Relebactam is a chemical compound used in combination with antibiotics to improve their efficacy. As a beta-lactamase inhibitor, it blocks the ability of bacteria to break down a beta-lactam antibiotic. In the United States, relebactam is approved for use in the combination imipenem/cilastatin/relebactam (Recarbrio). Relebactam is a chemical compound used in combination with antibiotics to improve their efficacy. As a beta-lactamase inhibitor, it blocks the ability of bacteria to break down a beta-lactam antibiotic. In the United States, relebactam is approved for use in the combination imipenem/cilastatin/relebactam (Recarbrio).