Abstract
OBJECTIVE: To compare the pharmacokinetic properties of two new macrolide antibiotics, clarithromycin and azithromycin, with those of the prototype macrolide, erythromycin. DATA SOURCES: Primarily peer review journals were searched for papers describing the pharmacokinetics of these new macrolides. STUDY SELECTION: Fifteen in vitro and clinical studies of clarithromycin and azithromycin and one clinical abstract on clarithromycin from the past four years were selected for review. DATA EXTRACTION: Data relevant to the pharmacokinetic characteristics of clarithromycin, azithromycin and, to a lesser extent, erythromycin were selected for presentation in this comparison. DATA SYNTHESIS: By reviewing the available studies, it was possible to construct pharmacokinetic profiles of the new compounds, and to compare them with each other and with erythromycin. CONCLUSIONS: Both clarithromycin and azithromycin have been shown to have an antibacterial spectrum and pharmacokinetic profile superior to that of erythromycin. The differences between the new compounds, however, may not be that significant. Each is likely to become a first-line therapeutic option in specific instances, which will become better delineated as clinical research on these new macrolides continues.