Doripenem, a semi-synthetic carbapenem antibiotic featuring an unusual sulfamoylamino terminus, was commercially developed in the early 1990s by Shionogi Co., Japan. Doripenem acts by preventing bacterial cell wall growth by binding to penicillin-binding proteins. Doripenem possesses a broad antibacterial spectrum of action against Gram positive and Gram negative bacteria, including Pseudomonas, and is stable to most β-lactamases. Dorapenem is supplied as the hydrate.