Cethromycin is a macrolide antibiotic which displays in vitro activity against both gram-positive and gram-negative bacteria and is currently under investigation for the treatment of community-acquired pneumonia. The US Food and Drug Administration (FDA) have also granted orphan drug designation to cethromycin for the treatment of anthrax prophylaxis, tularemia, and plague (PDB entry: 1NWX). It has a role as an antibacterial drug and a protein synthesis inhibitor.