was determined by a microdilution method, in comparison with erythromycin, spiramycin and josamycin. Roxithromycin and erythromycin showed very similar MICs against staphylococci, Streptococcus pneumoniae, Str. pyogenes and Haemophilus influenzae. In most cases, spiramycin and josamycin appeared similarly or more active. The activity of roxithromycin against Mycoplasma pneumoniae, Legionella spp., Chlamydia psittaci and, to some extent, against Pasteurella spp. was also assessed, by suitable in-vitro methods. Roxithromycin has a promising potential for treating selected skin and respiratory infections.