Amfenicols

Amfenicols are broad-spectrum bacteriostatic antibiotics, including chloramphenicol, thiamphenicol, and florfenicol. They inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit and blocking peptidyl transferase activity. Amfenicols are active against Gram-positive and Gram-negative bacteria, anaerobes, and atypical pathogens. Although chloramphenicol has strong efficacy and excellent tissue penetration, its risk of aplastic anemia and bone marrow suppression limits systemic use. Newer derivatives such as florfenicol improve safety while retaining antimicrobial activity, making them valuable in veterinary medicine and specific human infections. These antibiotics remain important alternatives for resistant or severe infections where other classes are ineffective.