Azalides such as azithromycin are a class of macrolide antibiotics that were originally manufactured in response to the poor acid stability exhibited by original macrolides (erythromycin). Following the clinical overuse of macrolides and azalides, ketolides have been developed to combat surfacing macrolide-azalide resistance among streptococci species.
Azalides, like azithromycin, are a class of macrolide antibiotics that were initially developed to address the acid instability issues found in original macrolides (erythromycin).  The emergence of macrolide-azalide resistance among streptococci species has led to the development of ketolides as an alternative.