Cilastatin sodium salt is primarily used in clinical medicine as a renal dehydropeptidase-I inhibitor. It is co-administered with the antibiotic imipenem to prevent the degradation of imipenem in the kidneys. By inhibiting the enzyme dehydropeptidase-I, cilastatin prolongs the active life of imipenem in the body, enhancing its antibacterial efficacy. This combination is effective against a broad spectrum of Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa and other resistant strains. The use of cilastatin ensures higher urinary concentrations of imipenem, making the treatment more effective in severe infections such as sepsis, intra-abdominal infections, and urinary tract infections. It does not possess significant antimicrobial activity on its own but is crucial for optimizing the pharmacokinetics and therapeutic effectiveness of imipenem.