Comparative efficacy and toxicity of roxithromycin and erythromycin ethylsuccinate in the treatment of streptococcal pharyngitis in adults.

Roxithromycin is a novel oxime ether derivative of erythromycin. Previous studies have demonstrated similar in-vitro activity for roxithromycin and erythromycin. Roxithromycin has improved pharmacokinetic properties and may be a useful alternative agent for infections where erythromycin is indicated. We compared the efficacy and toxicity of roxithromycin and erythromycin ethylsuccinate in the treatment of streptococcal pharyngitis in adults. We also assessed compliance with treatment between the two agents. Roxithromycin and erythromycin ethylsuccinate were equally effective in resolving the symptoms and signs of pharyngitis. Erythromycin ethylsuccinate was superior to roxithromycin in achieving microbiological cure (90% vs. 33%, respectively). No differences were observed in toxicity or compliance with treatment between the two agents. Based on this prespective clinical trial, roxithromycin is not considered to be an acceptable alternative agent for acute streptococcal pharyngitis in adults.