Boxed warning (hypersensitivity reactions including anaphylaxis): Patients treated with enzyme replacement therapies have experienced life-threatening hypersensitivity reactions, including anaphylaxis. Anaphylaxis has occurred during the early course of enzyme replacement therapy and after extended duration of therapy. Infusion-Associated Reactions (IARs): If a severe IAR occurs, discontinue CEREZYME immediately and initiate appropriate medical treatment. Hypersensitivity Reactions Including Anaphylaxis Life-threatening hypersensitivity reactions, including anaphylaxis, have been reported in patients treated with enzyme replacement therapies, including CEREZYME. In addition, other hypersensitivity reactions have included pruritus, flushing, urticaria, angioedema, chest discomfort, dyspnea, cough, cyanosis, tachycardia, and hypotension.