Imipenem is an antibacterial agent of the carbapenem class of beta-lactams, with a very broad spectrum of activity that includes most Gram-negative and Gram-positive pathogens, aerobes and anaerobes, and with marked activity against species producing beta-lactamases. It is coadministered with cilastatin, a renal dehydropeptidase inhibitor that prevents renal metabolism of imipenem. As initial monotherapy, imipenem/cilastatin provides effective and well-tolerated treatment of moderate to severe infections in various body systems, including intra-abdominal, obstetric and gynaecological, lower respiratory tract, skin and soft tissue, and urinary tract infections, and also in bacteraemia and septicaemia, and in patients with malignancy-related febrile neutropenia. It is likely to be of particular benefit in cases where bacterial pathogens have not yet been identified, such as in the treatment of serious infections in immunocompromised patients, or in an intensive care setting. Thus, imipenem/cilastatin is effective as initial monotherapy of a variety of infections, including infections in neutropenic patients, with a clear role in empirical treatment of mixed infection.