Avibactam (formerly NXL104, AVE1330A) is a synthetic non-β-lactam, covalent, slowly reversible β-lactamase inhibitor that inhibits the activities of Ambler class A and C β-lactamases and some Ambler class D enzymes. The combination of ceftazidime with avibactam exhibited broad-spectrum activity against Ambler class A- and class C-producing Enterobacteriaceae. AVYCAZ is a combination of ceftazidime, a cephalosporin, and avibactam indicated for the treatment of patients with the following infections caused by designated susceptible microorganisms: Complicated Intra-abdominal Infections, used in combination with metronidazole and Complicated Urinary Tract Infections, including Pyelonephritis.