Tigecycline is a broad spectrum glycylcycline antibiotic. Tigecycline is bacteriostatic. It inhibits protein synthesis through the binding of the 30S ribosomal subunit of bacteria. This blocks entry of Aminoacyl-tRNA into the A site of the ribosome during translation. Tigecycline is active against resistant strains of gram-positive and gram-negative bacteria, avoiding the two most common mechanisms of resistance to the tetracycline antimicrobials: tetracycline efflux pump proteins and ribosomal protection proteins.