Dirithromycin is a macrolide antibiotic. It is a prodrug of erythromycylamine that has outstanding activity against Campylobacter. Dirithromycin is a group 3 agent with respect to its interaction with the cytochrome P450 (CYP) isoform 3A4, as it interferes poorly with CYP3A4 in vitro and generally does not alter drug metabolism in vivo.