About DIFICID® (fidaxomicin) TabletsDIFICID is the first macrolide antibacterial drug indicated for Clostridium difficile-associated diarrhea (CDAD) to be approved in over 25 years in the U.S. It is indicated for the treatment of CDAD in adults 18 years of age or older. DIFICID is administered in 200 mg tablets given orally twice daily. Important Safety Information for DIFICID DIFICID is contraindicated in patients with hypersensitivity to fidaxomicin or to any of the excipients in the formulation. DIFICID should not be used for systemic infections. Only use DIFICID for infection proven or strongly suspected to be caused by C. difficile. Prescribing DIFICID in the absence of a proven or strongly suspected C. difficile infection is unlikely to provide benefit to the patient and increases the risk of the development of drug resistant bacteria. The most common adverse reactions are nausea (11%), vomiting (7%), abdominal pain (6%), gastrointestinal hemorrhage (4%), anemia (2%) and neutropenia (2%). Please visit www.DIFICID.com or call 855-DIFICID (343-4243) for full prescribing information for DIFICID. About Optimer Pharmaceuticals Optimer Pharmaceuticals, Inc. is a global biopharmaceutical company focused on developing and commercializing innovative hospital specialty products that have a positive impact on society. Optimer developed DIFICID® (fidaxomicin) tablets, an FDA-approved macrolide antibacterial drug for the treatment of Clostridium difficile-associated diarrhea (CDAD) in adults 18 years of age and older and is commercializing DIFICID in the US and Canada. Optimer also received marketing authorization for fidaxomicin tablets in the European Union where its partner, Astellas Pharma Europe, is commercializing fidaxomicin under the trade name DIFICLIR™. The Company is exploring marketing authorization in other parts of the world where C. difficile has emerged as a serious health problem, including Asia. Additional information can be found at http://www.optimerpharma.com.